...And I *do* know from testing I conducted a couple of years ago that using SIMILAR does marginally diminish the parse performance of well-written application code relative to using FORCE. Cary On Fri, Feb 6, 2009 at 2:03 PM, Jared Still <jkstill@xxxxxxxxx> wrote: > On Fri, Feb 6, 2009 at 8:06 AM, Martin Brown <martinfbrown@xxxxxxxxxxx>wrote: > >> >> Thanks for the reply, Gentlemen. We use "FORCE". I guess my next step is >> to test "SIMILAR" at some point and compare the results. >> > > Ah, that brings up more questions. > > Caveat: I have not done testing of 'FORCE' so some of my questions may be > naive. > > How much time is being recorded against library cache misses? > > Are new plans actually being generated for these statements? > > The reason I ask is that I don't know at what point Oracle determines > that an existing query plan may be used for a SQL statement that is > identical to one already seen, save for the use of literals in the > predicate. > > If Oracle is recording a cache miss, and then the CBO determines that > a new plan is not needed, the database may not actually be charging > much time against the cache misses. > > That statement may be ignorance on my part, but I just don't have time > right now to see how that works. > > Whereas you have more incentive to do so. :) > > Jared Still > Certifiable Oracle DBA and Part Time Perl Evangelist > >