Who can explain an AUTOINDEX

Hi there, I see the following phenomenon on my Machine -> dgux j2000i1 R4.20MU01 generic AViiON PentiumPro -> INFORMIX-OnLine Version 7.21.UD1 QUERY: ------ SELECT A.plz FROM Patient P, OUTER (daMitAN DMA, OUTER Anschrift A) WHERE P.datenID = 164011 AND DMA.datenID = 164011 AND DMA.class_type = P.class_type AND A.wmtDummyA2_ID = DMA.datenID AND A.wmtDummyA2_CT = DMA.class_type Estimated Cost: 826578 ^^^^^^ Estimated # of Rows Returned: 1 1) root.p: INDEX PATH (1) Index Keys: datenid class_type (Key-Only) Lower Index Filter: root.p.datenid = 164011 2) root.dma: INDEX PATH (1) Index Keys: datenid class_type (Key-Only) Lower Index Filter: (root.dma.datenid = 164011 AND root.dma.class_type = root.p.class_type ) 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 ..... Then i put an index into the DB with the Index Keys AUTOINDEX tell me and the query is fast as expected. Estimatet Cost: 20 and using INDEX PATH What is an AUTOINDEX exactly. I didn't found any hint in the Online-Docu (Or didn't look in the right index ;-) Thanks in advance Dirk Hellmann dirk.hellmann@laufenberg.com -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum