Subject Re: [firebird-support] select fieldA >= xxx is very very slow on Big table ?
Author Vander Clock Stephane
> Stick in an ORDER BY FIELDA - I think it will help.
>

unfortunatly not :( it's still take few minuts to return :(


> As I have explained
> several times recently - on this list at least once I think
>

aie :( sorry i unfortunatly don't see this message

> - Firebird
> has two index access strategies, two-phase and navigational. In the
> two-phase access mode, it first finds all matches in the index, setting
> bits in record number bitmap, then finds records from the bitmap. In
> navigational access it finds the first match in the index, returns that
> record, then finds the next match, returns the record and so on until
> done.
>
> Firebird normally uses two-phase access unless there's an ORDER BY
> that exactly matches a single index.
>

unfortunatly it's not look like this :( it's still take a lot of time to
return even with
an order by :(

select First 1 skip 0 ID from TABLEA where fieldA > xxx order by FieldA
with an index on fieldA


thanks for all ann !
st├ęphane


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