indxpath.c refactoring
This simple refactoring patch moves all of the code associated with
Partial Index planning into a single file. This isolates it from other
code changes that may take place over the next few months, as well as
setting the scene for a number of changes that will hopefully take place
with that code.
This should allow work to continue on this undisturbed; more work will
happen within the 8.1 window, so please approve this patch to cvstip
now.
Changes likely on this code are
- redesigning the low level routines to allow them to perform their
stuff for both Partial Index and Constraint-based elimination (aka
Partitioning...)
- allowing equivalence class re-write
- allow handling for r-tree operators
- maybe GIST also??
Better to do this change now, than try to do it when code gets more
complex.
- Passes make check on current cvstip.
- No functional code changes of any kind, just moving between modules.
Changes:
- code removal from indxpath.c
- code addition to new module predtest.c
- no changes required to header files
- update Makefile
Best Regards, Simon Riggs
Simon Riggs <simon@2ndquadrant.com> writes:
This simple refactoring patch moves all of the code associated with
Partial Index planning into a single file.
Applied with some revisions -
* I put the new predtest.c file into optimizer/util, which seemed a more
plausible location than /path, and gave it its own header file.
* I thought check_partial_indexes() should stay in indxpath.c; it is an
application of the theorem-proving module to indexes, not part of the
prover proper.
* I took the opportunity to rename pred_test() to predicate_implied_by(),
which seems more clear about what it's doing and in which direction.
As for the future...
- redesigning the low level routines to allow them to perform their
stuff for both Partial Index and Constraint-based elimination (aka
Partitioning...)
The other main entry point should probably be called something like
predicate_refuted_by?
- allow handling for r-tree operators
I don't see anyone very excited about r-tree these days; have you
noticed that no one has stepped up to repair the known semantic errors?
I wouldn't spend any time on it in the prover.
- maybe GIST also??
The trouble with GiST is that the logical structure of each opclass
could be completely different from the next --- it's certainly not
possible to have a simple fixed table of implications. Again, we have
much more important fish to fry, anyway ...
regards, tom lane
I don't see anyone very excited about r-tree these days; have you
noticed that no one has stepped up to repair the known semantic errors?
I wouldn't spend any time on it in the prover.
That sort of thing is always self-fulfilling. If rtrees were fast,
logged and rad, then more people would use them :)
Chris
Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:
I don't see anyone very excited about r-tree these days; have you
noticed that no one has stepped up to repair the known semantic errors?
I wouldn't spend any time on it in the prover.
That sort of thing is always self-fulfilling. If rtrees were fast,
logged and rad, then more people would use them :)
The prophecy I'd like to see become self-fulfilling is that we get GIST
to production quality and then r-trees wither on the vine because
there's no reason to use them. I'm not aware of any reason to prefer
r-tree to an equivalent GIST opclass...
regards, tom lane
On Fri, 2005-06-10 at 18:33 -0400, Tom Lane wrote:
Simon Riggs <simon@2ndquadrant.com> writes:
This simple refactoring patch moves all of the code associated with
Partial Index planning into a single file.Applied with some revisions -
* I put the new predtest.c file into optimizer/util, which seemed a more
plausible location than /path, and gave it its own header file.* I thought check_partial_indexes() should stay in indxpath.c; it is an
application of the theorem-proving module to indexes, not part of the
prover proper.* I took the opportunity to rename pred_test() to predicate_implied_by(),
which seems more clear about what it's doing and in which direction.
Many thanks.
As for the future...
- redesigning the low level routines to allow them to perform their
stuff for both Partial Index and Constraint-based elimination (aka
Partitioning...)The other main entry point should probably be called something like
predicate_refuted_by?
Will do.
Best Regards, Simon Riggs