Transaction Management Guide

<h2 id="transaction-management-guide" class="position-relative d-flex align-items-center group"> Transaction Management Guide <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="transaction-management-guide" aria-haspopup="dialog" aria-label="Share link: Transaction Management Guide"> Share link </button> </h2><div id="headingShareModal" class="heading-share-modal" role="dialog" aria-modal="true" aria-labelledby="headingShareTitle" hidden> <div class="hsm-dialog" role="document"> <div class="hsm-header"> <h2 id="headingShareTitle" class="h6 mb-0 fw-bold">Share this section</h2> <button type="button" class="hsm-close" aria-label="Close"> </button> </div> <div class="hsm-body"> <label for="headingShareInput" class="form-label small text-muted mb-1 text-uppercase fw-bold" style="font-size: 0.7rem; letter-spacing: 0.5px;">Permalink</label> <div class="input-group mb-4 hsm-url-group"> <input id="headingShareInput" type="text" class="form-control font-monospace" readonly aria-readonly="true" style="font-size: 0.85rem;" /> <button class="btn btn-primary hsm-copy" type="button" aria-label="Copy" title="Copy"> </button> </div> <div class="small fw-bold mb-2 text-muted text-uppercase" style="font-size: 0.7rem; 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This guide covers ACID guarantees, isolation levels, transaction patterns, and best practices for building reliable applications. <h3 id="understanding-acid-guarantees" class="position-relative d-flex align-items-center group"> Understanding ACID Guarantees <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="understanding-acid-guarantees" aria-haspopup="dialog" aria-label="Share link: Understanding ACID Guarantees"> Share link </button> </h3>Geode provides full ACID compliance for all transactions. <h4 id="atomicity" class="position-relative d-flex align-items-center group"> Atomicity <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="atomicity" aria-haspopup="dialog" aria-label="Share link: Atomicity"> Share link </button> </h4>All or nothing: Either all operations in a transaction succeed, or none do. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">BEGIN -- These operations are atomic CREATE (:Account {id: 1, balance: 1000}) CREATE (:Account {id: 2, balance: 500}) MATCH (a:Account {id: 1}), (b:Account {id: 2}) CREATE (a)-[:TRANSFER {amount: 100, timestamp: timestamp()}]->(b) MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100 MATCH (b:Account {id: 2}) SET b.balance = b.balance + 100 COMMIT -- If any operation fails, all changes are rolled back </code></pre></div> <h4 id="consistency" class="position-relative d-flex align-items-center group"> Consistency <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="consistency" aria-haspopup="dialog" aria-label="Share link: Consistency"> Share link </button> </h4>Valid state transitions: Transactions move the database from one valid state to another. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Constraints ensure consistency CREATE CONSTRAINT account_balance_positive ON :Account(balance) ASSERT balance >= 0 -- This transaction will fail if it would make balance negative BEGIN MATCH (a:Account {id: 1}) SET a.balance = a.balance - 2000 COMMIT -- Fails: constraint violation, transaction rolled back </code></pre></div> <h4 id="isolation" class="position-relative d-flex align-items-center group"> Isolation <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="isolation" aria-haspopup="dialog" aria-label="Share link: Isolation"> Share link </button> </h4>Concurrent transactions don’t interfere: Each transaction sees a consistent view of data. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">-- Transaction 1 -- Transaction 2 BEGIN BEGIN MATCH (a:Account {id: 1}) MATCH (a:Account {id: 1}) -- sees balance = 1000 -- also sees balance = 1000 SET a.balance = 900 SET a.balance = 800 COMMIT COMMIT -- One transaction will be serialized -- No lost updates </code></pre></div> <h4 id="durability" class="position-relative d-flex align-items-center group"> Durability <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="durability" aria-haspopup="dialog" aria-label="Share link: Durability"> Share link </button> </h4>Committed data persists: Once committed, data survives system failures. <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-gql" data-lang="gql">BEGIN CREATE (:ImportantData {value: "critical"}) COMMIT -- Data is written to disk before commit returns -- Survives power loss, crashes, etc. </code></pre></div> <h3 id="transaction-isolation-levels" class="position-relative d-flex align-items-center group"> Transaction Isolation Levels <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="transaction-isolation-levels" aria-haspopup="dialog" aria-label="Share link: Transaction Isolation Levels"> Share link </button> </h3>Geode supports multiple isolation levels to balance consistency and performance. <h4 id="available-isolation-levels" class="position-relative d-flex align-items-center group"> Available Isolation Levels <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="available-isolation-levels" aria-haspopup="dialog" aria-label="Share link: Available Isolation Levels"> Share link </button> </h4><table> <thead> <tr> <th>Level</th> <th>Dirty Reads</th> <th>Non-repeatable Reads</th> <th>Phantom Reads</th> <th>Description</th> </tr> </thead> <tbody> <tr> <td>READ UNCOMMITTED</td> <td>Yes</td> <td>Yes</td> <td>Yes</td> <td>Lowest isolation, highest performance</td> </tr> <tr> <td>READ COMMITTED</td> <td>No</td> <td>Yes</td> <td>Yes</td> <td>Default level, sees committed data only</td> </tr> <tr> <td>REPEATABLE READ</td> <td>No</td> <td>No</td> <td>Yes</td> <td>Consistent reads within transaction</td> </tr> <tr> <td>SERIALIZABLE</td> <td>No</td> <td>No</td> <td>No</td> <td>Highest isolation, transactions appear sequential</td> </tr> </tbody> </table> <h4 id="setting-isolation-level" class="position-relative d-flex align-items-center group"> Setting Isolation Level <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="setting-isolation-level" aria-haspopup="dialog" aria-label="Share link: Setting Isolation Level"> Share link </button> </h4><div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880881832930056" 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"localhost:3141") if err != nil { log.Fatal(err) } defer db.Close() ctx := context.Background() // Start transaction with specific isolation level tx, err := db.BeginTx(ctx, &sql.TxOptions{ Isolation: sql.LevelSerializable, }) if err != nil { log.Fatal(err) } // Execute operations _, err = tx.ExecContext(ctx, ` MATCH (a:Account {id: ?}) SET a.balance = a.balance - ? `, 1, 100) if err != nil { tx.Rollback() log.Fatal(err) } _, err = tx.ExecContext(ctx, ` MATCH (a:Account {id: ?}) SET a.balance = a.balance + ? `, 2, 100) if err != nil { tx.Rollback() log.Fatal(err) } if err := tx.Commit(); err != nil { log.Fatal(err) } log.Println("Transfer completed successfully") } // Different isolation levels for different use cases func readOnlyQuery(db *sql.DB) { ctx := context.Background() // Read committed is sufficient for read-only queries tx, _ := db.BeginTx(ctx, &sql.TxOptions{ Isolation: sql.LevelReadCommitted, ReadOnly: true, }) defer tx.Rollback() rows, _ := tx.QueryContext(ctx, "MATCH (n) RETURN count(n)") defer rows.Close() // Process results } func criticalFinancialOperation(db *sql.DB) { ctx := context.Background() // Serializable for critical operations tx, _ := db.BeginTx(ctx, &sql.TxOptions{ Isolation: sql.LevelSerializable, }) defer func() { if r := recover(); r != nil { tx.Rollback() } }() // Critical operations here tx.Commit() } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881832930056-tab-1" role="tabpanel" aria-labelledby="tabs-1774880881832930056-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">import asyncio from enum import Enum from geode_client import Client, IsolationLevel class TransactionIsolation(Enum): READ_UNCOMMITTED = "read_uncommitted" READ_COMMITTED = "read_committed" REPEATABLE_READ = "repeatable_read" SERIALIZABLE = "serializable" async def transfer_funds( client: Client, from_account: int, to_account: int, amount: float, isolation: TransactionIsolation = TransactionIsolation.SERIALIZABLE ) -> None: """Transfer funds between accounts with specified isolation level.""" async with client.connection() as conn: # Begin transaction with isolation level await conn.begin(isolation_level=isolation.value) try: # Debit source account await conn.execute(""" MATCH (a:Account {id: $id}) SET a.balance = a.balance - $amount """, {"id": from_account, "amount": amount}) # Credit destination account await conn.execute(""" MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount """, {"id": to_account, "amount": amount}) await conn.commit() print("Transfer completed successfully") except Exception as e: await conn.rollback() print(f"Transfer failed: {e}") raise async def read_only_query(client: Client) -> int: """Execute read-only query with appropriate isolation.""" async with client.connection() as conn: # Read committed is sufficient for read-only await conn.begin( isolation_level="read_committed", read_only=True ) try: result, _ = await conn.query("MATCH (n) RETURN count(n) as count") count = result.rows[0]["count"].as_int if result.rows else 0 await conn.commit() return count except Exception: await conn.rollback() raise async def critical_operation(client: Client) -> None: """Execute critical operation with serializable isolation.""" async with client.connection() as conn: await conn.begin(isolation_level="serializable") try: # Check preconditions result, _ = await conn.query(""" MATCH (a:Account {id: 1}) RETURN a.balance as balance """) balance = result.rows[0]["balance"].as_float if result.rows else 0 if balance < 100: raise ValueError("Insufficient funds") # Perform critical update await conn.execute(""" MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100 """) await conn.commit() except Exception as e: await conn.rollback() raise async def main(): client = Client(host="localhost", port=3141, skip_verify=True) # Different isolation for different operations await transfer_funds( client, 1, 2, 100.0, isolation=TransactionIsolation.SERIALIZABLE ) count = await read_only_query(client) print(f"Total nodes: {count}") if __name__ == "__main__": asyncio.run(main()) </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881832930056-tab-2" role="tabpanel" aria-labelledby="tabs-1774880881832930056-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">use geode_client::{Client, Connection, IsolationLevel, TransactionOptions, Value}; use std::collections::HashMap; async fn transfer_funds( conn: &mut Connection, from_account: i64, to_account: i64, amount: f64, isolation: IsolationLevel, ) -> Result<(), Box<dyn std::error::Error>> { // Begin transaction with specified isolation level let options = TransactionOptions { isolation_level: isolation, read_only: false, }; conn.begin_with_options(options).await?; // Debit source account let mut params = HashMap::new(); params.insert("id".to_string(), Value::int(from_account)); params.insert("amount".to_string(), Value::float(amount)); match conn.query_with_params( "MATCH (a:Account {id: $id}) SET a.balance = a.balance - $amount", &params ).await { Ok(_) => {} Err(e) => { conn.rollback().await?; return Err(e.into()); } } // Credit destination account params.insert("id".to_string(), Value::int(to_account)); match conn.query_with_params( "MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount", &params ).await { Ok(_) => { conn.commit().await?; println!