sql

Expensive correlated subquery or nested loop

correlated subquery.*performance|Nested Loop.*cost.*rows.*loops=(\d{3,})

Fixes

1.Rewrite correlated subquery as a JOIN
2.Use a CTE to materialize the subquery result once
3.Add an index on the correlated column to speed inner lookups
4.Use EXISTS instead of IN for existence checks with large sets

performancesubquerynested-loop

Related Errors

PostgreSQL JSONB extracting from scalar

ERROR:.*cannot extract elements from a scalar.*jsonb

•Check value is an object/array before extraction: jsonb_typeof(col) = 'object'
•Use COALESCE with '{}' for null/scalar values

PostgreSQL JSONB operator type mismatch

ERROR:.*operator does not exist.*jsonb @> text

•Cast the right operand to jsonb: col @> '{"key": "val"}'::jsonb
•Use ->> operator for text extraction instead of ->

PostgreSQL full-text search config not found

ERROR:.*text search configuration.*does not exist

•Create the text search configuration or use a built-in one (english, simple)
•Install the pg_catalog extension if using a custom configuration