Subject | Re: [firebird-support] VIEW optimization |
---|---|
Author | Mark Rotteveel |
Post date | 2016-04-07T16:48:19Z |
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.
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 18:34
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 18:34
Hi All, VIEW: CREATE VIEW VIEW1 AS SELECT RDB$RELATION_FIELDS.RDB$RELATION_NAME, RDB$FIELD_NAME FROM RDB$RELATION_FIELDS JOIN RDB$RELATIONS ON RDB$RELATION_FIELDS.RDB$RELATION_NAME=RDB$RELATIONS.RDB$RELATION_NAME; SELECT: SELECT RDB$FIELD_NAME FROM VIEW1 PLAN: PLAN JOIN (VIEW1 RDB$RELATION_FIELDS NATURAL, VIEW1 RDB$RELATIONS INDEX (RDB$INDEX_0)) Plan contains the JOIN but that not needed for the selected field. Is this an SQL standard thing or just Firebird's optimizer not smart enough? 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/