Subject Re: Optimal page size ?
Author Adam
--- In, "lacakus" <lacak@...> wrote:
> Hi, is there any recomendation for "page size" for FB 2.0 ?
> In IB6 doc I have read :
> "InterBase pages are 1KB by default. A typical production InterBase
> database gains 25 to 30 percent performance benefit from using a page
> size of 4KB."
> -Is this still true for FB2 ?

No FB 1.5 (and possibly eeven arlier) default new databases to 4K
unless otherwise specified, which probably answers your next question.

> -Why is default 1K, when 4K brings better performance ?
> (should be changed default in next releases of FB?)
> Next:
> "In general, you should use a page size larger than your largest
> record, although InterBase's data compression will
> generally shrink records that contain lots of string data ..."
> and
> "The number of records also affects the page size."
> -Is there any formula, how to calculate optimal page size ?
> (may it be documented?)

Not really (asides from the tips you mention). It is simplest and
fastest to just try it and measure.

> Next:
> "If any of your indexes are more than 4 levels deep, you should
> consider increasing the page size."
> -In my DB I use 4K page size. More of indexes are 2 levels deep, some
> 1 level and only 1 index on 1 table is 3 levels deep. Is 4K page size
> appropriate ?

Yes, 4K seems appropriate for your database.