The optimiser in FB3 fails to use an index when there's an extra check in the where clause. The optimiser in FB2.5 can figure it out nicely. Code for creating and populating table in attachment. Example code below:
/**
* Here's the select. Please test with and without "sysid"
*/
select * from opt_test
where
--sysid = 1 and
clid = 23 and
cust_type = 1 and
cust_id = 73
order by order_no desc
Description
The optimiser in FB3 fails to use an index when there's an extra check in the where clause. The optimiser in FB2.5 can figure it out nicely. Code for creating and populating table in attachment. Example code below:
/**
* Here's the select. Please test with and without "sysid"
*/
select * from opt_test
where
--sysid = 1 and
clid = 23 and
cust_type = 1 and
cust_id = 73
order by order_no desc
Bug
Closed
Major
FB3 Optimiser chooses less efficient plan than FB2.5 optimiser
