distinguish index cost component from table component

Justin Pryzby <pryzby@telsasoft.com>

From: Justin Pryzby <pryzby@telsasoft.com>

To: pgsql-performance@postgresql.org

Date: 2020-01-03T14:14:27Z

Lists: pgsql-hackers, pgsql-performance

Is it possible to tell what component of the cost estimate of an index scan is
from the index reads vs heap ?

It would help to be able to set enable_bitmapscan=FORCE (to make all index
scans go through a bitmap).  Adding OR conditions can sometimes do this.  That
includes cost of bitmap manipulation, but it's good enough for me.

Or maybe explain should report it.

Commits

Doc: Fix list of storage parameters available for ALTER TABLE
- b9a9cb1bfd6e 10.12 landed
- b9988facaec8 11.7 landed
- c4c76d198e3d 12.2 landed
- 6de7bcb76f65 13.0 landed
Enhance docs for ALTER TABLE lock levels of storage parms
- 6f3a13ff058f 10.0 cited
Reduce lock levels for table storage params related to planning
- 21d4e2e20656 10.0 cited
Reduce lock levels for ALTER TABLE SET autovacuum storage options
- 47167b7907a8 9.6.0 cited
Reduce lock levels of some ALTER TABLE cmds
- e5550d5fec66 9.4.0 cited
Reduce lock levels of CREATE TRIGGER and some ALTER TABLE, CREATE RULE actions.
- 2dbbda02e7e6 9.1.0 cited
Support ALTER TABLESPACE name SET/RESET ( tablespace_options ).
- d86d51a95810 9.0.0 cited