ImGajeed76/pg-xpatch

PostgreSQL Table Access Method for delta-compressed versioned data

What's novel

PostgreSQL Table Access Method for delta-compressed versioned data

Code Analysis

11 files read · 4 rounds

A PostgreSQL Table Access Method extension that transparently stores versioned rows as delta-compressed differences between consecutive versions within groups, reconstructing full content on read via a shared-memory LRU cache and parallel scan infrastructure.

Strengths

Genuinely deep C implementation of a full PostgreSQL TAM with lock-striped shared-memory LRU cache, BLAKE3-hashed concurrent hash tables, proper MVCC with cascading-delete edge cases, parallel scan support, and a 30+ file test suite covering crash recovery, deadlocks, race conditions, and type roundtrips. The architecture is clean with clear separation between storage, compression, caching, and TAM interface layers.

Weaknesses

The xpatch_tam.c file at ~100KB is a monolith that could benefit from further decomposition, and the O(n) full-table scan in xpatch_get_max_seq (before cache hit) is a performance concern for large tables with many groups. The project is AGPL-licensed which limits commercial adoption without a separate license.

Score Breakdown

Innovation

6 (25%)

Craft

86 (35%)

Traction

17 (15%)

Scope

93 (25%)

Signal breakdown

Innovation

Not Fork+1

Code Novelty+2

Concept Novelty+2

Craft

Ci+5

Tests+8

Polish+1

Releases+5

Has License+5

Code Quality+26

Readme Quality+15

Recent Activity+7

Structure Quality+5

Commit Consistency+4

Has Dependency Mgmt+5

Traction

Forks+0

Stars+12

Hn Points+0

Watchers+0

Early Traction+5

Devto Reactions+0

Community Contribs+0

Scope

Commits+8

Languages+8

Subsystems+13

Bloat Penalty+0

Completeness+7

Contributors+5

Authored Files+15

Readme Code Match+3

Architecture Depth+7

Implementation Depth+8

Evidence

Commits

Contributors

Files

159

Active weeks

TestsCI/CDREADMELicenseContributing

Repository

Language

Python

Stars

Forks

License

AGPL-3.0