On Sun, September 3, 2006 18:41, Gregory Stark wrote: > I'm confused, what exactly are you trying to predict? Whether each > parameter > will be some cached value? Or whether the cached plan was correct?
That's described in more detail in a separate thread ("prepared statements considered harmful"). In a nutshell, the algorithm detects pseudoconstant parameters to prepared statements, and keeps a small set of different plans optimized for recurring combinations of constants. >> So once again, does anyone know of any realistic logs that I can use for >> more useful simulations? > > You might look at the DBT test suite, iirc the TPCC spec it implements > intentionally mixes random queries with predictable queries. I considered the TPC benchmarks, but they're still benchmarks. When seen from one angle they try to look like real applications, but I'm worried that in testing this algorithm, I may be looking at them from a very different angle. I'd still need actual application logs to validate them! Jeroen ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings