Chris, if you can influence the query, then you can try to lower the cost of the bitmap index access specifically to that query by using the (undocumented) OPT_PARAM hint introduced in 10g: select /*+ opt_param('optimizer_index_cost_adj', 10) */ ... If you can't modify the query but the query is static, you could apply this hint using Stored Outlines or SQL profiles in 10g. Regards, Randolf Oracle related stuff blog: http://oracle-randolf.blogspot.com/ SQLTools++ for Oracle (Open source Oracle GUI for Windows): http://www.sqltools-plusplus.org:7676/ http://sourceforge.net/projects/sqlt-pp/ > I am pretty much stuck on a bitmap costing problem. > > Any ideas on how to influence bitmap index cost, relative to full > table scan cost? Anything goes as long as it doesn't break b-tree > index costing. > > - optimizer_index_cost_adj - i will have to set this to 10 (10 times > cheaper) for bitmaps to be used. I am concerned about proper > calculations of b-tree indexes vs full table scans > > Any other ideas? _______________________________________________________________________ DSL zum Nulltarif + 20 Euro Extraprämie bei Online-Bestellung über die DSL Freundschaftswerbung! http://dsl.web.de/?ac=OM.AD.AD008K15279B7069a -- //www.freelists.org/webpage/oracle-l