seq_page_cost v10

Parameter Type: Floating point

Default Value: 1

Range: 0 to 1.79769e+308

Minimum Scope of Effect: Per session

When Value Changes Take Effect: Immediate

Required Authorization to Activate: Session user

Sets the planner's estimate of the cost of a disk page fetch that is part of a series of sequential fetches. The default is 1.0. This value can be overridden for a particular tablespace by setting the tablespace parameter of the same name. (Refer to the ALTER TABLESPACE command in the PostgreSQL Core Documentation.)

The default value assumes very little caching, so it's frequently a good idea to reduce it. Even if your database is significantly larger than physical memory, you might want to try setting this parameter to less than 1 (rather than its default value of 1) to see whether you get better query plans that way. If your database fits entirely within memory, you can lower this value much more, perhaps to 0.1.