Hi Vlad,
> In your example we see 7149 physical reads and 214192 times this pages
> was
> referenced by the engine. To read a record engine needs to access pointer
> page and
> (at least one) data page. You have ~100K records so we can explain ~200K
> fetches.
>
>
I think that when doing an exhaustive retrieval like this select count (*),
Firebird doesn't go back to the pointer page for each record but reads
every record on the page before it goes back to the pointer page, starting
the page/line index entry 0. For an indexed read, it would reference the
pointer page and the page/line index.
Cheers,
Ann
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