Subject Re: [firebird-support] VIEW optimization
Author Mark Rotteveel
For a join (inner join), the rows must exist in both tables, so both tables need to be evaluated.

Mark


----- Bericht beantwoorden -----
Van: "Gabor Boros gaborboros@... [firebird-support]" <firebird-support@yahoogroups.com>
Aan: <firebird-support@yahoogroups.com>
Onderwerp: [firebird-support] VIEW optimization
Datum: do, apr. 7, 2016 19:06

2016. 04. 07. 18:48 keltezéssel, 'Mark Rotteveel' mark@... 
[firebird-support] írta:
> Why wouldn't it be necessary, this is an inner join, so the joined table > needs to be evaluated if the matches row is present. > > SELECT RDB$FIELD_NAME FROM VIEW1
SELECT RDB$FIELD_NAME FROM RDB$RELATION_FIELDS 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 ------------------------------------ ------------------------------------ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Visit http://www.firebirdsql.org and click the Documentation item on the main (top) menu. Try FAQ and other links from the left-side menu there. Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-digest@yahoogroups.com firebird-support-fullfeatured@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscribe@yahoogroups.com <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/