pgsql-server/src/backend/storage/smgr md.c

CVSROOT: /cvsroot
Module name: pgsql-server
Changes by: tgl@postgresql.org 03/01/06 20:19:12

Modified files:
src/backend/storage/smgr: md.c

Log message:
Tweak mdnblocks() to avoid doing lseek() on segments that it has
previously determined not to be the last segment of a relation.
This reduces the expected cost to one seek, rather than one seek per
segment. We can get away with this because truncation of a relation
will cause a relcache flush and so the md.c file descriptor will be
closed; when it is re-opened we will re-determine the last segment.