From http://www.postgresql.org/docs/8.0/interactive/maintenance.html:
"The first form, known as "lazy vacuum" or just VACUUM, marks expired
data in tables and indexes for future reuse; it does not attempt to
reclaim the space used by this expired data immediately. Therefore, the
table file is not shortened, and any unused space in the file is not
returned to the operating system."
This isn't completely accurate, though I'm not sure what a good wording
would be. Maybe:
"The first form, known as "lazy vacuum" or just VACUUM, marks expired
data in tables and indexes for future reuse. It only reclaims expired
space from tables if it is at the end of the table, and no empty space
is reclaimed from indexes."
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461