Subject Re: [firebird-support] Compress Database
Author Alexandre Benson Smith
At 08:03 30/03/2004 -0300, you wrote:

> It works.
> Now the FDB is with 380KB.
> I will have to do this usually?
> Marcello Fontolan
> marcello@...

Hi Marcelo,

A simple answer....

When you insert a lot of records, the database will grow, new pages will be
allocated and so on...

But when you delete a record, the database will not shrink, the space will
be "available" to be used on new inserted records.

So if you do a lot of inserts and then a lot of deletes, as you stated on
your original message, the database will have a lot of "free" space inside
the pages, so only a backup/restore could shrink the database, because when
you restore, the database will be recreated, and the pages will fills up
with data, so will not have a lot a free space on the pages...

I have never did a backup/restore cicle to reduce the database size... In
the daily work a mix of insert/delete don't let the database with lot of
free space lying around...

A backup/restore cicle will do a lot to a database, rebalance the index
tree, make it smaller, remove old record versions, etc. This could be used
the maintain teh database "clean", but I do not do it frequently on the
production servers, don't know if there is a magic number of days/months
when a backup/restore will be a good thing to do...

see you !

Alexandre Benson Smith
THOR Software e Comercial Ltda.
Santo Andre - Sao Paulo - Brazil


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