Hi,
We're using PostgreSQL 8.2. Recently, in our production database, there was a severe performance impact.. Even though, we're regularly doing both:
1. VACUUM FULL ANALYZE once in a week during low-usage time and
2. ANALYZE everyday at low-usage time
Also, we noticed that the physical database size has grown upto 30 GB. But, if I dump the database in the form of SQL and import it locally in my machine, it was only 3.2 GB. Then while searching in Google to optimize database size, I found the following useful link:
http://www.linuxinsight.com/optimize_postgresql_database_size.html
It says that even vacuumdb or reindexdb doesn't really compact database size, only dump/restore does because of MVCC architecture feature in PostgreSQL and this has been proven here.
So, finally we decided to took our production database offline and performed dump/restore. After this, the physical database size has also reduced from 30 GB to 3.5 GB and the performance was also very good than it was before.
Physical database size was found using the following command:
du -sh /usr/local/pgsql/data/base/<database-oid>
I also cross-checked this size using "pg_size_pretty(pg_database_size(datname))".
Questions
1. Is there any version/update of PostgreSQL addressing this issue?
2. How in real time, this issues are handled by other PostgreSQL users without taking to downtime?
3. Any ideas or links whether this is addressed in upcoming PostgreSQL version 9.0 release?