Re: Who can explain an AUTOINDEX

dirk.hellmann@laufenberg.com wrote: > > Hi there, > I see the following phenomenon on my Machine > -> dgux j2000i1 R4.20MU01 generic AViiON PentiumPro > -> INFORMIX-OnLine Version 7.21.UD1 > . . . query info snipped > > 3) root.a: AUTOINDEX PATH > ^^^^^^^^^ > (1) Index Keys: wmtdummya2_ct wmtdummya2_id > Lower Index Filter: (root.a.wmtdummya2_id = root.dma.datenid AND > root.a.wmtdummya2_ct = root.dma.class_type ) > > The estimated cost is _VERY_ high and an AUTOINDEX appear. What Online does > is that every free page from online ist occupied by this select and it run > and run and run ..... > AUTOINDEX is a condition determined by the Informix Optimizer where it will create a temporary index for the query. It's usually a good idea to create a permanent index if this condition persists. I know that it was used in the earlier versions; anyone see it in the later (7.x +) versions? John Carlson Informix DBA WH Smith, Inc.