Thread: pgsql: Add a GUC parameter seq_page_cost, and use that everywhere we
pgsql: Add a GUC parameter seq_page_cost, and use that everywhere we
From
tgl@postgresql.org (Tom Lane)
Date:
Log Message: ----------- Add a GUC parameter seq_page_cost, and use that everywhere we formerly assumed that a sequential page fetch has cost 1.0. This patch doesn't in itself change the system's behavior at all, but it opens the door to people adopting other units of measurement for EXPLAIN costs. Also, if we ever decide it's worth inventing per-tablespace access cost settings, this change provides a workable intellectual framework for that. Modified Files: -------------- pgsql/doc/src/sgml: config.sgml (r1.59 -> r1.60) (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml.diff?r1=1.59&r2=1.60) indexam.sgml (r2.12 -> r2.13) (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/indexam.sgml.diff?r1=2.12&r2=2.13) perform.sgml (r1.56 -> r1.57) (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/perform.sgml.diff?r1=1.56&r2=1.57) pgsql/src/backend/optimizer/path: costsize.c (r1.155 -> r1.156) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/costsize.c.diff?r1=1.155&r2=1.156) pgsql/src/backend/utils/adt: selfuncs.c (r1.205 -> r1.206) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/selfuncs.c.diff?r1=1.205&r2=1.206) pgsql/src/backend/utils/misc: guc.c (r1.320 -> r1.321) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.320&r2=1.321) postgresql.conf.sample (r1.177 -> r1.178) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample.diff?r1=1.177&r2=1.178) pgsql/src/include/optimizer: cost.h (r1.73 -> r1.74) (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/cost.h.diff?r1=1.73&r2=1.74)