{"id":79559,"plugin_id":"plugins_6ab40fcbcc3c81919e0c679fee35faaf","kind":"skill","collection_source":"plugin_package","comparison_source":null,"observed_at":"2026-11-04T00:11:25.629Z","digest":"06257dd711c97617320a1145a17d5c790233d38d3db665ba6fc27454f76af950","against":null,"payload":{"description":"Review NULL logic, time windows, timezone conversions, casts and decimal behavior.","included_files":[],"name":"null-and-time-semantics","skill_md_contents":"---\nname: null-and-time-semantics\ndescription: Review NULL logic, time windows, timezone conversions, casts and decimal behavior.\n---\n\n# Null And Time Semantics\n\n**Trigger:** Review NULL logic, time windows, timezone conversions, casts and decimal behavior.\n\n## Workflow\n1. Identify nullable input columns and differentiate unknown, missing and intentionally blank values.\n2. Check `=` vs `IS NULL`, `NOT IN` when subqueries contain NULL, CASE branching and null-safe comparisons by dialect.\n3. Define whether date windows use event, business or ingest time; use `[start, end)` timestamp boundaries when appropriate and justify local-time conversions.\n4. Verify identifier types (keep leading zeros as text), decimal arithmetic, overflow, implicit casts and collation/case sensitivity.\n5. Provide boundary examples and tests for midnight, DST transition, missing values and nonnumeric strings when relevant.\n\n## Critical standard\nNever assume string timestamps are UTC or treat every null as zero.\n\n## Evidence and execution\nOnly say \"executed\", \"passed\", \"observed\", \"optimized\" or \"deployed\" when a connected tool returned evidence for that claim. An SQL draft, a textual review, or local fixture proof alone is not production validation. Never ask the user to paste passwords or raw confidential records.\n\n## Supporting references\n- Read `../../references/null-time-types.md` when relevant.\n- Read `../../references/dialects.md` when relevant.\n\n## Return\nRevised SQL plus a short boundary-case table.\n"},"changes":[],"summary":"First saved snapshot. No earlier version is available for comparison.","summary_kind":"deterministic","summary_metadata":{}}