This white paper may be of use: Designing Applications for Oracle Label Security http://www.oracle.com/technology/deploy/performance/pdf/design_for_ols.pdf On 3/7/08, Charles Schultz <sacrophyte@xxxxxxxxx> wrote: > After looking at all the information collected, Oracle Support has responded > by saying that the optimizer is actually taking a wild shot in the dark with > this selectivity number; the root of the issue is that we have VPD enabled > on the underlying tables, and since SYS_CONTEXT is non-deterministic, the > run time optimizer is not correctly determining the selectivity; more > importantly, the run time optimizer is unable to calculate the proper > number. I still have no idea how the number was actually generated; for all > intents and purposes, it could come from a random number generator, I guess. > =) The suggested work-around is to have SQL Tuner come up with a profile. I > know one can assign statistics to functions using the Data Cartridges, but > that seems like overkill, and the last time I plunged into that murky bog, I > came out with no noticeable benefits. > > Thanks for all those who responded. > -- Regards, Greg Rahn http://structureddata.org -- //www.freelists.org/webpage/oracle-l