Day 10 of 14 35 minB-treeEXPLAINANALYZE
Make queries fast. Understand how a B-tree index finds rows, read query plans with EXPLAIN, create the right indexes, and know when an index won't help.
By the end of today you can
- Explain how an index speeds up lookups
- Read a query plan with EXPLAIN and EXPLAIN ANALYZE
- Create single-column, multi-column and expression indexes
- Recognise when PostgreSQL will (and won't) use an index
- Weigh the cost of indexes on writes and storage
What's inside
- 6 sections
- 3 diagrams and mind maps
- 6 code examples you can run
- 5-question quiz
- 1A table worth indexing
- 2Without an index: a sequential scan
- 3How a B-tree index works
- 4Add an index and compare
- 5When an index isn't used
- 6Other kinds of index
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