[...] > first, i used the optimizer statistics-option for that table > (orderline). > then, i created two indices:
usually the update statistics is run after index creation. > create index orderline1 on orderline(type,bzl1,orderlocal) > create index orderline2 on orderline(orderlocal) > > then, i tried out following the select-statement: > > explain select b.oid from orderline b where b.type=0 and > b.bzl1 = 'a' and > b.orderlocal in(0); > > this results in an EQUAL CONDITION FOR INDEX-strategy on > index orderline1 > with a pagecount of 2298 pages, Note: "pagecount" here. > which seems to be quite high to me. > > then, i remove the index orderline1. again, i use the same > select-statement > as above. with an EQUAL CONDITION FOR INDEX-strategy on index > orderline2, i > get a cost of 678 pages, Note: "cost" her. "Pagecount" is not the same as "cost" -- even if the two figures are in the same column of the output table. > a value that is still quite high, > but much smaller that 2298! > > there are two indices. according to the explain-output, the > system chooses > the index with a higher pagecount (=the less performant??). > > how can i optimize my statements then? creating indices by using the > pagecount-values? Please post the complete output of "EXPLAIN ...". Then maybe someone can help. Best regards Christian -- #include <std_disclaimer.h> /* The opinions stated above are my own and not necessarily those of my employer. */ -- MaxDB Discussion Mailing List For list archives: http://lists.mysql.com/maxdb To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
