Query->hasSubLinks is always FALSE...

Bruce Momjian wrote:

You know, after all our lengthy discussions, this SubLink thing looks
pretty clean to me.

How are subselects going? Are you having to write a lot of code to get
it working? I would say after all our discussions and thinking, it took

Mmm ... =~ 1000 lines of code :)

me about two or three days to do the parser and rewrite for sublinks.
How many coding days is the rest taking? I am curious.

All was near ready Feb 6, but ... I got problems from canonification
routines in optimizer: 'where A AND B OR C ' becomes 'where (A OR C) AND (B OR C)'
and if C is subselect then ... C has to be processed twice (sometime) ...
I remember your question about handling 'A AND (B OR SubSelect)' - unfortunately,
I didn't see problems here (actually, there is no problem with this
conjunctive normal form :), but there are troubles in common case.

Ideas ?

For the moment I could leave this un-optimized, with possibility
of double subselect processing...

Vadim

Bruce Momjian wrote:

You know, after all our lengthy discussions, this SubLink thing looks
pretty clean to me.

How are subselects going? Are you having to write a lot of code to get
it working? I would say after all our discussions and thinking, it took

Mmm ... =~ 1000 lines of code :)

me about two or three days to do the parser and rewrite for sublinks.
How many coding days is the rest taking? I am curious.

All was near ready Feb 6, but ... I got problems from canonification
routines in optimizer: 'where A AND B OR C ' becomes 'where (A OR C) AND (B OR C)'
and if C is subselect then ... C has to be processed twice (sometime) ...
I remember your question about handling 'A AND (B OR SubSelect)' - unfortunately,
I didn't see problems here (actually, there is no problem with this
conjunctive normal form :), but there are troubles in common case.

Ideas ?

For the moment I could leave this un-optimized, with possibility
of double subselect processing...

I would leave it for later. We already have an optimizer explosion
problem when we have lots of OR's so at some point we may have to
revisit the cnf-ify process anyway. Commerical Ingres has or had the
same problem.

--
Bruce Momjian
maillist@candle.pha.pa.us

Bruce Momjian wrote:

me about two or three days to do the parser and rewrite for sublinks.
How many coding days is the rest taking? I am curious.

All was near ready Feb 6, but ... I got problems from canonification
routines in optimizer: 'where A AND B OR C ' becomes 'where (A OR C) AND (B OR C)'
and if C is subselect then ... C has to be processed twice (sometime) ...
I remember your question about handling 'A AND (B OR SubSelect)' - unfortunately,
I didn't see problems here (actually, there is no problem with this
conjunctive normal form :), but there are troubles in common case.

Ideas ?

For the moment I could leave this un-optimized, with possibility
of double subselect processing...

I would leave it for later. We already have an optimizer explosion
problem when we have lots of OR's so at some point we may have to
revisit the cnf-ify process anyway. Commerical Ingres has or had the
same problem.

Ok, follow this way...

Vadim