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
