Crate stoolap 

Stoolap - High-performance embedded SQL database

Stoolap is a modern embedded SQL database written in pure Rust. It provides full ACID transactions with MVCC, a sophisticated cost-based query optimizer, and features that rival established databases like PostgreSQL and DuckDB.

Key Features

• MVCC Transactions - Full multi-version concurrency control with snapshot isolation
• Multiple Index Types - B-tree, Hash, and Bitmap indexes (auto-selected by data type)
• Multi-Column Indexes - Composite indexes for complex query patterns
• Cost-Based Optimizer - PostgreSQL-style optimizer with adaptive execution
• Parallel Query Execution - Automatic parallelization using Rayon
• Semantic Query Caching - Intelligent result caching with predicate subsumption
• AS OF Temporal Queries - Built-in time-travel queries
• Window Functions - ROW_NUMBER, RANK, DENSE_RANK, LAG, LEAD, NTILE, etc.
• CTEs - Common Table Expressions including recursive CTEs
• 101+ Built-in Functions - String, math, date/time, JSON, aggregate, window

Quick Start

use stoolap::api::Database;

// Open in-memory database
let db = Database::open_in_memory().unwrap();

// Create a table
db.execute("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)", ()).unwrap();

// Insert data
db.execute("INSERT INTO users VALUES (1, 'Alice', 30), (2, 'Bob', 25)", ()).unwrap();

// Query with window function
let rows = db.query("
    SELECT name, age, RANK() OVER (ORDER BY age DESC) as rank
    FROM users
", ()).unwrap();

Modules

• api - Public database interface (api::Database)
• core - Core types (DataType, Value, Row, Schema, Error)
• storage - Storage layer with MVCC, indexes, and expressions
• parser - SQL parser
• functions - 101+ SQL functions (scalar, aggregate, window)
• executor - Query executor with parallel execution
• optimizer - Cost-based query optimizer with cardinality feedback
• common - Utilities (BufferPool, I64Map, version)

Re-exports

pub use core::DataType;

pub use core::Error;

pub use core::IndexEntry;

pub use core::IndexType;

pub use core::IsolationLevel;

pub use core::Operator;

pub use core::Result;

pub use core::Row;

pub use core::Schema;

pub use core::SchemaBuilder;

pub use core::SchemaColumn;

pub use core::Value;

pub use common::BufferPool;

pub use common::I64Map;

pub use common::I64Set;

pub use common::PoolStats;

pub use common::SemVer;

pub use common::SmartString;

pub use storage::AndExpr;

pub use storage::BetweenExpr;

pub use storage::CastExpr;

pub use storage::ComparisonExpr;

pub use storage::CompoundExpr;

pub use storage::Expression;

pub use storage::InListExpr;

pub use storage::NotExpr;

pub use storage::NullCheckExpr;

pub use storage::OrExpr;

pub use storage::RangeExpr;

pub use storage::Config;

pub use storage::PersistenceConfig;

pub use storage::SyncMode;

pub use storage::EmptyResult;

pub use storage::EmptyScanner;

pub use storage::Engine;

pub use storage::Index;

pub use storage::MemoryResult;

pub use storage::QueryResult;

pub use storage::Scanner;

pub use storage::Table;

pub use storage::TemporalType;

pub use storage::Transaction;

pub use storage::VecScanner;

pub use storage::BTreeIndex;

pub use storage::MVCCEngine;

pub use storage::MVCCScanner;

pub use storage::MVCCTable;

pub use storage::MvccTransaction;

pub use storage::RangeScanner;

pub use storage::RowVersion;

pub use storage::SingleRowScanner;

pub use storage::TransactionEngineOperations;

pub use storage::TransactionRegistry;

pub use storage::TransactionState;

pub use storage::TransactionVersionStore;

pub use storage::VersionStore;

pub use storage::VisibilityChecker;

pub use storage::WriteSetEntry;

pub use storage::INVALID_TRANSACTION_ID;

pub use storage::RECOVERY_TRANSACTION_ID;

pub use storage::CheckpointMetadata;

pub use storage::WALEntry;

pub use storage::WALManager;

pub use storage::WALOperationType;

pub use storage::DEFAULT_WAL_BUFFER_SIZE;

pub use storage::DEFAULT_WAL_FLUSH_TRIGGER;

pub use storage::DEFAULT_WAL_MAX_SIZE;

pub use storage::deserialize_row_version;

pub use storage::deserialize_value;

pub use storage::serialize_row_version;

pub use storage::serialize_value;

pub use storage::IndexMetadata;

pub use storage::PersistenceManager;

pub use storage::PersistenceMeta;

pub use storage::DEFAULT_KEEP_SNAPSHOTS;

pub use storage::DEFAULT_SNAPSHOT_INTERVAL;

pub use functions::AggregateFunction;

pub use functions::AvgFunction;

pub use functions::CountFunction;

pub use functions::FirstFunction;

pub use functions::FunctionDataType;

pub use functions::FunctionInfo;

pub use functions::FunctionRegistry;

pub use functions::FunctionSignature;

pub use functions::FunctionType;

pub use functions::LastFunction;

pub use functions::MaxFunction;

pub use functions::MinFunction;

pub use functions::ScalarFunction;

pub use functions::SumFunction;

pub use functions::WindowFunction;

pub use functions::AbsFunction;

pub use functions::CeilingFunction;

pub use functions::CoalesceFunction;

pub use functions::ConcatFunction;

pub use functions::DenseRankFunction;

pub use functions::FloorFunction;

pub use functions::IfNullFunction;

pub use functions::LagFunction;

pub use functions::LeadFunction;

pub use functions::LengthFunction;

pub use functions::LowerFunction;

pub use functions::NowFunction;

pub use functions::NtileFunction;

pub use functions::NullIfFunction;

pub use functions::RankFunction;

pub use functions::RoundFunction;

pub use functions::RowNumberFunction;

pub use functions::SubstringFunction;

pub use functions::UpperFunction;

pub use executor::CacheStats;

pub use executor::CachedPlanRef;

pub use executor::CachedQueryPlan;

pub use executor::ColumnStatsCache;

pub use executor::ExecResult;

pub use executor::ExecutionContext;

pub use executor::Executor;

pub use executor::ExecutorResult;

pub use executor::QueryCache;

pub use executor::QueryPlanner;

pub use executor::StatsHealth;

pub use api::Database;

pub use api::FromRow;

pub use api::FromValue;

pub use api::NamedParams;

pub use api::ParamVec;

pub use api::Params;

pub use api::ResultRow;

pub use api::Rows;

pub use api::Statement;

pub use api::ToParam;

pub use api::Transaction as ApiTransaction;

Modules

api

Top-level Database API

common

Common utilities for Stoolap

core

Core types and definitions for Stoolap

executor

SQL Executor

functions

SQL Function System

optimizer

Query optimizer module for cost-based query planning

parser

SQL Parser

storage

Storage module for Stoolap

Macros

compact_vec

Creates a CompactVec containing the arguments.

named_params

Create named parameters for SQL queries

params

Create a parameter list for SQL queries

row

Macro for creating rows conveniently

validate_arg_count

Macro to validate argument count for scalar functions.