Re: [HACKERS] VACUUM produces odd freespace values

2010-09-17 Thread Bruce Momjian
Thom Brown wrote: > > VACUUM mvcc_demo; > > VACUUM > > SELECT pg_relation_size('mvcc_demo'); > > ?pg_relation_size > > -- > > ? ? ? ? ? ? ? ?0 > > (1 row) > > > > That's odd. When I delete val 2, the freespace goes back up in 9.0rc1 > (attached). Your numbers are odd too. With o

Re: [HACKERS] VACUUM produces odd freespace values

2010-09-17 Thread Thom Brown
On 18 September 2010 02:00, Bruce Momjian wrote: > Bruce Momjian wrote: >> Can anyone explain why VACUUM after INSERT shows steadily decreasing >> freespace, while DELETE of the same rows does not decrease consistently? >> >> Specifically, after one row is inserted I see: >> >>       SELECT pg_fre

Re: [HACKERS] VACUUM produces odd freespace values

2010-09-17 Thread Bruce Momjian
Bruce Momjian wrote: > Can anyone explain why VACUUM after INSERT shows steadily decreasing > freespace, while DELETE of the same rows does not decrease consistently? > > Specifically, after one row is inserted I see: > > SELECT pg_freespace('mvcc_demo'); >pg_freespace > -

[HACKERS] VACUUM produces odd freespace values

2010-09-17 Thread Bruce Momjian
Can anyone explain why VACUUM after INSERT shows steadily decreasing freespace, while DELETE of the same rows does not decrease consistently? Specifically, after one row is inserted I see: SELECT pg_freespace('mvcc_demo'); pg_freespace -- (0,8128)