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<span>System Architecture &amp; Design</span>
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</script><p>The <strong>System Architecture & Design</strong> category provides comprehensive documentation of Geode’s internal architecture, implementation decisions, and design principles. Understanding Geode’s architecture enables effective performance optimization, informed troubleshooting, strategic deployment decisions, and contributions to the codebase. From the QUIC wire protocol through query execution and storage management, these resources explain how Geode implements a production-ready graph database.</p>
<h3 id="overview" class="position-relative d-flex align-items-center group">
<span>Overview</span>
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</h3><p>Geode’s architecture reflects careful design choices prioritizing <strong>correctness</strong>, <strong>performance</strong>, and <strong>maintainability</strong>. Written in Zig for memory safety and predictable performance, Geode implements a layered architecture with clear separation of concerns:</p>
<p><strong>Wire Protocol Layer</strong>: QUIC-based transport handles encrypted, multiplexed connections</p>
<p><strong>Query Engine</strong>: Parses GQL queries, optimizes execution plans, and coordinates query execution</p>
<p><strong>Transaction Layer</strong>: Provides ACID guarantees using Multi-Version Concurrency Control (MVCC) with Serializable Snapshot Isolation (SSI)</p>
<p><strong>Storage Layer</strong>: Manages persistent data structures including B+trees, Write-Ahead Log (WAL), and memory-mapped files</p>
<p><strong>Index Layer</strong>: Implements specialized indexes including B+tree for properties, HNSW for vector search, and BM25 for full-text search</p>
<p>This layered design enables independent optimization and testing of each component while maintaining clean interfaces between layers.</p>
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<span>Architectural Principles</span>
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<span>Design Philosophy</span>
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</h4><p><strong>Simplicity</strong>: Prefer simple, understandable solutions over complex optimizations. Simple systems are easier to reason about, test, and maintain.</p>
<p><strong>Correctness First</strong>: Ensure correctness before optimization. All optimizations must preserve semantics and maintain ACID guarantees.</p>
<p><strong>Performance by Design</strong>: Design for performance from the start. Retrofitting performance into slow architectures is difficult.</p>
<p><strong>Evidence-Based Development</strong>: All features backed by tests. CANARY markers track requirements and evidence throughout the codebase.</p>
<p><strong>Standards Compliance</strong>: ISO/IEC 39075:2024 compliance ensures portability and predictable behavior.</p>
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<span>Key Architectural Decisions</span>
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</h4><p><strong>Zig Programming Language</strong>: Memory-safe systems programming with predictable performance and no hidden control flow</p>
<p><strong>QUIC-Only Transport</strong>: Eliminate TCP complexity; QUIC provides multiplexing, encryption, and faster connection establishment</p>
<p><strong>MVCC with SSI</strong>: High read concurrency without locks; serializable isolation without performance penalty</p>
<p><strong>Write-Ahead Logging</strong>: Ensure durability with minimal write amplification; sequential writes to append-only log</p>
<p><strong>Cost-Based Optimization</strong>: Query optimizer uses statistics and cost models to choose optimal execution plans</p>
<p><strong>Modular Design</strong>: Clean interfaces between components enable independent development and testing</p>
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<span>System Architecture Documentation</span>
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<span>Core Architecture Guides</span>
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</h4><p><strong><a
