free-space-map
Skill1 starsChanged 6 months agoPostgreSQLView on GitHub
PostgreSQL's Free Space Map (FSM) — the tree-of-pages that tracks per-heap-page free space so `INSERT` / `COPY` / `heap_multi_insert` can find a page with room without scanning the whole relation. Covers `src/backend/storage/freespace/` (`freespace.c` + `fsmpage.c` + `indexfsm.c`), the tree layout (leaf-page nodes + 2 upper levels), category encoding (bucketed free-byte counts), the FSM lock discipline, VACUUM's post-scan `FreeSpaceMapVacuum`, and index FSM's simpler use case. Skip when the ask is about visibility map (VM — sibling but different subsystem) or about `pg_freespacemap` contrib module (that's the SQL introspection wrapper).
In this repository59 other files it gives its agents.
- CLAUDE.mdCLAUDE.md
- llms.txtllms.txt
- access-method-apisSkill
- aio-readstreamSkill
- backup-and-recoverySkill
- bgworker-and-extensionsSkill
- buffer-managerSkill
- build-and-runSkill
- catalog-conventionsSkill
- coding-styleSkill
- collation-providerSkill
- commit-message-styleSkill
- copy-familySkill
- corpus-chainSkill
- custom-scan-apiSkill
- debuggingSkill
- error-handlingSkill
- executor-and-plannerSkill
- extended-statisticsSkill
- extension-developmentSkill
- fdw-developmentSkill
- fmgr-and-spiSkill
- gucs-configSkill
- jsonpath-and-jsonbSkill
- lockingSkill
- logical-replicationSkill
- memory-contextsSkill
- memory-keepingSkill
- meta-commit-styleSkill
- multixactSkill
- node-infrastructureSkill
- parallel-querySkill
- parser-and-nodesSkill
- patch-submissionSkill
- pg-claudeSkill
- pg-feature-brainstormSkill
- pg-feature-planSkill
- pg-implementSkill
- pg-patch-reviewSkill
- pg-shadow-implementSkill
- pgstat-frameworkSkill
- pg-upgrade-internalsSkill
- physical-replicationSkill
- planner-cost-modelSkill
- plpgsql-internalsSkill
- process-lifecycleSkill
- psqlSkill
- replication-overviewSkill
- resource-ownersSkill
- review-checklistSkill
- row-level-securitySkill
- slru-infrastructureSkill
- snapshot-managementSkill
- testingSkill
- toast-storageSkill
- type-cacheSkill
- vacuum-autovacuumSkill
- wal-and-xlogSkill
- wire-protocolSkill
The file
We split this skill into the rules it gives an agent
12 rules. About 0 are common, 6 are distinctive, and 6 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈6
Distinctive · estimate
This author's own choices. Worth a look.
6
Very specific
Tied to their project's names, files or tools. Probably skip.
Licensed with conditions — read it at the source. We count its rules but don't quote them. Read them on GitHub.
≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
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