("Transfer completed successfully"); Ok(()) } Err(e) => { conn.rollback().await?; Err(e.into()) } } } async fn read_only_query(conn: &mut Connection) -> Result<i64, Box<dyn std::error::Error>> { // Read committed is sufficient for read-only let options = TransactionOptions { isolation_level: IsolationLevel::ReadCommitted, read_only: true, }; conn.begin_with_options(options).await?; let (page, _) = conn.query("MATCH (n) RETURN count(n) as count").await?; let count = page.rows.first() .and_then(|row| row.get("count")) .and_then(|v| v.as_int().ok()) .unwrap_or(0); conn.commit().await?; Ok(count) } async fn critical_operation(conn: &mut Connection) -> Result<(), Box<dyn std::error::Error>> { // Serializable for critical operations let options = TransactionOptions { isolation_level: IsolationLevel::Serializable, read_only: false, }; conn.begin_with_options(options).await?; // Check preconditions let (page, _) = conn.query( "MATCH (a:Account {id: 1}) RETURN a.balance as balance" ).await?; let balance = page.rows.first() .and_then(|row| row.get("balance")) .and_then(|v| v.as_float().ok()) .unwrap_or(0.0); if balance < 100.0 { conn.rollback().await?; return Err("Insufficient funds".into()); } // Perform critical update match conn.query( "MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100" ).await { Ok(_) => { conn.commit().await?; Ok(()) } Err(e) => { conn.rollback().await?; Err(e.into()) } } } #[tokio::main] async fn main() -> Result<(), Box<dyn std::error::Error>> { let client = Client::new("127.0.0.1", 3141).skip_verify(true); let mut conn = client.connect().await?; // Transfer with serializable isolation transfer_funds(&mut conn, 1, 2, 100.0, IsolationLevel::Serializable).await?; // Read-only query let count = read_only_query(&mut conn).await?; println!("Total nodes: {}", count); Ok(()) } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881832930056-tab-3" role="tabpanel" aria-labelledby="tabs-1774880881832930056-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">import { createClient, GeodeClient, IsolationLevel } from '@geodedb/client'; enum TransactionIsolation { READ_UNCOMMITTED = 'read_uncommitted', READ_COMMITTED = 'read_committed', REPEATABLE_READ = 'repeatable_read', SERIALIZABLE = 'serializable', } async function transferFunds( client: GeodeClient, fromAccount: number, toAccount: number, amount: number, isolation: TransactionIsolation = TransactionIsolation.SERIALIZABLE ): Promise<void> { await client.withTransaction( async (tx) => { // Debit source account await tx.exec( 'MATCH (a:Account {id: $id}) SET a.balance = a.balance - $amount', { params: { id: fromAccount, amount } } ); // Credit destination account await tx.exec( 'MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount', { params: { id: toAccount, amount } } ); }, { isolationLevel: isolation } ); console.log('Transfer completed successfully'); } async function readOnlyQuery(client: GeodeClient): Promise<number> { let count = 0; await client.withTransaction( async (tx) => { const rows = await tx.queryAll('MATCH (n) RETURN count(n) as count'); count = rows[0]?.get('count')?.asNumber || 0; }, { isolationLevel: TransactionIsolation.READ_COMMITTED, readOnly: true, } ); return count; } async function criticalOperation(client: GeodeClient): Promise<void> { await client.withTransaction( async (tx) => { // Check preconditions const rows = await tx.queryAll( 'MATCH (a:Account {id: 1}) RETURN a.balance as balance' ); const balance = rows[0]?.get('balance')?.asNumber || 0; if (balance < 100) { throw new Error('Insufficient funds'); } // Perform critical update await tx.exec( 'MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100' ); }, { isolationLevel: TransactionIsolation.SERIALIZABLE } ); } async function main() { const client = await createClient('quic://localhost:3141'); try { // Transfer with serializable isolation await transferFunds(client, 1, 2, 100, TransactionIsolation.SERIALIZABLE); // Read-only query const count = await readOnlyQuery(client); console.log(`Total nodes: ${count}`); // Critical operation await criticalOperation(client); } finally { await client.close(); } } main().catch(console.error); </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881832930056-tab-4" role="tabpanel" aria-labelledby="tabs-1774880881832930056-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">const std = @import("std"); const geode = @import("geode_client"); pub const IsolationLevel = enum { read_uncommitted, read_committed, repeatable_read, serializable, pub fn toString(self: IsolationLevel) []const u8 { return switch (self) { .read_uncommitted => "READ UNCOMMITTED", .read_committed => "READ COMMITTED", .repeatable_read => "REPEATABLE READ", .serializable => "SERIALIZABLE", }; } }; pub fn transferFunds( client: *geode.GeodeClient, from_account: i64, to_account: i64, amount: f64, isolation: IsolationLevel, ) !void { // Begin transaction with isolation level const begin_query = try std.fmt.allocPrint( client.allocator, "BEGIN ISOLATION LEVEL {s}", .{isolation.toString()}, ); defer client.allocator.free(begin_query); try client.sendRunGql(1, begin_query, null); _ = try client.receiveMessage(30000); // Debit source account var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("id", .{ .integer = from_account }); try params.put("amount", .{ .float = amount }); client.sendRunGql(2, "MATCH (a:Account {id: $id}) SET a.balance = a.balance - $amount", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Credit destination account params.clearRetainingCapacity(); try params.put("id", .{ .integer = to_account }); try params.put("amount", .{ .float = amount }); client.sendRunGql(3, "MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Commit try client.sendCommit(); _ = try client.receiveMessage(30000); std.debug.print("Transfer completed successfully\n", .{}); } pub fn readOnlyQuery(client: *geode.GeodeClient) !i64 { // Read committed is sufficient for read-only try client.sendRunGql(1, "BEGIN ISOLATION LEVEL READ COMMITTED READ ONLY", null); _ = try client.receiveMessage(30000); try client.sendRunGql(2, "MATCH (n) RETURN count(n) as count", null); _ = try client.receiveMessage(30000); try client.sendPull(2, 1000); const result = try client.receiveMessage(30000); defer client.allocator.free(result); try client.sendCommit(); _ = try client.receiveMessage(30000); // Parse count from result (simplified) // In practice, parse JSON to extract count value return 0; } pub fn criticalOperation(client: *geode.GeodeClient) !void { // Serializable for critical operations try client.sendRunGql(1, "BEGIN ISOLATION LEVEL SERIALIZABLE", null); _ = try client.receiveMessage(30000); // Check preconditions try client.sendRunGql(2, "MATCH (a:Account {id: 1}) RETURN a.balance as balance", null); _ = try client.receiveMessage(30000); try client.sendPull(2, 1000); const balance_result = try client.receiveMessage(30000); defer client.allocator.free(balance_result); // Parse and check balance (simplified) // In practice, parse JSON and check balance >= 100 // Perform critical update client.sendRunGql(3, "MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100", null) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); } pub fn main() !void { var gpa = std.heap.GeneralPurposeAllocator(.{}){}; defer _ = gpa.deinit(); const allocator = gpa.allocator(); var client = geode.GeodeClient.init(allocator, "localhost", 3141, true); defer client.deinit(); try client.connect(); try client.sendHello("app", "1.0.0"); _ = try client.receiveMessage(30000); // Transfer with serializable isolation try transferFunds(&client, 1, 2, 100.0, .serializable); // Read-only query const count = try readOnlyQuery(&client); std.debug.print("Total nodes: {d}\n", .{count}); // Critical operation try criticalOperation(&client); } </code></pre></div> </div></div> </div> <h3 id="starting-and-committing-transactions" class="position-relative d-flex align-items-center group"> Starting and Committing Transactions <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="starting-and-committing-transactions" aria-haspopup="dialog" aria-label="Share link: Starting and Committing Transactions"> Share link </button> </h3> <h4 id="basic-transaction-flow" class="position-relative d-flex align-items-center group"> Basic Transaction Flow <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="basic-transaction-flow" aria-haspopup="dialog" aria-label="Share link: Basic Transaction Flow"> Share link </button> </h4><div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880881874818081" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880881874818081-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881874818081-tab-0" type="button" role="tab" aria-controls="tabs-1774880881874818081-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881874818081-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881874818081-tab-1" type="button" role="tab" aria-controls="tabs-1774880881874818081-tab-1" aria-selected="false" > Python </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881874818081-tab-2-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881874818081-tab-2" type="button" role="tab" aria-controls="tabs-1774880881874818081-tab-2" aria-selected="false" > Rust </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881874818081-tab-3-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881874818081-tab-3" type="button" role="tab" aria-controls="tabs-1774880881874818081-tab-3" aria-selected="false" > Node.js </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881874818081-tab-4-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881874818081-tab-4" type="button" role="tab" aria-controls="tabs-1774880881874818081-tab-4" aria-selected="false" > Zig </button> </li></ul> <div class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880881874818081-content"><div class="tab-pane fade show active" id="tabs-1774880881874818081-tab-0" role="tabpanel" aria-labelledby="tabs-1774880881874818081-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">func basicTransaction(db *sql.DB) error { ctx := context.Background() // Begin transaction tx, err := db.BeginTx(ctx, nil) if err != nil { return fmt.Errorf("failed to begin transaction: %w", err) } // Ensure cleanup on panic defer func() { if r := recover(); r != nil { tx.Rollback() panic(r) } }() // Execute operations _, err = tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Alice") if err != nil { tx.Rollback() return fmt.Errorf("failed to create person: %w", err) } _, err = tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Bob") if err != nil { tx.Rollback() return fmt.Errorf("failed to create person: %w", err) } // Commit transaction if err := tx.Commit(); err != nil { return fmt.Errorf("failed to commit: %w", err) } return nil } // Helper function for transaction execution func withTransaction(db *sql.DB, fn func(tx *sql.Tx) error) error { ctx := context.Background() tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer func() { if r := recover(); r != nil { tx.Rollback() panic(r) } }() if err := fn(tx); err != nil { tx.Rollback() return err } return tx.Commit() } // Usage func main() { db, _ := sql.Open("geode", "localhost:3141") defer db.Close() err := withTransaction(db, func(tx *sql.Tx) error { ctx := context.Background() _, err := tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Alice") return err }) if err != nil { log.Fatal(err) } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881874818081-tab-1" role="tabpanel" aria-labelledby="tabs-1774880881874818081-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async def basic_transaction(client: Client) -> None: """Basic transaction with explicit begin/commit.""" async with client.connection() as conn: # Begin transaction await conn.begin() try: # Execute operations await conn.execute( "CREATE (:Person {name: $name})", {"name": "Alice"} ) await conn.execute( "CREATE (:Person {name: $name})", {"name": "Bob"} ) # Commit transaction await conn.commit() print("Transaction committed successfully") except Exception as e: # Rollback on error await conn.rollback() print(f"Transaction rolled back: {e}") raise # Context manager for automatic transaction handling class TransactionContext: def __init__(self, conn): self.conn = conn async def __aenter__(self): await self.conn.begin() return self.conn async def __aexit__(self, exc_type, exc_val, exc_tb): if exc_type is not None: await self.conn.rollback() return False await self.conn.commit() return True async def with_transaction(client: Client, operations) -> None: """Execute operations within a transaction context.""" async with client.connection() as conn: async with TransactionContext(conn): await operations(conn) # Usage async def main(): client = Client(host="localhost", port=3141, skip_verify=True) async def create_people(conn): await conn.execute( "CREATE (:Person {name: $name})", {"name": "Alice"} ) await conn.execute( "CREATE (:Person {name: $name})", {"name": "Bob"} ) await with_transaction(client, create_people) </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881874818081-tab-2" role="tabpanel" aria-labelledby="tabs-1774880881874818081-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn basic_transaction(conn: &mut Connection) -> Result<(), Error> { // Begin transaction conn.begin().await?; // Execute operations let result = async { let mut params = HashMap::new(); params.insert("name".to_string(), Value::string("Alice")); conn.query_with_params( "CREATE (:Person {name: $name})", &params ).await?; params.insert("name".to_string(), Value::string("Bob")); conn.query_with_params( "CREATE (:Person {name: $name})", &params ).await?; Ok::<(), Error>(()) }.await; match result { Ok(_) => { conn.commit().await?; println!("Transaction committed successfully"); Ok(()) } Err(e) => { conn.rollback().await?; println!("Transaction rolled back: {}", e); Err(e) } } } // Helper function for transaction execution async fn with_transaction<F, Fut, T>( conn: &mut Connection, operations: F ) -> Result<T, Error> where F: FnOnce(&mut Connection) -> Fut, Fut: std::future::Future<Output = Result<T, Error>>, { conn.begin().await?; match operations(conn).await { Ok(result) => { conn.commit().await?; Ok(result) } Err(e) => { let _ = conn.rollback().await; Err(e) } } } // Usage #[tokio::main] async fn main() -> Result<(), Box<dyn std::error::Error>> { let client = Client::new("127.0.0.1", 3141).skip_verify(true); let mut conn = client.connect().await?; with_transaction(&mut conn, |conn| async move { let mut params = HashMap::new(); params.insert("name".to_string(), Value::string("Alice")); conn.query_with_params( "CREATE (:Person {name: $name})", &params ).await?; Ok(()) }).await?; Ok(()) } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881874818081-tab-3" role="tabpanel" aria-labelledby="tabs-1774880881874818081-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function basicTransaction(client: GeodeClient): Promise<void> { // Using withTransaction helper await client.withTransaction(async (tx) => { // Execute operations await tx.exec( 'CREATE (:Person {name: $name})', { params: { name: 'Alice' } } ); await tx.exec( 'CREATE (:Person {name: $name})', { params: { name: 'Bob' } } ); // Transaction auto-commits on success }); console.log('Transaction committed successfully'); } // Manual transaction control async function manualTransaction(client: GeodeClient): Promise<void> { const conn = await client.getConnection(); try { await conn.begin(); await conn.exec( 'CREATE (:Person {name: $name})', { params: { name: 'Alice' } } ); await conn.exec( 'CREATE (:Person {name: $name})', { params: { name: 'Bob' } } ); await conn.commit(); console.log('Transaction committed successfully'); } catch (error) { await conn.rollback(); console.error('Transaction rolled back:', error); throw error; } finally { conn.release(); } } // Helper function async function withTransaction<T>( client: GeodeClient, operations: (tx: Transaction) => Promise<T> ): Promise<T> { return client.withTransaction(operations); } // Usage async function main() { const client = await createClient('quic://localhost:3141'); try { await withTransaction(client, async (tx) => { await tx.exec( 'CREATE (:Person {name: $name})', { params: { name: 'Alice' } } ); }); } finally { await client.close(); } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881874818081-tab-4" role="tabpanel" aria-labelledby="tabs-1774880881874818081-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">const std = @import("std"); const geode = @import("geode_client"); pub fn basicTransaction(client: *geode.GeodeClient) !void { // Begin transaction try client.sendBegin(); _ = try client.receiveMessage(30000); // Execute operations var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); // Create Alice try params.put("name", .{ .string = "Alice" }); client.sendRunGql(1, "CREATE (:Person {name: $name})", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Create Bob params.clearRetainingCapacity(); try params.put("name", .{ .string = "Bob" }); client.sendRunGql(2, "CREATE (:Person {name: $name})", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Commit transaction try client.sendCommit(); _ = try client.receiveMessage(30000); std.debug.print("Transaction committed successfully\n", .{}); } // Helper for transaction execution pub fn withTransaction( client: *geode.GeodeClient, comptime operations: fn (*geode.GeodeClient) anyerror!void, ) !void { try client.sendBegin(); _ = try client.receiveMessage(30000); operations(client) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; try client.sendCommit(); _ = try client.receiveMessage(30000); } pub fn main() !void { var gpa = std.heap.GeneralPurposeAllocator(.{}){}; defer _ = gpa.deinit(); const allocator = gpa.allocator(); var client = geode.GeodeClient.init(allocator, "localhost", 3141, true); defer client.deinit(); try client.connect(); try client.sendHello("app", "1.0.0"); _ = try client.receiveMessage(30000); try withTransaction(&client, struct { fn op(c: *geode.GeodeClient) !void { try c.sendRunGql(1, "CREATE (:Person {name: 'Alice'})", null); _ = try c.receiveMessage(30000); } }.op); } </code></pre></div> </div></div> </div> <h3 id="rollback-and-savepoints" class="position-relative d-flex align-items-center group"> Rollback and Savepoints <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="rollback-and-savepoints" aria-haspopup="dialog" aria-label="Share link: Rollback and Savepoints"> Share link </button> </h3>Savepoints allow partial rollback within a transaction. <h4 id="using-savepoints" class="position-relative d-flex align-items-center group"> Using Savepoints <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="using-savepoints" aria-haspopup="dialog" aria-label="Share link: Using Savepoints"> Share link </button> </h4><div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880881903132634" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880881903132634-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881903132634-tab-0" type="button" role="tab" aria-controls="tabs-1774880881903132634-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881903132634-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881903132634-tab-1" type="button" role="tab" aria-controls="tabs-1774880881903132634-tab-1" aria-selected="false" > Python </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881903132634-tab-2-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881903132634-tab-2" type="button" role="tab" aria-controls="tabs-1774880881903132634-tab-2" aria-selected="false" > Rust </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881903132634-tab-3-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881903132634-tab-3" type="button" role="tab" aria-controls="tabs-1774880881903132634-tab-3" aria-selected="false" > Node.js </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881903132634-tab-4-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881903132634-tab-4" type="button" role="tab" aria-controls="tabs-1774880881903132634-tab-4" aria-selected="false" > Zig </button> </li></ul> <div class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880881903132634-content"><div class="tab-pane fade show active" id="tabs-1774880881903132634-tab-0" role="tabpanel" aria-labelledby="tabs-1774880881903132634-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">func transactionWithSavepoints(db *sql.DB) error { ctx := context.Background() tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer tx.Rollback() // Create first person _, err = tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Alice") if err != nil { return err } // Create savepoint _, err = tx.ExecContext(ctx, "SAVEPOINT sp1") if err != nil { return err } // Try to create second person (might fail) _, err = tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Bob") if err != nil { // Rollback to savepoint, keeping Alice _, rollbackErr := tx.ExecContext(ctx, "ROLLBACK TO SAVEPOINT sp1") if rollbackErr != nil { return rollbackErr } log.Printf("Rolled back to savepoint: %v", err) } // Create third person _, err = tx.ExecContext(ctx, "CREATE (:Person {name: ?