SQL Fundamentals
Why Your Benchmark Measured the Cache
A query run five times in a row reports the speed of memory, not of the system. Which layer answered the request is the first thing to establish.
· 3 min
tag
#execution-plans
Articles tagged “execution-plans” on SQLPress — 3 in total.
3 articles
PostgreSQL
EXPLAIN, ANALYZE, BUFFERS: Three Different Questions
Which variant you ran decides whether the numbers in front of you are the planner's estimate or a measurement, and whether the pages came from cache.
· 4 min
PostgreSQL
Why an Index Is Not Used: the Estimate, Not the Index
An index the planner ignores is usually a row-estimate problem. The fix starts with what the optimizer expected, not with the index definition.
· 3 min