href="/docs/architecture/"
>Architecture Overview</a>
</strong>
Entry point for architecture documentation covering all major subsystems and their interactions.</p>
<p><strong><a
href="/docs/architecture/query-execution/"
>Query Execution Architecture</a>
</strong>
Complete query execution pipeline from parsing through result delivery. Covers lexer, parser, optimizer, and executor design.</p>
<p><strong><a
href="/docs/architecture/performance-and-scaling/"
>Performance and Scaling</a>
</strong>
System-level performance architecture including query engine optimization, storage tuning, caching strategies, and distributed scaling.</p>
<p><strong><a
href="/docs/architecture/distributed-architecture/"
>Distributed Architecture</a>
</strong>
Distributed system design including sharding strategies, replication protocols, consistency models, and cross-shard query execution.</p>
<p><strong><a
href="/docs/architecture/wire-protocol/"
>Wire Protocol Specification</a>
</strong>
Complete QUIC-based wire protocol documentation including message formats, connection lifecycle, and error handling.</p>
<p><strong><a
href="/docs/architecture/cli-design/"
>CLI Design</a>
</strong>
Command-line interface architecture including REPL implementation, shell integration, and interactive features.</p>
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<span>Query Engine Architecture</span>
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<span>Lexical Analysis and Parsing</span>
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</h4><p><strong>Lexer</strong>: Tokenizes GQL source into tokens:</p>
<ul>
<li>Keywords (MATCH, WHERE, RETURN)</li>
<li>Identifiers (variable names, labels)</li>
<li>Literals (strings, numbers, booleans)</li>
<li>Operators (comparison, arithmetic, logical)</li>
<li>Punctuation (parentheses, braces, commas)</li>
</ul>
<p><strong>Parser</strong>: Builds Abstract Syntax Tree (AST) from tokens:</p>
<ul>
<li>Recursive descent parsing</li>
<li>Operator precedence handling</li>
<li>Error recovery and reporting</li>
<li>Location tracking for error messages</li>
</ul>
<p><strong>AST</strong>: Structured representation of query:</p>
<ul>
<li>Query clauses (MATCH, WHERE, RETURN)</li>
<li>Patterns (nodes, relationships, paths)</li>
<li>Expressions (comparisons, arithmetic, function calls)</li>
<li>Type information for semantic analysis</li>
</ul>
<h4 id="query-optimization" class="position-relative d-flex align-items-center group">
<span>Query Optimization</span>
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</h4><p><strong>Logical Optimization</strong>: Transforms AST into optimized logical plan:</p>
<ul>
<li>Pattern simplification and normalization</li>
<li>Predicate pushdown (filter early)</li>
<li>Constant folding and expression simplification</li>
<li>Subquery flattening where possible</li>
<li>Common subexpression elimination</li>
</ul>
<p><strong>Cost-Based Optimization</strong>: Chooses execution strategy based on cost estimates:</p>
<ul>
<li>Cardinality estimation using statistics</li>
<li>Index selection based on selectivity</li>
<li>Join order optimization</li>
<li>Join algorithm selection (hash, nested loop, merge)</li>
<li>Parallel execution planning</li>
</ul>
<p><strong>Physical Planning</strong>: Generates executable operator tree:</p>
<ul>
<li>Operator selection (Scan, Seek, Join, Filter, Aggregate)</li>
<li>Memory allocation and buffer sizing</li>
<li>Parallelization and work distribution</li>
<li>Cache-aware execution strategies</li>
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<h4 id="query-execution" class="position-relative d-flex align-items-center group">
<span>Query Execution</span>
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</h4><p><strong>Operator Pipeline</strong>: Query execution as operator pipeline:</p>
<ul>
<li>Pull-based execution (demand-driven)</li>
<li>Volcano-style iterator model</li>
<li>Pipelined execution (no materialization)</li>
<li>Memory-bounded execution</li>
</ul>
<p><strong>Key Operators</strong>:</p>
<ul>
<li><strong>Scan</strong>: Iterate all nodes/relationships</li>
<li><strong>Seek</strong>: Index-based lookup</li>
