Type Cache | Agent Skills Atlas

About this skill

PostgreSQL's per-backend type-info cache — src/backend/utils/cache/typcache.c — the TypeCacheEntry struct + lookuptypecache + domain constraint caching + RECORD typmod registry + the shared-parallel-worker variant. Loads when the user asks about typcache internals, why lookuptypecache might return NULL, how composite types get identified in parallel workers, RECORD types + typmod semantics, domain constraint invalidation, or when investigating a "type doesn't have the expected traits" bug (missing hash/equality/comparison functions). Skip when the ask is about typcache CALLERS (executor, planner — they just call the API), about pgtype catalog rows (that's catalog-conventions), or about implementing a new type (that's add-new-data-type scenario).

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Automated security scan: Partial

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0 potential findings · Scanned 11/4/2026 · Scanner 0.2.1

Content SHA-256: 8f1b405ccf6ddd3bb3942f5aa992da0f29e85719365aac94d325a2bc96cdde55

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Original listing metadata

Original name

type-cache

Original description

PostgreSQL's per-backend type-info cache — `src/backend/utils/cache/typcache.c` — the `TypeCacheEntry` struct + `lookup_type_cache` + domain constraint caching + RECORD typmod registry + the shared-parallel-worker variant. Loads when the user asks about `typcache` internals, why `lookup_type_cache` might return NULL, how composite types get identified in parallel workers, RECORD types + typmod semantics, domain constraint invalidation, or when investigating a "type doesn't have the expected traits" bug (missing hash/equality/comparison functions). Skip when the ask is about typcache CALLERS (executor, planner — they just call the API), about pg_type catalog rows (that's `catalog-conventions`), or about implementing a new type (that's `add-new-data-type` scenario).

About this listing

Category: Engineering
Reported license: PostgreSQL
Listing language (estimated): English
Review status: Not individually reviewed
Agent compatibility: Atlas installation supports Claude Code, Codex, and Cursor. Skill-specific dependencies and features are checked during setup.