enable_hashjoin
No restart — settable per sessionboolean (on/off)
Debug toggle that strongly discourages hash joins (default on).
What it does
Inflates the cost of Hash Join nodes. Together with enable_mergejoin and enable_nestloop, it lets you compare a query's runtime under different join strategies.
How to tune it
Leave on. Hash joins are the right answer for many large-table equality joins; turn off only briefly to compare with other join strategies.
Related plan nodes
Related parameters
- enable_nestloop
- enable_mergejoin
- work_mem