<li><strong>Filter</strong>: Apply predicates</li>
<li><strong>Join</strong>: Combine patterns (hash, nested loop, merge)</li>
<li><strong>Aggregate</strong>: Grouping and aggregation functions</li>
<li><strong>Sort</strong>: Order results</li>
<li><strong>Limit</strong>: Bound result size</li>
</ul>
<p><strong>Parallelization</strong>:</p>
<ul>
<li>Intra-query parallelism (multiple threads per query)</li>
<li>Inter-query parallelism (multiple concurrent queries)</li>
<li>Parallel scan and aggregate operators</li>
<li>Work-stealing for load balancing</li>
</ul>
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<span>Storage Architecture</span>
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<span>Data Structures</span>
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</h4><p><strong>B+Tree Storage</strong>: Primary storage structure for nodes and relationships:</p>
<ul>
<li>Self-balancing tree ensures O(log n) access</li>
<li>Sequential leaf nodes for range scans</li>
<li>High fan-out reduces tree depth</li>
<li>Copy-on-write for MVCC</li>
</ul>
<p><strong>Write-Ahead Log (WAL)</strong>: Ensures durability:</p>
<ul>
<li>Append-only sequential writes</li>
<li>All mutations logged before applying</li>
<li>Crash recovery replays WAL</li>
<li>Periodic checkpointing reduces replay time</li>
</ul>
<p><strong>Memory-Mapped Files</strong>: Efficient data access:</p>
<ul>
<li>OS manages page cache</li>
<li>Zero-copy reads from cache</li>
<li>Write-back buffering</li>
<li>Large address space utilization</li>
</ul>
<p><strong>Index Structures</strong>:</p>
<ul>
<li><strong>B+tree indexes</strong>: Property and relationship type indexes</li>
<li><strong>HNSW indexes</strong>: Vector similarity search</li>
<li><strong>BM25 indexes</strong>: Full-text search</li>
<li><strong>Hash indexes</strong>: Equality lookups</li>
</ul>
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<span>MVCC and Transaction Management</span>
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</h4><p><strong>Multi-Version Concurrency Control (MVCC)</strong>:</p>
<ul>
<li>Each transaction sees consistent snapshot</li>
<li>Writes create new versions, don’t modify in-place</li>
<li>Readers never block writers</li>
<li>Writers don’t block readers</li>
<li>Garbage collection reclaims old versions</li>
</ul>
<p><strong>Serializable Snapshot Isolation (SSI)</strong>:</p>
<ul>
<li>Strongest isolation level</li>
<li>Prevents all anomalies (dirty read, non-repeatable read, phantom read, write skew)</li>
<li>Implemented via predicate locking and conflict detection</li>
<li>Minimal performance overhead compared to snapshot isolation</li>
</ul>
<p><strong>Transaction Lifecycle</strong>:</p>
<ol>
<li><strong>BEGIN</strong>: Allocate transaction ID, create snapshot</li>
<li><strong>Execute</strong>: Read from snapshot, buffer writes</li>
<li><strong>Validation</strong>: Check for conflicts using SSI</li>
<li><strong>COMMIT</strong>: Write to WAL, apply changes, release locks</li>
<li><strong>ROLLBACK</strong>: Discard buffered writes, release locks</li>
</ol>
<p><strong>Lock Management</strong>:</p>
<ul>
<li>Intent locks for coarse-grained locking</li>
<li>Predicate locks for range queries</li>
<li>Deadlock detection and resolution</li>
<li>Lock escalation for large updates</li>
</ul>
<h4 id="write-ahead-logging-wal" class="position-relative d-flex align-items-center group">
<span>Write-Ahead Logging (WAL)</span>
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</h4><p><strong>WAL Design</strong>:</p>
<ul>
<li>Sequential append-only log</li>
<li>All mutations logged before application</li>
<li>Log entries contain before/after images</li>
<li>Logical logging (operations) not physical (pages)</li>
</ul>
<p><strong>Crash Recovery</strong>:</p>
<ol>
<li>Read WAL from last checkpoint</li>
<li>Redo committed transactions</li>
<li>Undo uncommitted transactions</li>
<li>Restore database to consistent state</li>
</ol>
<p><strong>Checkpointing</strong>:</p>
<ul>
<li>Periodic flush of dirty pages to disk</li>
<li>Creates recovery point in WAL</li>
<li>Truncates WAL to reclaim space</li>
