Yes I'm sure.
With the left join FB does a full scan on Table_A and uses the Foreign
Key index on Table_B. The index on table_B.field_B is not used at all.
So you get millions of reads if the table contains millions of data
With the inner join the index on table_B.field_B is used and you only
get 1 read (if It's only 1 row that matches the condition)
Is it possible to force the optimizer tu use the index on table_B.field_B?
Regards
Carsten
Am 06.03.2019 um 21:49 schrieb Karol Bieniaszewski
[email protected] [firebird-support]:
Are you sure that this query looks like this?
For me such query use indexes in both cases left and inner.
Show full example with plans
Regards,
Karol Bieniaszewski