})", "Charlie") if err != nil { return err } return tx.Commit() } // Nested savepoints func nestedSavepoints(db *sql.DB) error { ctx := context.Background() tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer tx.Rollback() // Level 1: Create order _, _ = tx.ExecContext(ctx, "CREATE (:Order {id: 1})") _, _ = tx.ExecContext(ctx, "SAVEPOINT order_items") // Level 2: Add items _, _ = tx.ExecContext(ctx, "CREATE (:Item {orderId: 1, product: 'Widget'})") _, _ = tx.ExecContext(ctx, "SAVEPOINT item_inventory") // Level 3: Update inventory _, err = tx.ExecContext(ctx, "MATCH (i:Inventory {product: 'Widget'}) SET i.count = i.count - 1") if err != nil { // Rollback inventory update, keep items tx.ExecContext(ctx, "ROLLBACK TO SAVEPOINT item_inventory") } // Release savepoint (optional cleanup) tx.ExecContext(ctx, "RELEASE SAVEPOINT order_items") return tx.Commit() } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881903132634-tab-1" role="tabpanel" aria-labelledby="tabs-1774880881903132634-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async def transaction_with_savepoints(client: Client) -> None: """Use savepoints for partial rollback.""" async with client.connection() as conn: await conn.begin() try: # Create first person await conn.execute( "CREATE (:Person {name: $name})", {"name": "Alice"} ) # Create savepoint await conn.savepoint("sp1") try: # Try to create second person (might fail) await conn.execute( "CREATE (:Person {name: $name})", {"name": "Bob"} ) except Exception as e: # Rollback to savepoint, keeping Alice await conn.rollback_to_savepoint("sp1") print(f"Rolled back to savepoint: {e}") # Create third person await conn.execute( "CREATE (:Person {name: $name})", {"name": "Charlie"} ) await conn.commit() except Exception as e: await conn.rollback() raise async def nested_savepoints(client: Client) -> None: """Use nested savepoints for complex transactions.""" async with client.connection() as conn: await conn.begin() try: # Level 1: Create order await conn.execute("CREATE (:Order {id: 1})") await conn.savepoint("order_items") # Level 2: Add items await conn.execute( "CREATE (:Item {orderId: 1, product: $product})", {"product": "Widget"} ) await conn.savepoint("item_inventory") try: # Level 3: Update inventory await conn.execute(""" MATCH (i:Inventory {product: $product}) SET i.count = i.count - 1 """, {"product": "Widget"}) except Exception: # Rollback inventory update, keep items await conn.rollback_to_savepoint("item_inventory") print("Inventory update failed, items preserved") # Release savepoint (optional cleanup) await conn.release_savepoint("order_items") await conn.commit() except Exception: await conn.rollback() raise # Savepoint context manager class SavepointContext: def __init__(self, conn, name: str): self.conn = conn self.name = name self.released = False async def __aenter__(self): await self.conn.savepoint(self.name) return self async def __aexit__(self, exc_type, exc_val, exc_tb): if exc_type is not None: await self.conn.rollback_to_savepoint(self.name) return True # Suppress exception if not self.released: await self.conn.release_savepoint(self.name) return False async def release(self): await self.conn.release_savepoint(self.name) self.released = True # Usage async def with_savepoint_context(client: Client) -> None: async with client.connection() as conn: await conn.begin() await conn.execute("CREATE (:Person {name: 'Alice'})") async with SavepointContext(conn, "sp1"): await conn.execute("CREATE (:Person {name: 'Bob'})") # If this fails, rollback to sp1 automatically await conn.commit() </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881903132634-tab-2" role="tabpanel" aria-labelledby="tabs-1774880881903132634-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn transaction_with_savepoints(conn: &mut Connection) -> Result<(), Error> { conn.begin().await?; // Create first person let mut params = HashMap::new(); params.insert("name".to_string(), Value::string("Alice")); conn.query_with_params("CREATE (:Person {name: $name})", &params).await?; // Create savepoint conn.savepoint("sp1").await?; // Try to create second person (might fail) params.insert("name".to_string(), Value::string("Bob")); if let Err(e) = conn.query_with_params( "CREATE (:Person {name: $name})", &params ).await { // Rollback to savepoint, keeping Alice conn.rollback_to_savepoint("sp1").await?; println!("Rolled back to savepoint: {}", e); } // Create third person params.insert("name".to_string(), Value::string("Charlie")); conn.query_with_params("CREATE (:Person {name: $name})", &params).await?; conn.commit().await?; Ok(()) } async fn nested_savepoints(conn: &mut Connection) -> Result<(), Error> { conn.begin().await?; // Level 1: Create order conn.query("CREATE (:Order {id: 1})").await?; conn.savepoint("order_items").await?; // Level 2: Add items let mut params = HashMap::new(); params.insert("product".to_string(), Value::string("Widget")); conn.query_with_params( "CREATE (:Item {orderId: 1, product: $product})", &params ).await?; conn.savepoint("item_inventory").await?; // Level 3: Update inventory if let Err(_) = conn.query_with_params( "MATCH (i:Inventory {product: $product}) SET i.count = i.count - 1", &params ).await { // Rollback inventory update, keep items conn.rollback_to_savepoint("item_inventory").await?; println!("Inventory update failed, items preserved"); } // Release savepoint (optional cleanup) conn.release_savepoint("order_items").await?; conn.commit().await?; Ok(()) } // Helper struct for savepoint scope struct SavepointGuard<'a> { conn: &'a mut Connection, name: String, released: bool, } impl<'a> SavepointGuard<'a> { async fn new(conn: &'a mut Connection, name: &str) -> Result<Self, Error> { conn.savepoint(name).await?; Ok(Self { conn, name: name.to_string(), released: false, }) } async fn release(&mut self) -> Result<(), Error> { self.conn.release_savepoint(&self.name).await?; self.released = true; Ok(()) } async fn rollback(&mut self) -> Result<(), Error> { self.conn.rollback_to_savepoint(&self.name).await?; self.released = true; Ok(()) } } impl<'a> Drop for SavepointGuard<'a> { fn drop(&mut self) { if !self.released { // In async context, we can't await here // Consider using explicit release/rollback } } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881903132634-tab-3" role="tabpanel" aria-labelledby="tabs-1774880881903132634-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function transactionWithSavepoints(client: GeodeClient): Promise<void> { await client.withTransaction(async (tx) => { // Create first person await tx.exec('CREATE (:Person {name: $name})', { params: { name: 'Alice' } }); // Create savepoint await tx.savepoint('sp1'); try { // Try to create second person (might fail) await tx.exec('CREATE (:Person {name: $name})', { params: { name: 'Bob' } }); } catch (error) { // Rollback to savepoint, keeping Alice await tx.rollbackToSavepoint('sp1'); console.log('Rolled back to savepoint:', error); } // Create third person await tx.exec('CREATE (:Person {name: $name})', { params: { name: 'Charlie' } }); }); } async function nestedSavepoints(client: GeodeClient): Promise<void> { await client.withTransaction(async (tx) => { // Level 1: Create order await tx.exec('CREATE (:Order {id: 1})'); await tx.savepoint('order_items'); // Level 2: Add items await tx.exec( 'CREATE (:Item {orderId: 1, product: $product})', { params: { product: 'Widget' } } ); await tx.savepoint('item_inventory'); try { // Level 3: Update inventory await tx.exec( 'MATCH (i:Inventory {product: $product}) SET i.count = i.count - 1', { params: { product: 'Widget' } } ); } catch (error) { // Rollback inventory update, keep items await tx.rollbackToSavepoint('item_inventory'); console.log('Inventory update failed, items preserved'); } // Release savepoint (optional cleanup) await tx.releaseSavepoint('order_items'); }); } // Helper class for savepoint scope class SavepointScope { private released = false; constructor( private tx: Transaction, private name: string ) {} static async create(tx: Transaction, name: string): Promise<SavepointScope> { await tx.savepoint(name); return new SavepointScope(tx, name); } async release(): Promise<void> { if (!this.released) { await this.tx.releaseSavepoint(this.name); this.released = true; } } async rollback(): Promise<void> { if (!this.released) { await this.tx.rollbackToSavepoint(this.name); this.released = true; } } } // Usage async function withSavepointScope(client: GeodeClient): Promise<void> { await client.withTransaction(async (tx) => { await tx.exec('CREATE (:Person {name: $name})', { params: { name: 'Alice' } }); const scope = await SavepointScope.create(tx, 'sp1'); try { await tx.exec('CREATE (:Person {name: $name})', { params: { name: 'Bob' } }); await scope.release(); } catch (error) { await scope.rollback(); } }); } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881903132634-tab-4" role="tabpanel" aria-labelledby="tabs-1774880881903132634-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">const std = @import("std"); const geode = @import("geode_client"); pub fn transactionWithSavepoints(client: *geode.GeodeClient) !void { try client.sendBegin(); _ = try client.receiveMessage(30000); // Create first person var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("name", .{ .string = "Alice" }); try client.sendRunGql(1, "CREATE (:Person {name: $name})", .{ .object = params }); _ = try client.receiveMessage(30000); // Create savepoint try client.sendRunGql(2, "SAVEPOINT sp1", null); _ = try client.receiveMessage(30000); // Try to create second person (might fail) params.clearRetainingCapacity(); try params.put("name", .{ .string = "Bob" }); client.sendRunGql(3, "CREATE (:Person {name: $name})", .{ .object = params }) catch |e| { // Rollback to savepoint, keeping Alice try client.sendRunGql(4, "ROLLBACK TO SAVEPOINT sp1", null); _ = try client.receiveMessage(30000); std.debug.print("Rolled back to savepoint: {any}\n", .{e}); }; // Create third person params.clearRetainingCapacity(); try params.put("name", .{ .string = "Charlie" }); try client.sendRunGql(5, "CREATE (:Person {name: $name})", .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); } pub fn nestedSavepoints(client: *geode.GeodeClient) !void { try client.sendBegin(); _ = try client.receiveMessage(30000); // Level 1: Create order try client.sendRunGql(1, "CREATE (:Order {id: 1})", null); _ = try client.receiveMessage(30000); try client.sendRunGql(2, "SAVEPOINT order_items", null); _ = try client.receiveMessage(30000); // Level 2: Add items var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("product", .{ .string = "Widget" }); try client.sendRunGql(3, "CREATE (:Item {orderId: 1, product: $product})", .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendRunGql(4, "SAVEPOINT item_inventory", null); _ = try client.receiveMessage(30000); // Level 3: Update inventory client.sendRunGql(5, "MATCH (i:Inventory {product: $product}) SET i.count = i.count - 1", .{ .object = params }) catch |_| { // Rollback inventory update, keep items try client.sendRunGql(6, "ROLLBACK TO SAVEPOINT item_inventory", null); _ = try client.receiveMessage(30000); std.debug.print("Inventory update failed, items preserved\n", .