Where can I read about what vacuum database procedure is?

[Sempronius]

faq.holdemmanager.com consist only of "launch that program and press this button", but I can't find what exactly vacuum procedure does with database or with my handhistories and when I should do it and when I shouldn't.

I recently imported 2 mil hands in fresh new DB.

Please provide me a link with a bit detail description of what happens when you vacuum your DB and what doesn't.

[Patvs]

There are two types of purges (delete)

-options--> settings--> purge hands (will delete handhistory, hand from graph, $Won from sessions, etc. everything, so hand won't be used anymore for stats)
-options--> settings--> observed HH configuration--> purge hands--> will delete the handhistory and therefore the ability to replay the hand, but the hand will still be used for the graph, $Won from sessions and for the HUD.

--


Vacuum/reindex is similar to defragging your harddisk. If you have a database that reads:
rgohaogjaganhthnthgtmhHANDHISTORY1gtighehgg
then you delete HANDHISTORY1--> the PostgreSQL database will now read
rgohaogjaganhthnthgtmh____________1gtighehgg
and "____________" will still take up bytes (diskspace).
When you vacuum the database in pgadminIII it will delete all these spaces---> compacting the database, freeing up disk space