enable_indexscan
No restart — settable per sessionboolean (on/off)
Debug toggle that strongly discourages index scans (default on).
What it does
Disabling enable_indexscan makes the planner avoid Index Scan nodes by inflating their cost. Combined with enable_bitmapscan it can prove that no usable index exists for a query — handy for diagnosis.
How to tune it
Leave on. Use only as a temporary diagnostic; production performance issues should be solved by getting the planner to choose indexes correctly, not by toggling this off.
Related plan nodes
Related parameters
- enable_seqscan
- enable_bitmapscan