<li>Configurable interval (time or WAL size)</li>
</ul>
<p><strong>Log Shipping</strong>: WAL enables replication:</p>
<ul>
<li>Stream WAL to replicas</li>
<li>Replicas replay log for replication</li>
<li>Asynchronous replication for read replicas</li>
<li>Synchronous replication for high availability</li>
</ul>
<h3 id="network-architecture" class="position-relative d-flex align-items-center group">
<span>Network Architecture</span>
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</h3>
<h4 id="quic-protocol" class="position-relative d-flex align-items-center group">
<span>QUIC Protocol</span>
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</h4><p><strong>Why QUIC Over TCP</strong>:</p>
<ul>
<li><strong>Multiplexing</strong>: Multiple streams without head-of-line blocking</li>
<li><strong>Encryption</strong>: TLS 1.3 built-in, mandatory encryption</li>
<li><strong>Fast connection</strong>: 0-RTT and 1-RTT connection establishment</li>
<li><strong>Connection migration</strong>: Survive network changes</li>
<li><strong>Congestion control</strong>: Modern algorithms (BBR, Cubic)</li>
</ul>
<p><strong>Connection Lifecycle</strong>:</p>
<ol>
<li><strong>Handshake</strong>: TLS 1.3 handshake, negotiate parameters</li>
<li><strong>Streams</strong>: Multiplex requests on single connection</li>
<li><strong>Flow control</strong>: Per-stream and connection-level</li>
<li><strong>Keepalive</strong>: Periodic pings maintain connection</li>
<li><strong>Closure</strong>: Graceful shutdown or idle timeout</li>
</ol>
<p><strong>Stream Management</strong>:</p>
<ul>
<li>Bidirectional streams for request/response</li>
<li>Unidirectional streams for server push</li>
<li>Stream prioritization for multiplexing</li>
<li>Flow control prevents overwhelming receiver</li>
</ul>
<h4 id="wire-protocol" class="position-relative d-flex align-items-center group">
<span>Wire Protocol</span>
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</h4><p><strong>Message Format</strong>: Protobuf wire protocol over QUIC (default) or gRPC.</p>
<p><strong>Client Messages</strong>:</p>
<ul>
<li><code>HelloRequest</code>: initial handshake + authentication</li>
<li><code>ExecuteRequest</code>: execute GQL query with parameters</li>
<li><code>PullRequest</code>: fetch next batch of results</li>
<li><code>BeginRequest</code> / <code>CommitRequest</code> / <code>RollbackRequest</code>: transaction control</li>
<li><code>PingRequest</code>: connection keepalive</li>
</ul>
<p><strong>Server Responses</strong> (via <code>ExecutionResponse</code>):</p>
<ul>
<li><code>SchemaDefinition</code>: query schema (column names, types)</li>
<li><code>DataPage</code>: result rows (batched)</li>
<li><code>Error</code>: error response with ISO status code</li>
<li><code>ExplainPayload</code>: query execution plan</li>
<li><code>ProfilePayload</code>: performance metrics</li>
</ul>
<p><strong>Error Handling</strong>:</p>
<ul>
<li>ISO GQL status codes for errors</li>
<li>Detailed error messages with location</li>
<li>Warnings for non-fatal issues</li>
<li>Partial success for batch operations</li>
</ul>
<h3 id="index-architecture" class="position-relative d-flex align-items-center group">
<span>Index Architecture</span>
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</h3>
<h4 id="btree-indexes" class="position-relative d-flex align-items-center group">
<span>B+Tree Indexes</span>
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</h4><p><strong>Node Property Indexes</strong>:</p>
<ul>
<li>Index on node properties (ID, email, etc.)</li>
<li>Support equality and range queries</li>
<li>Composite indexes for multi-column predicates</li>
<li>Covering indexes include RETURN columns</li>
</ul>
<p><strong>Relationship Type Indexes</strong>:</p>
<ul>
<li>Index relationships by type</li>
<li>Fast lookup of all relationships of given type</li>
<li>Support for relationship property indexes</li>
</ul>
<p><strong>Implementation</strong>:</p>
<ul>
<li>Copy-on-write for MVCC</li>
<li>Bulk loading for efficient creation</li>
<li>Incremental maintenance on updates</li>
<li>Statistics collection for optimizer</li>
</ul>