{}); }; // Release savepoint try client.sendRunGql(7, "RELEASE SAVEPOINT order_items", null); _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); } </code></pre></div> </div></div> </div> <h3 id="optimistic-vs-pessimistic-concurrency" class="position-relative d-flex align-items-center group"> Optimistic vs Pessimistic Concurrency <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="optimistic-vs-pessimistic-concurrency" aria-haspopup="dialog" aria-label="Share link: Optimistic vs Pessimistic Concurrency"> Share link </button> </h3> <h4 id="optimistic-concurrency-control" class="position-relative d-flex align-items-center group"> Optimistic Concurrency Control <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="optimistic-concurrency-control" aria-haspopup="dialog" aria-label="Share link: Optimistic Concurrency Control"> Share link </button> </h4>Assumes conflicts are rare. Check for conflicts at commit time. <div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880881939411982" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880881939411982-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881939411982-tab-0" type="button" role="tab" aria-controls="tabs-1774880881939411982-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881939411982-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881939411982-tab-1" type="button" role="tab" aria-controls="tabs-1774880881939411982-tab-1" aria-selected="false" > Python </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881939411982-tab-2-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881939411982-tab-2" type="button" role="tab" aria-controls="tabs-1774880881939411982-tab-2" aria-selected="false" > Rust </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881939411982-tab-3-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881939411982-tab-3" type="button" role="tab" aria-controls="tabs-1774880881939411982-tab-3" aria-selected="false" > Node.js </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881939411982-tab-4-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881939411982-tab-4" type="button" role="tab" aria-controls="tabs-1774880881939411982-tab-4" aria-selected="false" > Zig </button> </li></ul> <div class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880881939411982-content"><div class="tab-pane fade show active" id="tabs-1774880881939411982-tab-0" role="tabpanel" aria-labelledby="tabs-1774880881939411982-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Optimistic concurrency with version checking func updateWithOptimisticLocking(db *sql.DB, personID int, newName string) error { ctx := context.Background() for attempts := 0; attempts < 3; attempts++ { tx, err := db.BeginTx(ctx, nil) if err != nil { return err } // Read current version var currentVersion int err = tx.QueryRowContext(ctx, ` MATCH (p:Person {id: ?}) RETURN p.version `, personID).Scan(&currentVersion) if err != nil { tx.Rollback() return err } // Update with version check result, err := tx.ExecContext(ctx, ` MATCH (p:Person {id: ?, version: ?}) SET p.name = ?, p.version = p.version + 1 `, personID, currentVersion, newName) if err != nil { tx.Rollback() return err } rowsAffected, _ := result.RowsAffected() if rowsAffected == 0 { tx.Rollback() // Concurrent modification detected, retry log.Printf("Optimistic lock conflict, attempt %d", attempts+1) time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond) continue } if err := tx.Commit(); err != nil { return err } return nil } return errors.New("failed after max retry attempts") } // Using timestamps instead of version numbers func updateWithTimestamp(db *sql.DB, personID int, newName string) error { ctx := context.Background() var lastModified time.Time err := db.QueryRowContext(ctx, ` MATCH (p:Person {id: ?}) RETURN p.modified_at `, personID).Scan(&lastModified) if err != nil { return err } result, err := db.ExecContext(ctx, ` MATCH (p:Person {id: ?}) WHERE p.modified_at = ? SET p.name = ?, p.modified_at = timestamp() `, personID, lastModified, newName) if err != nil { return err } rowsAffected, _ := result.RowsAffected() if rowsAffected == 0 { return errors.New("concurrent modification detected") } return nil } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881939411982-tab-1" role="tabpanel" aria-labelledby="tabs-1774880881939411982-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">import random import asyncio from datetime import datetime async def update_with_optimistic_locking( client: Client, person_id: int, new_name: str, max_attempts: int = 3 ) -> None: """Update with optimistic concurrency control.""" for attempt in range(max_attempts): async with client.connection() as conn: await conn.begin() try: # Read current version result, _ = await conn.query(""" MATCH (p:Person {id: $id}) RETURN p.version as version """, {"id": person_id}) if not result.rows: await conn.rollback() raise ValueError(f"Person {person_id} not found") current_version = result.rows[0]["version"].as_int # Update with version check await conn.execute(""" MATCH (p:Person {id: $id, version: $version}) SET p.name = $name, p.version = p.version + 1 """, { "id": person_id, "version": current_version, "name": new_name }) # Verify update succeeded check_result, _ = await conn.query(""" MATCH (p:Person {id: $id}) RETURN p.version as version """, {"id": person_id}) new_version = check_result.rows[0]["version"].as_int if new_version != current_version + 1: await conn.rollback() print(f"Optimistic lock conflict, attempt {attempt + 1}") await asyncio.sleep(random.uniform(0.01, 0.1)) continue await conn.commit() return except Exception as e: await conn.rollback() raise raise Exception("Failed after max retry attempts") async def update_with_timestamp( client: Client, person_id: int, new_name: str ) -> None: """Update with timestamp-based optimistic locking.""" async with client.connection() as conn: # Read current timestamp result, _ = await conn.query(""" MATCH (p:Person {id: $id}) RETURN p.modified_at as modified_at """, {"id": person_id}) if not result.rows: raise ValueError(f"Person {person_id} not found") last_modified = result.rows[0]["modified_at"].as_timestamp # Update with timestamp check await conn.execute(""" MATCH (p:Person {id: $id}) WHERE p.modified_at = $modified_at SET p.name = $name, p.modified_at = timestamp() """, { "id": person_id, "modified_at": last_modified, "name": new_name }) # Verify update check_result, _ = await conn.query(""" MATCH (p:Person {id: $id}) RETURN p.modified_at as modified_at """, {"id": person_id}) if check_result.rows[0]["modified_at"].as_timestamp == last_modified: raise Exception("Concurrent modification detected") </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881939411982-tab-2" role="tabpanel" aria-labelledby="tabs-1774880881939411982-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn update_with_optimistic_locking( conn: &mut Connection, person_id: i64, new_name: &str, max_attempts: u32, ) -> Result<(), Box<dyn std::error::Error>> { let mut rng = rand::thread_rng(); for attempt in 0..max_attempts { conn.begin().await?; // Read current version let mut params = HashMap::new(); params.insert("id".to_string(), Value::int(person_id)); let (page, _) = conn.query_with_params( "MATCH (p:Person {id: $id}) RETURN p.version as version", &params ).await?; let current_version = page.rows.first() .and_then(|row| row.get("version")) .and_then(|v| v.as_int().ok()) .ok_or("Person not found")?; // Update with version check params.insert("version".to_string(), Value::int(current_version)); params.insert("name".to_string(), Value::string(new_name)); conn.query_with_params( "MATCH (p:Person {id: $id, version: $version}) SET p.name = $name, p.version = p.version + 1", &params ).await?; // Verify update succeeded let (check_page, _) = conn.query_with_params( "MATCH (p:Person {id: $id}) RETURN p.version as version", &params ).await?; let new_version = check_page.rows.first() .and_then(|row| row.get("version")) .and_then(|v| v.as_int().ok()) .unwrap_or(0); if new_version != current_version + 1 { conn.rollback().await?; println!("Optimistic lock conflict, attempt {}", attempt + 1); sleep(Duration::from_millis(rng.gen_range(10..100))).await; continue; } conn.commit().await?; return Ok(()); } Err("Failed after max retry attempts".into()) } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881939411982-tab-3" role="tabpanel" aria-labelledby="tabs-1774880881939411982-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function updateWithOptimisticLocking( client: GeodeClient, personId: number, newName: string, maxAttempts: number = 3 ): Promise<void> { for (let attempt = 0; attempt < maxAttempts; attempt++) { try { await client.withTransaction(async (tx) => { // Read current version const rows = await tx.queryAll( 'MATCH (p:Person {id: $id}) RETURN p.version as version', { params: { id: personId } } ); if (rows.length === 0) { throw new Error(`Person ${personId} not found`); } const currentVersion = rows[0].get('version')?.asNumber || 0; // Update with version check await tx.exec(` MATCH (p:Person {id: $id, version: $version}) SET p.name = $name, p.version = p.version + 1 `, { params: { id: personId, version: currentVersion, name: newName } }); // Verify update succeeded const checkRows = await tx.queryAll( 'MATCH (p:Person {id: $id}) RETURN p.version as version', { params: { id: personId } } ); const newVersion = checkRows[0]?.get('version')?.asNumber || 0; if (newVersion !== currentVersion + 1) { throw new OptimisticLockError('Concurrent modification detected'); } }); return; // Success } catch (error) { if (error instanceof OptimisticLockError && attempt < maxAttempts - 1) { console.log(`Optimistic lock conflict, attempt ${attempt + 1}`); await new Promise(resolve => setTimeout(resolve, Math.random() * 100) ); continue; } throw error; } } throw new Error('Failed after max retry attempts'); } class OptimisticLockError extends Error { constructor(message: string) { super(message); this.name = 'OptimisticLockError'; } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881939411982-tab-4" role="tabpanel" aria-labelledby="tabs-1774880881939411982-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">const std = @import("std"); const geode = @import("geode_client"); pub fn updateWithOptimisticLocking( client: *geode.GeodeClient, person_id: i64, new_name: []const u8, max_attempts: u32, ) !void { var prng = std.rand.DefaultPrng.init(@intCast(std.time.timestamp())); const random = prng.random(); var attempt: u32 = 0; while (attempt < max_attempts) : (attempt += 1) { try client.sendBegin(); _ = try client.receiveMessage(30000); // Read current version var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("id", .{ .integer = person_id }); try client.sendRunGql(1, "MATCH (p:Person {id: $id}) RETURN p.version as version", .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendPull(1, 1000); const version_result = try client.receiveMessage(30000); defer client.allocator.free(version_result); // Parse current_version from result (simplified) const current_version: i64 = 1; // Would parse from JSON // Update with version check params.clearRetainingCapacity(); try params.put("id", .{ .integer = person_id }); try params.put("version", .{ .integer = current_version }); try params.put("name", .{ .string = new_name }); client.sendRunGql(2, \\MATCH (p:Person {id: $id, version: $version}) \\SET p.name = $name, p.version = p.version + 1 , .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Verify update succeeded (simplified - would check actual result) const update_succeeded = true; if (!update_succeeded) { try client.sendRollback(); _ = try client.receiveMessage(30000); std.debug.print("Optimistic lock conflict, attempt {d}\n", .