PostgreSQL.

PostgreSQL database internals, optimization, extensions, and administration. Covers 12 sub-skills.

• PostgreSQL · 1 of 3

  Index Types & Strategies

  Which index type only supports equality comparisons (= operator)?

  AB-treeBHashCGINDBRIN

• PostgreSQL · 2 of 3

  Arrays, Enums, Ranges & Composite Types

  What index type is recommended for exclusion constraints on range columns?

  AB-tree (Balanced Tree Index)BGIN (Generalized Inverted Index)CHash (Hash Bucket Lookup)DGiST (Generalized Search Tree)

• PostgreSQL · 3 of 3

  VACUUM & Maintenance

  A busy table shows index bloat but negligible heap bloat. Which diagnosis best explains the asymmetry?

  ATable is insert-mostly with bulk partition attachment workflowBHeap pages are clustered by the physical primary key idCUpdates changed indexed columns, preventing HOT chainsDIndexes are GIN and cannot reuse freed heap-only tuples