Memoize operations cache the results of lookups, avoiding the need to do them again.

Less commonly looked up results may be evicted from the cache when more space is required for new entries.

Memoize was added in PostgreSQL 14, for nested loop operations where enough duplicates are expected that caching is estimated to be cheaper.

Memoize fields

• Parent Relationship

• Parallel Aware

• Async Capable

• Startup Cost

• Total Cost

• Plan Rows

• Plan Width

• Actual Startup Time

• Actual Total Time

• Actual Rows

• Actual Loops

• Output

• Cache Key

• Cache Mode

• Cache Hits

• Cache Misses

• Cache Evictions

• Cache Overflows

• Peak Memory Usage

Related operations

• Nested Loop

Related official docs

• Query planning — enable_memoize

• Resource consumption — work_mem

Further reading

• Memoize improved performance of nested loop joins — jOOQ

• Row count estimates – pgMustard

• Configuring work_mem – pgMustard