{attempt + 1}); const delay_ms = random.intRangeAtMost(u64, 10, 100); std.time.sleep(delay_ms * std.time.ns_per_ms); continue; } try client.sendCommit(); _ = try client.receiveMessage(30000); return; } return error.MaxRetriesExceeded; } </code></pre></div> </div></div> </div> <h4 id="pessimistic-concurrency-control" class="position-relative d-flex align-items-center group"> Pessimistic Concurrency Control <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="pessimistic-concurrency-control" aria-haspopup="dialog" aria-label="Share link: Pessimistic Concurrency Control"> Share link </button> </h4>Acquire locks before reading. Prevents conflicts at the cost of reduced concurrency. <div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880881998507498" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880881998507498-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881998507498-tab-0" type="button" role="tab" aria-controls="tabs-1774880881998507498-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881998507498-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881998507498-tab-1" type="button" role="tab" aria-controls="tabs-1774880881998507498-tab-1" aria-selected="false" > Python </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881998507498-tab-2-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881998507498-tab-2" type="button" role="tab" aria-controls="tabs-1774880881998507498-tab-2" aria-selected="false" > Rust </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881998507498-tab-3-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881998507498-tab-3" type="button" role="tab" aria-controls="tabs-1774880881998507498-tab-3" aria-selected="false" > Node.js </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880881998507498-tab-4-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880881998507498-tab-4" type="button" role="tab" aria-controls="tabs-1774880881998507498-tab-4" aria-selected="false" > Zig </button> </li></ul> <div class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880881998507498-content"><div class="tab-pane fade show active" id="tabs-1774880881998507498-tab-0" role="tabpanel" aria-labelledby="tabs-1774880881998507498-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Pessimistic locking with SELECT FOR UPDATE func updateWithPessimisticLocking(db *sql.DB, personID int, newName string) error { ctx := context.Background() tx, err := db.BeginTx(ctx, &sql.TxOptions{ Isolation: sql.LevelSerializable, }) if err != nil { return err } defer tx.Rollback() // Lock the row for update var currentName string err = tx.QueryRowContext(ctx, ` MATCH (p:Person {id: ?}) SET p._lock = true RETURN p.name `, personID).Scan(&currentName) if err != nil { return err } // Perform update (row is locked) _, err = tx.ExecContext(ctx, ` MATCH (p:Person {id: ?}) SET p.name = ? REMOVE p._lock `, personID, newName) if err != nil { return err } return tx.Commit() } // Using Geode's built-in locking func updateWithExplicitLock(db *sql.DB, accountID int, amount float64) error { ctx := context.Background() tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer tx.Rollback() // Acquire exclusive lock _, err = tx.ExecContext(ctx, ` CALL geode.locks.acquire('account_' + ?, 'EXCLUSIVE', 30000) `, accountID) if err != nil { return fmt.Errorf("failed to acquire lock: %w", err) } // Perform update _, err = tx.ExecContext(ctx, ` MATCH (a:Account {id: ?}) SET a.balance = a.balance + ? `, accountID, amount) if err != nil { return err } // Lock is automatically released on commit/rollback return tx.Commit() } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881998507498-tab-1" role="tabpanel" aria-labelledby="tabs-1774880881998507498-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async def update_with_pessimistic_locking( client: Client, person_id: int, new_name: str ) -> None: """Update with pessimistic locking.""" async with client.connection() as conn: await conn.begin(isolation_level="serializable") try: # Lock the row for update result, _ = await conn.query(""" MATCH (p:Person {id: $id}) SET p._lock = true RETURN p.name as name """, {"id": person_id}) if not result.rows: raise ValueError(f"Person {person_id} not found") # Perform update (row is locked) await conn.execute(""" MATCH (p:Person {id: $id}) SET p.name = $name REMOVE p._lock """, {"id": person_id, "name": new_name}) await conn.commit() except Exception: await conn.rollback() raise async def update_with_explicit_lock( client: Client, account_id: int, amount: float, lock_timeout_ms: int = 30000 ) -> None: """Update with explicit lock acquisition.""" async with client.connection() as conn: await conn.begin() try: # Acquire exclusive lock await conn.execute(""" CALL geode.locks.acquire($lock_key, 'EXCLUSIVE', $timeout) """, { "lock_key": f"account_{account_id}", "timeout": lock_timeout_ms }) # Perform update await conn.execute(""" MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount """, {"id": account_id, "amount": amount}) # Lock is automatically released on commit await conn.commit() except Exception: await conn.rollback() raise # Lock context manager class ExclusiveLock: def __init__(self, conn, lock_key: str, timeout_ms: int = 30000): self.conn = conn self.lock_key = lock_key self.timeout_ms = timeout_ms async def __aenter__(self): await self.conn.execute(""" CALL geode.locks.acquire($key, 'EXCLUSIVE', $timeout) """, {"key": self.lock_key, "timeout": self.timeout_ms}) return self async def __aexit__(self, exc_type, exc_val, exc_tb): # Lock released automatically by transaction pass # Usage async def transfer_with_locks( client: Client, from_account: int, to_account: int, amount: float ) -> None: async with client.connection() as conn: await conn.begin() # Acquire locks in consistent order to prevent deadlocks lock_keys = sorted([f"account_{from_account}", f"account_{to_account}"]) try: for key in lock_keys: async with ExclusiveLock(conn, key): pass # Lock acquired # Perform transfer await conn.execute(""" MATCH (a:Account {id: $id}) SET a.balance = a.balance - $amount """, {"id": from_account, "amount": amount}) await conn.execute(""" MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount """, {"id": to_account, "amount": amount}) await conn.commit() except Exception: await conn.rollback() raise </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881998507498-tab-2" role="tabpanel" aria-labelledby="tabs-1774880881998507498-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn update_with_pessimistic_locking( conn: &mut Connection, person_id: i64, new_name: &str, ) -> Result<(), Error> { // Start with serializable isolation let options = TransactionOptions { isolation_level: IsolationLevel::Serializable, read_only: false, }; conn.begin_with_options(options).await?; // Lock the row for update let mut params = HashMap::new(); params.insert("id".to_string(), Value::int(person_id)); let (page, _) = conn.query_with_params( "MATCH (p:Person {id: $id}) SET p._lock = true RETURN p.name as name", &params ).await?; if page.rows.is_empty() { conn.rollback().await?; return Err(Error::new("Person not found")); } // Perform update (row is locked) params.insert("name".to_string(), Value::string(new_name)); conn.query_with_params( "MATCH (p:Person {id: $id}) SET p.name = $name REMOVE p._lock", &params ).await?; conn.commit().await?; Ok(()) } async fn update_with_explicit_lock( conn: &mut Connection, account_id: i64, amount: f64, ) -> Result<(), Error> { conn.begin().await?; // Acquire exclusive lock let mut params = HashMap::new(); params.insert("lock_key".to_string(), Value::string(&format!("account_{}", account_id))); params.insert("timeout".to_string(), Value::int(30000)); conn.query_with_params( "CALL geode.locks.acquire($lock_key, 'EXCLUSIVE', $timeout)", &params ).await?; // Perform update params.insert("id".to_string(), Value::int(account_id)); params.insert("amount".to_string(), Value::float(amount)); conn.query_with_params( "MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount", &params ).await?; conn.commit().await?; Ok(()) } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881998507498-tab-3" role="tabpanel" aria-labelledby="tabs-1774880881998507498-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function updateWithPessimisticLocking( client: GeodeClient, personId: number, newName: string ): Promise<void> { await client.withTransaction( async (tx) => { // Lock the row for update const rows = await tx.queryAll( 'MATCH (p:Person {id: $id}) SET p._lock = true RETURN p.name as name', { params: { id: personId } } ); if (rows.length === 0) { throw new Error(`Person ${personId} not found`); } // Perform update (row is locked) await tx.exec( 'MATCH (p:Person {id: $id}) SET p.name = $name REMOVE p._lock', { params: { id: personId, name: newName } } ); }, { isolationLevel: 'serializable' } ); } async function updateWithExplicitLock( client: GeodeClient, accountId: number, amount: number ): Promise<void> { await client.withTransaction(async (tx) => { // Acquire exclusive lock await tx.exec( 'CALL geode.locks.acquire($lockKey, \'EXCLUSIVE\', $timeout)', { params: { lockKey: `account_${accountId}`, timeout: 30000 } } ); // Perform update await tx.exec( 'MATCH (a:Account {id: $id}) SET a.balance = a.balance + $amount', { params: { id: accountId, amount } } ); // Lock released automatically on commit }); } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880881998507498-tab-4" role="tabpanel" aria-labelledby="tabs-1774880881998507498-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">pub fn updateWithPessimisticLocking( client: *geode.GeodeClient, person_id: i64, new_name: []const u8, ) !void { // Start with serializable isolation try client.sendRunGql(1, "BEGIN ISOLATION LEVEL SERIALIZABLE", null); _ = try client.receiveMessage(30000); var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("id", .{ .integer = person_id }); // Lock the row for update client.sendRunGql(2, "MATCH (p:Person {id: $id}) SET p._lock = true RETURN p.name as name", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); // Perform update (row is locked) params.clearRetainingCapacity(); try params.put("id", .{ .integer = person_id }); try params.put("name", .{ .string = new_name }); client.sendRunGql(3, "MATCH (p:Person {id: $id}) SET p.name = $name REMOVE p._lock", .{ .object = params }) catch |e| { try client.sendRollback(); _ = try client.receiveMessage(30000); return e; }; _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); } </code></pre></div> </div></div> </div> <h3 id="deadlock-detection-and-prevention" class="position-relative d-flex align-items-center group"> Deadlock Detection and Prevention <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="deadlock-detection-and-prevention" aria-haspopup="dialog" aria-label="Share link: Deadlock Detection and Prevention"> Share link </button> </h3> <h4 id="deadlock-prevention-strategies" class="position-relative d-flex align-items-center group"> Deadlock Prevention Strategies <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="deadlock-prevention-strategies" aria-haspopup="dialog" aria-label="Share link: Deadlock Prevention Strategies"> Share link </button> </h4><ol> <li>Lock ordering: Always acquire locks in a consistent order</li> <li>Timeout-based: Use lock timeouts to break deadlocks</li> <li>Deadlock detection: Let the database detect and resolve deadlocks</li> </ol> <div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880882049339802" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880882049339802-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880882049339802-tab-0" type="button" role="tab" aria-controls="tabs-1774880882049339802-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880882049339802-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880882049339802-tab-1" type="button" 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class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880882049339802-content"><div class="tab-pane fade show active" id="tabs-1774880882049339802-tab-0" role="tabpanel" aria-labelledby="tabs-1774880882049339802-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Lock ordering to prevent deadlocks func transferWithLockOrdering(db *sql.DB, fromID, toID int, amount float64) error { ctx := context.Background() // Always lock in ascending ID order firstID, secondID := fromID, toID if fromID > toID { firstID, secondID = toID, fromID } tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer tx.Rollback() // Lock first account _, err = tx.ExecContext(ctx, ` MATCH (a:Account {id: ?