<h4 id="hnsw-vector-indexes" class="position-relative d-flex align-items-center group">
<span>HNSW Vector Indexes</span>
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</h4><p><strong>Hierarchical Navigable Small World (HNSW)</strong>:</p>
<ul>
<li>Approximate nearest neighbor search</li>
<li>Sublinear search time O(log n)</li>
<li>High recall (>95%) with low latency</li>
<li>Configurable accuracy/performance trade-off</li>
</ul>
<p><strong>Index Structure</strong>:</p>
<ul>
<li>Multi-layer graph structure</li>
<li>Higher layers for coarse navigation</li>
<li>Lower layers for fine-grained search</li>
<li>Configurable layer count and connectivity</li>
</ul>
<p><strong>Distance Metrics</strong>:</p>
<ul>
<li><strong>Cosine similarity</strong>: For normalized embeddings</li>
<li><strong>Euclidean distance</strong>: For Euclidean space</li>
<li><strong>Inner product</strong>: For unnormalized vectors</li>
</ul>
<p><strong>Use Cases</strong>:</p>
<ul>
<li>Semantic search (text embeddings)</li>
<li>Recommendation systems (item embeddings)</li>
<li>Image similarity (vision embeddings)</li>
<li>Anomaly detection (outlier search)</li>
</ul>
<h4 id="bm25-full-text-indexes" class="position-relative d-flex align-items-center group">
<span>BM25 Full-Text Indexes</span>
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</h4><p><strong>BM25 Algorithm</strong>:</p>
<ul>
<li>State-of-the-art text ranking</li>
<li>Term frequency with saturation</li>
<li>Inverse document frequency weighting</li>
<li>Document length normalization</li>
</ul>
<p><strong>Index Structure</strong>:</p>
<ul>
<li>Inverted index (term → documents)</li>
<li>Positional information for phrase queries</li>
<li>Document length statistics</li>
<li>Per-term statistics for IDF</li>
</ul>
<p><strong>Text Processing</strong>:</p>
<ul>
<li>Tokenization (word boundaries)</li>
<li>Lowercasing and normalization</li>
<li>Stopword removal (optional)</li>
<li>Stemming (optional, configurable)</li>
</ul>
<p><strong>Query Features</strong>:</p>
<ul>
<li>Boolean queries (AND, OR, NOT)</li>
<li>Phrase queries (“exact phrase”)</li>
<li>Wildcard queries (prefix matching)</li>
<li>Fuzzy matching (edit distance)</li>
</ul>
<h3 id="concurrency-and-parallelism" class="position-relative d-flex align-items-center group">
<span>Concurrency and Parallelism</span>
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<h4 id="concurrency-control" class="position-relative d-flex align-items-center group">
<span>Concurrency Control</span>
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</h4><p><strong>MVCC Benefits</strong>:</p>
<ul>
<li>Readers never block writers</li>
<li>Writers never block readers</li>
<li>High read concurrency</li>
<li>Predictable performance</li>
</ul>
<p><strong>Isolation Levels</strong>:</p>
<ul>
<li><strong>Serializable (SSI)</strong>: Default, prevents all anomalies</li>
<li><strong>Snapshot Isolation</strong>: Faster but permits write skew</li>
<li><strong>Read Committed</strong>: Weakest, minimal overhead</li>
</ul>
<p><strong>Conflict Detection</strong>:</p>
<ul>
<li>Read-write conflicts (SSI)</li>
<li>Write-write conflicts (all levels)</li>
<li>Predicate conflicts (phantom protection)</li>
<li>Abort conflicting transactions</li>
</ul>
<h4 id="parallelization-strategies" class="position-relative d-flex align-items-center group">
<span>Parallelization Strategies</span>
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</h4><p><strong>Intra-Query Parallelism</strong>:</p>
<ul>
<li>Parallel scans (partition data across threads)</li>
<li>Parallel joins (partition build side)</li>
<li>Parallel aggregations (local then global)</li>
<li>Work-stealing for load balancing</li>
</ul>
<p><strong>Inter-Query Parallelism</strong>:</p>
<ul>
<li>Multiple concurrent queries</li>
<li>Connection pooling</li>
<li>Thread pool for query execution</li>
<li>CPU affinity for cache locality</li>
</ul>
<p><strong>I/O Parallelism</strong>:</p>
<ul>
<li>Asynchronous I/O (io_uring on Linux)</li>
<li>Parallel WAL writes</li>
<li>Parallel checkpoint writes</li>
<li>Prefetching for sequential scans</li>
</ul>
<h3 id="distributed-architecture" class="position-relative d-flex align-items-center group">
