query-planner

Google Cloud Spanner Query Planner Visualizer

build your own query planner

An eBPF based query planning tracer for PostgreSQL

Run the PostgreSQL Explain Visualizer 2 (pev2) from the command line.

Context Runtime — a database query planner for LLM context. Decides what a model sees before it answers; plans it, runs it through reused substrate, and learns from the outcome.

A tiny relational database written in Go

A minimal educational relational database management system (RDBMS) implemented in Java 17. The project demonstrates a custom SQL processing pipeline, including lexer, parser, semantic analysis, query planning, optimization, and execution. It features a storage engine with heap pages, a buffer pool, and supports indexing using B-trees and Hash

From-scratch database systems lab with SQL parser, slotted pages, WAL recovery, direct paged B+Tree index reads, query planner, and guided Workbench UI.

Hypothetical IVFFlat indexes for pgvector: test planner choices in EXPLAIN without building a physical index

openCypher front-end in Rust. Lex · parse · sema · plan · optimize · cost. Ships an MCP server (cypher-mcp). Storage-agnostic. v0.10 shipped.

Show all plans considered by the optimizer

A relational database engine written from scratch: slotted-page storage, an on-disk B+ tree, a SQL parser, a rule-based planner and a volcano executor.

Lint Postgres EXPLAIN ANALYZE plans for slow-query anti-patterns: seq scans on filtered big tables, hash joins spilling to disk, nested loops on too many outer rows, sort spilling, planner row-estimate skew. Reads JSON or text plans.

A columnar analytical database engine built from first principles in Rust: encodings, a segment format with pushdown, a hand-written SQL parser and a logical planner.

A real relational database engine from scratch in pure Python, zero dependencies: checksummed paged storage, a bounded buffer pool, a B+Tree with secondary indexes and overflow pages, a WAL with crash recovery, MVCC transactions, a SQL parser + planner (joins, aggregation), a DB-API 2.0 driver, and a client/server.

Rogue planets are starless planets, scientifically adrift in the cosmic dark alone

Small SQL query engine written from scratch in Go, with a volcano execution model, hash joins, aggregation, three-valued NULL semantics, and SQLite differential testing.

Model-driven data layer for industrial asset data: a typed DSL compiling to a relational schema, a Gorilla-encoded time series store, and a planner that pushes filters down and batches joins across both

B+-Baum mit gezaehlten Seitenzugriffen: Index gegen vollstaendigen Durchlauf, und wo der Planer irrt

実行計画とインデックスを原理から理解するために、Go で RDBMS を一から作る。触ったページ数を全レイヤで計測する。