Subject: [HACKERS] Aggregate function patches
Here are the aggregate function patches I originally sent in last December.
They fix sum() and avg() behavior for ints and floats when NULL values are
involved.
I was waiting to resubmit these until I had a chance to write a v6.0->v6.1
database upgrade script to ensure that existing v6.0 databases which have
not been reloaded for v6.1 do no break with the new aggregate behavior.
These scripts are included below. It's OK with me if someone wants to do
something different with the upgrade strategy, but something like this
was discussed a few weeks ago.
Also, there were a couple of small items which cropped up in doing a clean
install of 970403 (actually 970402 + 970403 changes since the full 970403
tar file appears to be damaged or at least suspect). They are the first
two patches below and can be omitted if desired (although I think they
aren't dangerous :).
Subject: [HACKERS] locale patches !
Hi there,
here are little patches to get Postgres 6.1 works with locale stuff.
This is a patch against 970402.tar.gz, there are no problem to apply them
by hand to 6.0 release. Collate stuff tested about 1-2 months in real
working database but I'm sure there must be no problem. US hackers
could vote against locale implementation ( locale for sure will affect to
speed of postgres ), so I introduce variable USE_LOCALE which
controls locale stuff. Non-US users now could use ~* operator
for searching and <order by> for strings with nation alphabet.
Please, don't forget, as I did first time, to set environment variable
LC_CTYPE and LC_COLLATE because backend get locale information from them.
I start postmaster from a little script, assuming that shell is Bash shell
it looks like:
#!/bin/sh
export LC_CTYPE=koi8-r
export LC_COLLATE=koi8-r
postmaster -B 1024 -S -D/usr/local/pgsql/data/ -o '-Fe'
> Please apply them to the direcory "backend/optimizer/geqo".
> Two new files with different crossover techniques are included.
> Standard procedure is optimization by means of "geqo_erx.c"
> (Edge Recombination Crossover).
From: "Martin S. Utesch" <utesch@aut.tu-freiberg.de>
Subject: [HACKERS] linux/alpha patches
These patches lay the groundwork for a Linux/Alpha port. The port doesn't
actually work unless you tweak the linker to put all the pointers in the
first 32 bits of the address space, but it's at least a start. It
implements the test-and-set instruction in Alpha assembly, and also fixes
a lot of pointer-to-integer conversions, which is probably good anyway.
Subject: [HACKERS] linux/alpha patches
These patches lay the groundwork for a Linux/Alpha port. The port doesn't
actually work unless you tweak the linker to put all the pointers in the
first 32 bits of the address space, but it's at least a start. It
implements the test-and-set instruction in Alpha assembly, and also fixes
a lot of pointer-to-integer conversions, which is probably good anyway.
2. IndexScanableOperand now uses match_indexkey_operand
instead of equal_indexkey_var (if we have some index on attribute X
then we shouldn't use it for 'where some_func(X) OP CONST').
/usr/include/limits.h (which quiets the costsize.c warnings)...under
FreeBSD, /usr/include/limits.h *includes* machine/limits.h, while under
Solaris, there is no such things as /usr/include/machine...
Problem with Solaris pointed out by Mark Wahl
The problem is that the function arguments are not considered as possible key
candidates for index scan and so only a sequential scan is possible inside
the body of a function. I have therefore made some patches to the optimizer
so that indices are now used also by functions. I have also moved the plan
debug message from pg_eval to pg_plan so that it is printed also for plans
genereated for function execution. I had also to add an index rescan to the
executor because it ignored the parameters set in the execution state, they
were flagged as runtime variables in ExecInitIndexScan but then never used
by the executor so that the scan were always done with any key=1. Very odd.
This means that an index rescan is now done twice for each function execution
which uses an index, the first time when the index scan is initialized and
the second when the actual function arguments are finally available for the
execution. I don't know what is the cost of an double index scan but I
suppose it is anyway less than the cost of a full sequential scan, at leat
for large tables. This is my patch, you must also add -DINDEXSCAN_PATCH in
Makefile.global to enable the changes.
Submitted by: Massimo Dal Zotto <dz@cs.unitn.it>
Select queries with an isnull or notnull clause, like "select * where
somefield isnull", crash the backend if the table has at least one index.
If the indices are deleted the queries work again. Also the explain
command fail in the same way.
The is caused by a bug in subroutine of the optimizer which doesn't check
null values in the clauses.
Submitted by: Massimo Dal Zotto <dz@cs.unitn.it>
Marc G. Fournier
Bruce Momjian
Vadim B. Mikheev
Bryan Henderson