}) SET a._lock = true `, firstID) if err != nil { return err } // Lock second account _, err = tx.ExecContext(ctx, ` MATCH (a:Account {id: ?}) SET a._lock = true `, secondID) if err != nil { return err } // Perform transfer _, err = tx.ExecContext(ctx, ` MATCH (from:Account {id: ?}), (to:Account {id: ?}) SET from.balance = from.balance - ?, to.balance = to.balance + ? `, fromID, toID, amount, amount) if err != nil { return err } // Remove locks _, _ = tx.ExecContext(ctx, ` MATCH (a:Account) WHERE a.id IN [?, ?] REMOVE a._lock `, firstID, secondID) return tx.Commit() } // Deadlock retry with exponential backoff func executeWithDeadlockRetry(db *sql.DB, maxRetries int, fn func(*sql.Tx) error) error { for attempt := 1; attempt <= maxRetries; attempt++ { tx, err := db.BeginTx(context.Background(), nil) if err != nil { return err } err = fn(tx) if err != nil { tx.Rollback() // Check for deadlock var geodeErr *geode.Error if errors.As(err, &geodeErr) && geodeErr.Code == "GQL-05003" { log.Printf("Deadlock detected, attempt %d/%d", attempt, maxRetries) time.Sleep(time.Duration(rand.Intn(100)*attempt) * time.Millisecond) continue } return err } if err := tx.Commit(); err != nil { return err } return nil } return errors.New("max deadlock retries exceeded") } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882049339802-tab-1" role="tabpanel" aria-labelledby="tabs-1774880882049339802-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async def transfer_with_lock_ordering( client: Client, from_id: int, to_id: int, amount: float ) -> None: """Transfer with consistent lock ordering to prevent deadlocks.""" # Always lock in ascending ID order first_id, second_id = sorted([from_id, to_id]) async with client.connection() as conn: await conn.begin() try: # Lock first account await conn.execute(""" MATCH (a:Account {id: $id}) SET a._lock = true """, {"id": first_id}) # Lock second account await conn.execute(""" MATCH (a:Account {id: $id}) SET a._lock = true """, {"id": second_id}) # Perform transfer await conn.execute(""" MATCH (from:Account {id: $from_id}), (to:Account {id: $to_id}) SET from.balance = from.balance - $amount, to.balance = to.balance + $amount """, {"from_id": from_id, "to_id": to_id, "amount": amount}) # Remove locks await conn.execute(""" MATCH (a:Account) WHERE a.id IN [$first, $second] REMOVE a._lock """, {"first": first_id, "second": second_id}) await conn.commit() except Exception: await conn.rollback() raise async def execute_with_deadlock_retry( client: Client, max_retries: int, operation: Callable[[Any], Awaitable[None]] ) -> None: """Execute with automatic deadlock retry.""" for attempt in range(1, max_retries + 1): async with client.connection() as conn: await conn.begin() try: await operation(conn) await conn.commit() return except GeodeError as e: await conn.rollback() if e.code == "GQL-05003": # Deadlock print(f"Deadlock detected, attempt {attempt}/{max_retries}") await asyncio.sleep(random.uniform(0.01, 0.1) * attempt) continue raise raise Exception("Max deadlock retries exceeded") # Usage async def main(): client = Client(host="localhost", port=3141, skip_verify=True) await execute_with_deadlock_retry(client, 3, async def inner(conn): await conn.execute("MATCH (a:Account {id: 1}) SET a.balance = a.balance - 100") await conn.execute("MATCH (a:Account {id: 2}) SET a.balance = a.balance + 100") ) </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882049339802-tab-2" role="tabpanel" aria-labelledby="tabs-1774880882049339802-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn transfer_with_lock_ordering( conn: &mut Connection, from_id: i64, to_id: i64, amount: f64, ) -> Result<(), Error> { // Always lock in ascending ID order let (first_id, second_id) = if from_id < to_id { (from_id, to_id) } else { (to_id, from_id) }; conn.begin().await?; // Lock first account let mut params = HashMap::new(); params.insert("id".to_string(), Value::int(first_id)); conn.query_with_params( "MATCH (a:Account {id: $id}) SET a._lock = true", &params ).await?; // Lock second account params.insert("id".to_string(), Value::int(second_id)); conn.query_with_params( "MATCH (a:Account {id: $id}) SET a._lock = true", &params ).await?; // Perform transfer params.insert("from_id".to_string(), Value::int(from_id)); params.insert("to_id".to_string(), Value::int(to_id)); params.insert("amount".to_string(), Value::float(amount)); conn.query_with_params(r#" MATCH (from:Account {id: $from_id}), (to:Account {id: $to_id}) SET from.balance = from.balance - $amount, to.balance = to.balance + $amount "#, &params).await?; // Remove locks params.insert("first".to_string(), Value::int(first_id)); params.insert("second".to_string(), Value::int(second_id)); conn.query_with_params( "MATCH (a:Account) WHERE a.id IN [$first, $second] REMOVE a._lock", &params ).await?; conn.commit().await?; Ok(()) } async fn execute_with_deadlock_retry<F, Fut>( conn: &mut Connection, max_retries: u32, operation: F, ) -> Result<(), Error> where F: Fn(&mut Connection) -> Fut, Fut: std::future::Future<Output = Result<(), Error>>, { let mut rng = rand::thread_rng(); for attempt in 1..=max_retries { conn.begin().await?; match operation(conn).await { Ok(_) => { conn.commit().await?; return Ok(()); } Err(e) if e.code() == Some(ErrorCode::DeadlockDetected) => { conn.rollback().await?; println!("Deadlock detected, attempt {}/{}", attempt, max_retries); let delay = Duration::from_millis(rng.gen_range(10..100) * attempt as u64); sleep(delay).await; } Err(e) => { conn.rollback().await?; return Err(e); } } } Err(Error::new("Max deadlock retries exceeded")) } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882049339802-tab-3" role="tabpanel" aria-labelledby="tabs-1774880882049339802-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function transferWithLockOrdering( client: GeodeClient, fromId: number, toId: number, amount: number ): Promise<void> { // Always lock in ascending ID order const [firstId, secondId] = [fromId, toId].sort((a, b) => a - b); await client.withTransaction(async (tx) => { // Lock first account await tx.exec( 'MATCH (a:Account {id: $id}) SET a._lock = true', { params: { id: firstId } } ); // Lock second account await tx.exec( 'MATCH (a:Account {id: $id}) SET a._lock = true', { params: { id: secondId } } ); // Perform transfer await tx.exec(` MATCH (from:Account {id: $fromId}), (to:Account {id: $toId}) SET from.balance = from.balance - $amount, to.balance = to.balance + $amount `, { params: { fromId, toId, amount } }); // Remove locks await tx.exec( 'MATCH (a:Account) WHERE a.id IN [$first, $second] REMOVE a._lock', { params: { first: firstId, second: secondId } } ); }); } async function executeWithDeadlockRetry<T>( client: GeodeClient, maxRetries: number, operation: (tx: Transaction) => Promise<T> ): Promise<T> { for (let attempt = 1; attempt <= maxRetries; attempt++) { try { return await client.withTransaction(operation); } catch (error) { if (error instanceof GeodeError && error.code === 'GQL-05003') { console.log(`Deadlock detected, attempt ${attempt}/${maxRetries}`); await new Promise(resolve => setTimeout(resolve, Math.random() * 100 * attempt) ); continue; } throw error; } } throw new Error('Max deadlock retries exceeded'); } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882049339802-tab-4" role="tabpanel" aria-labelledby="tabs-1774880882049339802-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">pub fn transferWithLockOrdering( client: *geode.GeodeClient, from_id: i64, to_id: i64, amount: f64, ) !void { // Always lock in ascending ID order const first_id = @min(from_id, to_id); const second_id = @max(from_id, to_id); try client.sendBegin(); _ = try client.receiveMessage(30000); var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); // Lock first account try params.put("id", .{ .integer = first_id }); try client.sendRunGql(1, "MATCH (a:Account {id: $id}) SET a._lock = true", .{ .object = params }); _ = try client.receiveMessage(30000); // Lock second account params.clearRetainingCapacity(); try params.put("id", .{ .integer = second_id }); try client.sendRunGql(2, "MATCH (a:Account {id: $id}) SET a._lock = true", .{ .object = params }); _ = try client.receiveMessage(30000); // Perform transfer params.clearRetainingCapacity(); try params.put("from_id", .{ .integer = from_id }); try params.put("to_id", .{ .integer = to_id }); try params.put("amount", .{ .float = amount }); try client.sendRunGql(3, \\MATCH (from:Account {id: $from_id}), (to:Account {id: $to_id}) \\SET from.balance = from.balance - $amount, \\ to.balance = to.balance + $amount , .{ .object = params }); _ = try client.receiveMessage(30000); // Remove locks params.clearRetainingCapacity(); try params.put("first", .{ .integer = first_id }); try params.put("second", .{ .integer = second_id }); try client.sendRunGql(4, "MATCH (a:Account) WHERE a.id IN [$first, $second] REMOVE a._lock", .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); } </code></pre></div> </div></div> </div> <h3 id="long-running-transactions" class="position-relative d-flex align-items-center group"> Long-Running Transactions <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="long-running-transactions" aria-haspopup="dialog" aria-label="Share link: Long-Running Transactions"> Share link </button> </h3>Handle transactions that may take a long time to complete. <h4 id="best-practices" class="position-relative d-flex align-items-center group"> Best Practices <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="best-practices" aria-haspopup="dialog" aria-label="Share link: Best Practices"> Share link </button> </h4><ol> <li>Break into smaller transactions: Process data in batches</li> <li>Use progress tracking: Allow resumption after failure</li> <li>Set appropriate timeouts: Prevent resource exhaustion</li> <li>Monitor transaction duration: Alert on long-running transactions</li> </ol> <div class="docs-tabs mb-4"> <ul class="nav nav-tabs" id="tabs-1774880882096894496" role="tablist"><li class="nav-item" role="presentation"> <button class="nav-link active" id="tabs-1774880882096894496-tab-0-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880882096894496-tab-0" type="button" role="tab" aria-controls="tabs-1774880882096894496-tab-0" aria-selected="true" > Go </button> </li><li class="nav-item" role="presentation"> <button class="nav-link" id="tabs-1774880882096894496-tab-1-tab" data-bs-toggle="tab" data-bs-target="#tabs-1774880882096894496-tab-1" type="button" role="tab" 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class="tab-content border border-top-0 rounded-bottom p-3" id="tabs-1774880882096894496-content"><div class="tab-pane fade show active" id="tabs-1774880882096894496-tab-0" role="tabpanel" aria-labelledby="tabs-1774880882096894496-tab-0-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-go" data-lang="go">// Batch processing with progress tracking func processBatch(db *sql.DB, batchSize int) error { ctx := context.Background() // Get last processed ID var lastProcessedID int _ = db.QueryRowContext(ctx, ` MATCH (p:Progress {name: 'migration'}) RETURN p.last_id `).Scan(&lastProcessedID) for { tx, err := db.BeginTx(ctx, nil) if err != nil { return err } // Process batch rows, err := tx.QueryContext(ctx, ` MATCH (n:OldData) WHERE n.id > ? WITH n ORDER BY n.id LIMIT ? SET n:ProcessedData RETURN max(n.id) as max_id, count(n) as processed `, lastProcessedID, batchSize) if err != nil { tx.Rollback() return err } var maxID, processed int if rows.Next() { rows.Scan(&maxID, &processed) } rows.Close() if processed == 0 { tx.Rollback() break // No more data } // Update progress _, err = tx.ExecContext(ctx, ` MERGE (p:Progress {name: 'migration'}) SET p.last_id = ?, p.updated_at = timestamp() `, maxID) if err != nil { tx.Rollback() return err } if err := tx.Commit(); err != nil { return err } lastProcessedID = maxID log.Printf("Processed %d records, last ID: %d", processed, maxID) } return nil } // Transaction timeout func executeWithTimeout(db *sql.DB, timeout time.Duration) error { ctx, cancel := context.WithTimeout(context.Background(), timeout) defer cancel() tx, err := db.BeginTx(ctx, nil) if err != nil { return err } defer tx.Rollback() // Long-running operation _, err = tx.ExecContext(ctx, ` MATCH (n:Data) SET n.processed = true `) if err != nil { if ctx.Err() == context.DeadlineExceeded { return errors.New("transaction timeout exceeded") } return err } return tx.Commit() } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882096894496-tab-1" role="tabpanel" aria-labelledby="tabs-1774880882096894496-tab-1-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python">async def process_batch( client: Client, batch_size: int = 1000 ) -> None: """Process data in batches with progress tracking.""" # Get last processed ID async with client.connection() as conn: result, _ = await conn.query(""" MATCH (p:Progress {name: 'migration'}) RETURN p.last_id as last_id """) last_processed_id = ( result.rows[0]["last_id"].as_int if result.rows else 0 ) while True: async with client.connection() as conn: await conn.begin() try: # Process batch result, _ = await conn.query(""" MATCH (n:OldData) WHERE n.id > $last_id WITH n ORDER BY n.id LIMIT $batch_size SET n:ProcessedData RETURN max(n.id) as max_id, count(n) as processed """, {"last_id": last_processed_id, "batch_size": batch_size}) if not result.rows: await conn.rollback() break max_id = result.rows[0]["max_id"].as_int processed = result.rows[0]["processed"].as_int if processed == 0: await conn.rollback() break # Update progress await conn.execute(""" MERGE (p:Progress {name: 'migration'}) SET p.last_id = $max_id, p.updated_at = timestamp() """, {"max_id": max_id}) await conn.commit() last_processed_id = max_id print(f"Processed {processed} records, last ID: {max_id}") except Exception: await conn.rollback() raise async def execute_with_timeout( client: Client, timeout_seconds: float ) -> None: """Execute with timeout.""" async with client.connection() as conn: await conn.begin() try: # Set query timeout await asyncio.wait_for( conn.execute(""" MATCH (n:Data) SET n.processed = true """), timeout=timeout_seconds ) await conn.commit() except asyncio.TimeoutError: await conn.rollback() raise TimeoutError("Transaction timeout exceeded") except Exception: await conn.rollback() raise </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882096894496-tab-2" role="tabpanel" aria-labelledby="tabs-1774880882096894496-tab-2-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-rust" data-lang="rust">async fn process_batch( conn: &mut Connection, batch_size: i64, ) -> Result<(), Error> { // Get last processed ID let (page, _) = conn.query( "MATCH (p:Progress {name: 'migration'}) RETURN p.last_id as last_id" ).await?; let mut last_processed_id = page.rows.first() .and_then(|row| row.get("last_id")) .and_then(|v| v.as_int().ok()) .unwrap_or(0); loop { conn.begin().await?; let mut params = HashMap::new(); params.insert("last_id".to_string(), Value::int(last_processed_id)); params.insert("batch_size".to_string(), Value::int(batch_size)); let (page, _) = conn.query_with_params(r#" MATCH (n:OldData) WHERE n.id > $last_id WITH n ORDER BY n.id LIMIT $batch_size SET n:ProcessedData RETURN max(n.id) as max_id, count(n) as processed "#, &params).await?; let max_id = page.rows.first() .and_then(|row| row.get("max_id")) .and_then(|v| v.as_int().ok()) .unwrap_or(0); let processed = page.rows.first() .and_then(|row| row.get("processed")) .and_then(|v| v.as_int().ok()) .unwrap_or(0); if processed == 0 { conn.rollback().await?; break; } // Update progress params.insert("max_id".to_string(), Value::int(max_id)); conn.query_with_params(r#" MERGE (p:Progress {name: 'migration'}) SET p.last_id = $max_id, p.updated_at = timestamp() "#, &params).await?; conn.commit().await?; last_processed_id = max_id; println!("Processed {} records, last ID: {}", processed, max_id); } Ok(()) } async fn execute_with_timeout( conn: &mut Connection, timeout: Duration, ) -> Result<(), Error> { conn.begin().await?; match tokio::time::timeout(timeout, async { conn.query("MATCH (n:Data) SET n.processed = true").await }).await { Ok(result) => { result?; conn.commit().await?; Ok(()) } Err(_) => { conn.rollback().await?; Err(Error::new("Transaction timeout exceeded")) } } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882096894496-tab-3" role="tabpanel" aria-labelledby="tabs-1774880882096894496-tab-3-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-typescript" data-lang="typescript">async function processBatch( client: GeodeClient, batchSize: number = 1000 ): Promise<void> { // Get last processed ID let lastProcessedId = 0; const initRows = await client.queryAll( 'MATCH (p:Progress {name: \'migration\'}) RETURN p.last_id as last_id' ); if (initRows.length > 0) { lastProcessedId = initRows[0].get('last_id')?.asNumber || 0; } while (true) { await client.withTransaction(async (tx) => { // Process batch const rows = await tx.queryAll(` MATCH (n:OldData) WHERE n.id > $lastId WITH n ORDER BY n.id LIMIT $batchSize SET n:ProcessedData RETURN max(n.id) as maxId, count(n) as processed `, { params: { lastId: lastProcessedId, batchSize } }); if (rows.length === 0) { throw new BatchComplete(); } const maxId = rows[0].get('maxId')?.asNumber || 0; const processed = rows[0].get('processed')?.asNumber || 0; if (processed === 0) { throw new BatchComplete(); } // Update progress await tx.exec(` MERGE (p:Progress {name: 'migration'}) SET p.last_id = $maxId, p.updated_at = timestamp() `, { params: { maxId } }); lastProcessedId = maxId; console.log(`Processed ${processed} records, last ID: ${maxId}`); }); } } class BatchComplete extends Error { constructor() { super('Batch processing complete'); this.name = 'BatchComplete'; } } async function executeWithTimeout( client: GeodeClient, timeoutMs: number ): Promise<void> { const controller = new AbortController(); const timeoutId = setTimeout(() => controller.abort(), timeoutMs); try { await client.withTransaction(async (tx) => { await tx.exec('MATCH (n:Data) SET n.processed = true', { signal: controller.signal }); }); } catch (error) { if (controller.signal.aborted) { throw new Error('Transaction timeout exceeded'); } throw error; } finally { clearTimeout(timeoutId); } } </code></pre></div> </div><div class="tab-pane fade" id="tabs-1774880882096894496-tab-4" role="tabpanel" aria-labelledby="tabs-1774880882096894496-tab-4-tab" > <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig">pub fn processBatch( client: *geode.GeodeClient, batch_size: i64, ) !void { // Get last processed ID try client.sendRunGql(1, "MATCH (p:Progress {name: 'migration'}) RETURN p.last_id as last_id", null); _ = try client.receiveMessage(30000); try client.sendPull(1, 1000); const init_result = try client.receiveMessage(30000); defer client.allocator.free(init_result); var last_processed_id: i64 = 0; // Would parse from init_result while (true) { try client.sendBegin(); _ = try client.receiveMessage(30000); var params = std.json.ObjectMap.init(client.allocator); defer params.deinit(); try params.put("last_id", .{ .integer = last_processed_id }); try params.put("batch_size", .{ .integer = batch_size }); try client.sendRunGql(2, \\MATCH (n:OldData) \\WHERE n.id > $last_id \\WITH n ORDER BY n.id LIMIT $batch_size \\SET n:ProcessedData \\RETURN max(n.id) as max_id, count(n) as processed , .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendPull(2, 1000); const batch_result = try client.receiveMessage(30000); defer client.allocator.free(batch_result); // Parse max_id and processed from result (simplified) const max_id: i64 = 0; const processed: i64 = 0; if (processed == 0) { try client.sendRollback(); _ = try client.receiveMessage(30000); break; } // Update progress params.clearRetainingCapacity(); try params.put("max_id", .{ .integer = max_id }); try client.sendRunGql(3, \\MERGE (p:Progress {name: 'migration'}) \\SET p.last_id = $max_id, p.updated_at = timestamp() , .{ .object = params }); _ = try client.receiveMessage(30000); try client.sendCommit(); _ = try client.receiveMessage(30000); last_processed_id = max_id; std.debug.print("Processed {d} records, last ID: {d}\n", .{ processed, max_id }); } } </code></pre></div> </div></div> </div> <h3 id="best-practices-summary" class="position-relative d-flex align-items-center group"> Best Practices Summary <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="best-practices-summary" aria-haspopup="dialog" aria-label="Share link: Best Practices Summary"> Share link </button> </h3> <h4 id="do" class="position-relative d-flex align-items-center group"> Do <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="do" aria-haspopup="dialog" aria-label="Share link: Do"> Share link </button> </h4><ul> <li>Use appropriate isolation levels for your use case</li> <li>Implement retry logic for transient errors (deadlocks, serialization failures)</li> <li>Use savepoints for partial rollback in complex transactions</li> <li>Acquire locks in consistent order to prevent deadlocks</li> <li>Break long-running operations into smaller batches</li> <li>Set appropriate timeouts</li> <li>Log transaction boundaries and durations</li> </ul> <h4 id="avoid" class="position-relative d-flex align-items-center group"> Avoid <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="avoid" aria-haspopup="dialog" aria-label="Share link: Avoid"> Share link </button> </h4><ul> <li>Holding transactions open longer than necessary</li> <li>Mixing read-only and write operations without purpose</li> <li>Using higher isolation levels than needed</li> <li>Ignoring deadlock detection</li> <li>Creating very large transactions</li> </ul> <h3 id="resources" class="position-relative d-flex align-items-center group"> Resources <button type="button" class="h-share btn btn-link p-0 text-decoration-none link-secondary opacity-50 hover-opacity-100 transition-all ms-1" data-share-target="resources" aria-haspopup="dialog" aria-label="Share link: Resources"> Share link </button> </h3><ul> <li><a href="/guides/error-handling/" >Error Handling Guide</a> </li> <li><a href="/guides/testing/" >Testing Strategies Guide</a> </li> <li><a href="/docs/performance/" >Performance Guide</a> </li> <li><a href="/docs/gql-reference/" >GQL Reference</a> </li> </ul> <hr> Questions? Discuss transaction management in our <a href="https://forum.geodedb.com" aria-label="forum – opens in new window" target="_blank" rel="noopener noreferrer" >forum ↗ </a> .

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