Обсуждение: ...

Hello

I am new to development on postgreSQL. I and my collegues are working on 
mechanisms for query rewriting, containment and view set selections and we 
have chosen postgreSQL to work with.

I found out that the debug levels and EXPLAIN command lets you know the 
selection made at each step of the query execution. I wanted to know if 
there was or there can be a way to find out what query paths are considered 
while forming the query execution plan.

PostgreSQL documentation mentions that dynamic programming is used to 
evaluate different plans and reloptinfo stores details on each 
basic/intermediate relation. So does that mean that each cell of the dp 
matrix corresponds to one reloptinfo structure.

Do give your input on these issues.

thanks

sabrina

_________________________________________________________________
Get MSN 8 Dial-up Internet Service FREE for one month.  Limited time offer-- 
sign up now!   http://join.msn.com/?page=dept/dialup

"sabrina lal" <sabrina_lal2300@hotmail.com> writes:
> I found out that the debug levels and EXPLAIN command lets you know the 
> selection made at each step of the query execution. I wanted to know if 
> there was or there can be a way to find out what query paths are considered 
> while forming the query execution plan.

Compiling with -DOPTIMIZER_DEBUG provides some visibility into the
process, but I'd be the first to say we could use more.  Please feel
free to propose mechanisms for improving this.
        regards, tom lane

PS: please use a relevant Subject: line in future pghackers postings.