Subject | Re: [firebird-support] VIEW optimization |
---|---|
Author | Gabor Boros |
Post date | 2016-04-07T17:06:58Z |
2016. 04. 07. 18:48 keltezéssel, 'Mark Rotteveel' mark@...
[firebird-support] írta:
For me the two SELECT is equal. Is not? I don't understand why the JOIN
is in the PLAN when not needed for the result. My original problem is...
I have a complex SELECT and build up it at runtime in my application
include only the needed fields, JOINs in it. If create a VIEW from the
whole SELECT all JOIN etc executed even if only a single field needed
which can available without any JOIN or other thing.
Gabor
[firebird-support] írta:
> Why wouldn't it be necessary, this is an inner join, so the joined tableSELECT RDB$FIELD_NAME FROM RDB$RELATION_FIELDS
> needs to be evaluated if the matches row is present.
>
> SELECT RDB$FIELD_NAME FROM VIEW1
For me the two SELECT is equal. Is not? I don't understand why the JOIN
is in the PLAN when not needed for the result. My original problem is...
I have a complex SELECT and build up it at runtime in my application
include only the needed fields, JOINs in it. If create a VIEW from the
whole SELECT all JOIN etc executed even if only a single field needed
which can available without any JOIN or other thing.
Gabor