<span>Distributed Architecture</span>
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<h4 id="sharding-strategies" class="position-relative d-flex align-items-center group">
<span>Sharding Strategies</span>
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</h4><p><strong>Hash Sharding</strong>: Distribute nodes by hash of ID:</p>
<ul>
<li>Uniform distribution</li>
<li>Simple implementation</li>
<li>No hotspots for random access</li>
<li>Cross-shard queries for traversals</li>
</ul>
<p><strong>Range Sharding</strong>: Distribute nodes by ID range:</p>
<ul>
<li>Locality for sequential IDs</li>
<li>Range queries on single shard</li>
<li>Hotspots for sequential allocation</li>
</ul>
<p><strong>Graph Sharding</strong>: Co-locate connected components:</p>
<ul>
<li>Minimize cross-shard traversals</li>
<li>Complex partitioning</li>
<li>Rebalancing overhead</li>
<li>Best for community-structured graphs</li>
</ul>
<h4 id="replication" class="position-relative d-flex align-items-center group">
<span>Replication</span>
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</h4><p><strong>Read Replicas</strong>:</p>
<ul>
<li>WAL shipping to replicas</li>
<li>Eventually consistent reads</li>
<li>Scale read throughput</li>
<li>Failover for high availability</li>
</ul>
<p><strong>Synchronous Replication</strong>:</p>
<ul>
<li>Strong consistency</li>
<li>Higher latency (wait for replica ACK)</li>
<li>Data durability across nodes</li>
</ul>
<p><strong>Asynchronous Replication</strong>:</p>
<ul>
<li>Lower latency (don’t wait for replica)</li>
<li>Eventual consistency</li>
<li>Risk of data loss on primary failure</li>
</ul>
<h4 id="distributed-query-execution" class="position-relative d-flex align-items-center group">
<span>Distributed Query Execution</span>
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</h4><p><strong>Cross-Shard Queries</strong>:</p>
<ul>
<li>Query coordinator on client node</li>
<li>Ship subqueries to relevant shards</li>
<li>Gather and merge results</li>
<li>Distributed joins and aggregations</li>
</ul>
<p><strong>Two-Phase Commit (2PC)</strong>:</p>
<ul>
<li>Distributed transaction protocol</li>
<li>Prepare phase: All participants vote</li>
<li>Commit phase: Coordinator commits or aborts</li>
<li>Ensures atomicity across shards</li>
</ul>
<h3 id="development-architecture" class="position-relative d-flex align-items-center group">
<span>Development Architecture</span>
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<h4 id="codebase-organization" class="position-relative d-flex align-items-center group">
<span>Codebase Organization</span>
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</h4><p><strong>Zig Modules</strong>:</p>
<div class="highlight"><pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback"><span class="line"><span class="cl">geode/src/
</span></span><span class="line"><span class="cl">├── cli/ # Command-line interface
</span></span><span class="line"><span class="cl">├── query/ # Query engine
</span></span><span class="line"><span class="cl">│ ├── lexer.zig # Tokenization
</span></span><span class="line"><span class="cl">│ ├── parser.zig # Parsing
</span></span><span class="line"><span class="cl">│ ├── optimizer.zig # Query optimization
</span></span><span class="line"><span class="cl">│ └── executor.zig # Query execution
</span></span><span class="line"><span class="cl">├── storage/ # Storage layer
</span></span><span class="line"><span class="cl">│ ├── btree.zig # B+tree implementation
</span></span><span class="line"><span class="cl">│ ├── wal.zig # Write-ahead log
</span></span><span class="line"><span class="cl">│ └── mvcc.zig # MVCC and transactions
</span></span><span class="line"><span class="cl">├── network/ # Network layer
</span></span><span class="line"><span class="cl">│ ├── quic.zig # QUIC protocol
</span></span><span class="line"><span class="cl">│ └── protocol.zig # Wire protocol
</span></span><span class="line"><span class="cl">├── index/ # Index structures
</span></span><span class="line"><span class="cl">│ ├── hnsw.zig # Vector index
