Subject | Re: [firebird-support] Firebird optimize table |
---|---|
Author | Ann W. Harrison |
Post date | 2009-03-09T12:50:14Z |
Norman McFarlane wrote:
recombining, etc., so optimize table isn't necessary.
However, there is a command to set the index selectivity that you
should use periodically. Computing the selectivity of an index
is done on load, but not redone after major changes. Having a
reasonable selectivity is important to the optimizer in choosing
join orders.
Good luck,
Ann
>Firebird is quite efficient in managing space in tables - reusing,
> In my on-going project of converting a MySQL DB to Firebird, I have come
> across a SQL statement which reads as follows:
> OPTIMIZE TABLE <tablen ame>
> It is supposed to be useful for compacting tables which have a variable row
> width, which become extremely slow weith repeated deletes and inserts.
> Is there an equivalent in Firebird, and is it even necessary?
recombining, etc., so optimize table isn't necessary.
However, there is a command to set the index selectivity that you
should use periodically. Computing the selectivity of an index
is done on load, but not redone after major changes. Having a
reasonable selectivity is important to the optimizer in choosing
join orders.
Good luck,
Ann