On 5/12/2009 7:03 AM, Andreas Thiel wrote:
Hi All,
Maybe some questions are quite newbie ones, and I did try hard to scan
all the articles and documentation, but I did not find a satisfying
answer.
### My Issue No. 1: Index Size
Is such disk usage for indexes expected? What can I do to optimize? I
could not run yet a VACUUM on result_orig, as I hit into max_fsm_pages
limit
You'll like 8.4 then, as you no longer have to play with max_fsm_pages.
The fact that you're hitting max_fsm_pages suggests that you are
probably going to be encountering table bloat.
Of course, to get to 8.4 you're going to have to go through a dump and
reload of doom...
### My Issue No. 2: relpages and VACUUM
I have another table "test" which is - as starting point - created by
INSERTs and then UPDATE'd. It has the same columns and roughly the same
number of rows as table test_orig, but consumes 160 times the number of
pages. I tried VACUUM on this table but it did not change anything on
its relpages count. Maybe this is just because VACUUM without FULL does
not re-claim disk space, i.e. relpages stays as it is? I did observe
that after VACUUM, a REINDEX on this table did considerably shrink down
the size of its indexes (test_test_id, test_lt_id).
CLUSTER is often convenient for re-writing a highly bloated table.
You'll need enough free disk space to hold the real rows from the table
twice, plus the dead space once, while CLUSTER runs.
--
Craig Ringer
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