</span></span><span class="line"><span class="cl">│ └── bm25.zig # Full-text index
</span></span><span class="line"><span class="cl">└── test/ # Test framework
</span></span></code></pre></div>
<h4 id="canary-governance" class="position-relative d-flex align-items-center group">
<span>CANARY Governance</span>
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</h4><p><strong>Evidence-Based Development</strong>:</p>
<ul>
<li>CANARY markers track requirements</li>
<li>Each feature has corresponding test</li>
<li>Traceability from requirement to implementation</li>
<li>1,735 CANARY markers track 2,190+ requirements</li>
</ul>
<p><strong>Example CANARY Marker</strong>:</p>
<div class="highlight"><pre tabindex="0" class="chroma"><code class="language-zig" data-lang="zig"><span class="line"><span class="cl"><span class="c1">// CANARY: REQ=REQ-XXX; FEATURE="PatternMatching"; ASPECT=BasicMatch; STATUS=TESTED; TEST=TestBasicNodePatternMatch; OWNER=engine; UPDATED=2026-01-24
</span></span></span><span class="line"><span class="cl"><span class="c1">// Requirement: Support basic node pattern matching
</span></span></span><span class="line"><span class="cl"><span class="c1">// Evidence: TestBasicNodePatternMatch
</span></span></span></code></pre></div>
<h4 id="testing-strategy" class="position-relative d-flex align-items-center group">
<span>Testing Strategy</span>
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</h4><p><strong>Test Pyramid</strong>:</p>
<ul>
<li><strong>Unit tests</strong>: 1,000+ tests for individual functions</li>
<li><strong>Integration tests</strong>: 500+ tests for component interactions</li>
<li><strong>System tests</strong>: GQL conformance profile tests (ISO/IEC 39075:2024)</li>
<li><strong>Performance tests</strong>: Benchmark suite</li>
</ul>
<p><strong>Test Coverage</strong>: 97.4% (1,644/1,688 tests passing)</p>
<p><strong>ISO Conformance Profile</strong>: ISO/IEC 39075:2024 compliance (see conformance profile)</p>
<h3 id="related-documentation" class="position-relative d-flex align-items-center group">
<span>Related Documentation</span>
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</h3>
<h4 id="architecture-deep-dives" class="position-relative d-flex align-items-center group">
<span>Architecture Deep Dives</span>
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</h4><ul>
<li><strong><a
href="/docs/architecture/query-execution/"
>Query Execution</a>
</strong> - Query engine internals</li>
<li><strong><a
href="/docs/architecture/performance-and-scaling/"
>Performance and Scaling</a>
</strong> - Performance architecture</li>
<li><strong><a
href="/docs/architecture/distributed-architecture/"
>Distributed Architecture</a>
</strong> - Distributed systems</li>
<li><strong><a
href="/docs/architecture/wire-protocol/"
>Wire Protocol</a>
</strong> - QUIC protocol specification</li>
<li><strong><a
href="/docs/architecture/cli-design/"
>CLI Design</a>
</strong> - Command-line architecture</li>
</ul>
<h4 id="performance" class="position-relative d-flex align-items-center group">
<span>Performance</span>
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</h4><ul>
<li><strong><a
href="/categories/performance/"
>Performance Category</a>
</strong> - Performance optimization</li>
<li><strong><a
href="/categories/query/"
>Query Optimization</a>
</strong> - Query tuning</li>
<li><strong><a
href="/docs/query/indexing-and-optimization/"
>Indexing Guide</a>
</strong> - Index strategies</li>
</ul>
<h4 id="development" class="position-relative d-flex align-items-center group">
<span>Development</span>
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</h4><ul>
<li><strong><a
href="/categories/development/"
>Development Category</a>
</strong> - Development workflow</li>
<li><strong><a
href="/categories/contributing/"
>Contributing Category</a>
</strong> - Contributing guide</li>
<li><strong><a
href="/categories/zig/"
>Zig Category</a>
</strong> - Zig language resources</li>
</ul>
<h4 id="operations" class="position-relative d-flex align-items-center group">
<span>Operations</span>
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</h4><ul>
<li><strong><a
href="/categories/operations/"
