Query Cache
A performance optimization mechanism in databases and data warehouses that caches the results of executed queries and returns the cached result directly for identical or normalized-identical queries, avoiding redundant computation. Its key is typically the query text or a normalized hash.
Timeline (last 90 days)
Data warehouse query caches usually use the exact text of the query statement or its normalized hash as the key, and normalization generally only does lightweight processing (removing extra whitespace, unifying case, collapsing literal formats), without semantic-level rewriting.
Logically equivalent SQL (such as WHERE region = 'Northeast' and WHERE region IN ('Northeast')) produces different hashes, each triggering a full execution.
A query can be completely correct and still be a cache miss, which is a failure mode different from the text-to-SQL accuracy problem.
Query caching, result caching, and materialized views all presuppose that "the same question" produces "the same bytes", and that presupposition collapses when queries are generated by an LLM.
All Facts (4)
Data warehouse query caches usually use the exact text of the query statement or its normalized hash as the key, and normalization generally only does lightweight processing (removing extra whitespace, unifying case, collapsing literal formats), without semantic-level rewriting.
50%UnverifiedLogically equivalent SQL (such as WHERE region = 'Northeast' and WHERE region IN ('Northeast')) produces different hashes, each triggering a full execution.
50%UnverifiedA query can be completely correct and still be a cache miss, which is a failure mode different from the text-to-SQL accuracy problem.
50%UnverifiedQuery caching, result caching, and materialized views all presuppose that "the same question" produces "the same bytes", and that presupposition collapses when queries are generated by an LLM.
50%