Submitted by: Paquito Ines (paquito)

Firebird 3 gives error "no current record for fetch operation" with queries filtering a table using an index, and with a second filter using a subselect with an aggregation function running over a second table correlated with the table of the outer select.

It can be reproduced with the following (nonsense) query:

select *
from rdb$relations r
where
rdb$relation_name = ''
or (
select sum(rdb$relation_id)
from rdb$database d
where d.rdb$character_set_name = r.rdb$owner_name
) > 0

-

FB 2.1, 2.5:
PLAN (D NATURAL)
PLAN (R NATURAL)

Runs ok (no results)

-

FB 3.0.4, 3.0.5.33182-0_x64_nightly, Firebird-4.0.0.1636-0_x64_nightly:
PLAN (D NATURAL)
PLAN (R NATURAL, R INDEX (RDB$INDEX_0))

Select Expression
-> Singularity Check
-> Aggregate
-> Filter
-> Table "RDB$DATABASE" as "D" Full Scan
Select Expression
-> Filter
-> Condition
-> Table "RDB$RELATIONS" as "R" Full Scan
-> Table "RDB$RELATIONS" as "R" Access By ID
-> Bitmap
-> Index "RDB$INDEX_0" Unique Scan

Statement failed, SQLSTATE = 22000
no current record for fetch operation

Commits: 1ccadfd c05df45