>Operations Category</a>
</strong> - Production operations</li>
<li><strong><a
href="/categories/deployment-and-devops/"
>Deployment Category</a>
</strong> - Deployment patterns</li>
<li><strong><a
href="/categories/configuration/"
>Configuration Category</a>
</strong> - System configuration</li>
</ul>
<h3 id="related-tags" class="position-relative d-flex align-items-center group">
<span>Related Tags</span>
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</h3><ul>
<li><strong><a
href="/tags/mvcc/"
>MVCC</a>
</strong> - Multi-Version Concurrency Control</li>
<li><strong><a
href="/tags/acid/"
>ACID</a>
</strong> - ACID transaction guarantees</li>
<li><strong><a
href="/tags/quic/"
>QUIC</a>
</strong> - QUIC protocol</li>
<li><strong><a
href="/tags/query-optimization/"
>Query Optimization</a>
</strong> - Query execution</li>
<li><strong><a
href="/tags/indexing/"
>Indexing</a>
</strong> - Index architecture</li>
</ul>
<h3 id="architectural-resources" class="position-relative d-flex align-items-center group">
<span>Architectural Resources</span>
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</h3>
<h4 id="design-documents" class="position-relative d-flex align-items-center group">
<span>Design Documents</span>
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</h4><ul>
<li>Architecture overview diagrams</li>
<li>Component interaction flows</li>
<li>Data structure specifications</li>
<li>Protocol specifications</li>
</ul>
<h4 id="implementation-notes" class="position-relative d-flex align-items-center group">
<span>Implementation Notes</span>
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</h4><ul>
<li>Design decisions and rationale</li>
<li>Performance considerations</li>
<li>Trade-off analysis</li>
<li>Alternative approaches considered</li>
</ul>
<h4 id="future-architecture" class="position-relative d-flex align-items-center group">
<span>Future Architecture</span>
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</h4><ul>
<li>Planned enhancements</li>
<li>Scalability roadmap</li>
<li>Research directions</li>
<li>Community feedback integration</li>
</ul>
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<span>Contributing to Architecture</span>
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</h3><p>Understanding Geode’s architecture enables effective contributions:</p>
<p><strong>Code Contributions</strong>:</p>
<ul>
<li>Follow architectural patterns</li>
<li>Maintain separation of concerns</li>
<li>Add CANARY markers for features</li>
<li>Write tests for all changes</li>
</ul>
<p><strong>Architecture Discussions</strong>:</p>
<ul>
<li>Propose improvements on GitHub</li>
<li>Discuss trade-offs and alternatives</li>
<li>Share performance analysis</li>
<li>Review design documents</li>
</ul>
<h3 id="next-steps" class="position-relative d-flex align-items-center group">
<span>Next Steps</span>
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</h3><p><strong>Understanding query execution?</strong> Read <a
href="/docs/architecture/query-execution/"
>Query Execution Architecture</a>
for complete pipeline documentation.</p>
<p><strong>Optimizing performance?</strong> Check <a
href="/docs/architecture/performance-and-scaling/"
>Performance and Scaling</a>
for architectural guidance.</p>
<p><strong>Deploying distributed?</strong> Review <a
href="/docs/architecture/distributed-architecture/"
>Distributed Architecture</a>
for sharding and replication.</p>
<p><strong>Contributing code?</strong> See <a
href="/categories/contributing/"
>Contributing</a>
for development guidelines.</p>
<p><strong>Learning Zig?</strong> Browse <a
href="/categories/zig/"
>Zig Category</a>
for language resources.</p>
<hr>
<p><strong>Language</strong>: Zig 0.1.0+
<strong>Architecture</strong>: Layered, modular design
<strong>Concurrency</strong>: MVCC with SSI
<strong>Protocol</strong>: QUIC with TLS 1.3
<strong>Test Coverage</strong>: 97.4%
<strong>ISO Conformance Profile</strong>: ISO/IEC 39075:2024 compliance
<strong>Last Updated</strong>: January 2026
<strong>Geode Version</strong>: <strong>v0.2.18</strong>+</p>
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