use Autoconf-approved method of testing for predefined symbols, and move
it down to where we know what compiler to run and how to run it.

in MVCC environment.  I do not trust this until Vadim says it's OK...

(it should just call the given operator, not look up an = operator).
Fix intltsel() so that all numeric data types are converted to double
before trying to estimate where the given comparison value is in the
known range of column values.  intltsel() still needs work, or replacement,
for non-numeric data types ... but for nonintegral numeric types it
should now be delivering reasonable estimates.

back out last...

testing somethign...

configure.in to determine if a system is ELF or not.  Note that some
of the tests earlier may be redundant but I took the safest route.

D'Arcy J.M. Cain

neqsel now behave as per my suggestions in pghackers a few days ago.
selectivity for < > <= >= should work OK for integral types as well, but
still need work for nonintegral types.  Since these routines have never
actually executed before :-(, this may result in some significant changes
in the optimizer's choices of execution plans.  Let me know if you see
any serious misbehavior.
CAUTION: THESE CHANGES REQUIRE INITDB.  pg_statistic table has changed.

every time I tweak the optimizer...

and target databases are of versions it knows about.

update temp tables with this setting.

logic in indxpath.c, avoid generation of redundant indexscan paths for the
same relation and index.

There is one section that changed, concernign startup...the rest is just
changes for v6.5->v6.5.1, so relatively harmless

v6.6's HISTORY file should reflect changes that went into all previous
releases, including v6.5.1 ...

just testing a script...

Nothing changed, just testing cvslog ...

for example in the regression test database, try
select * from tenk1 t1, tenk1 t2 where t1.unique1 = t2.unique2;
6.5 has this same bug ...

so that Case works in WHERE join clauses.  Temporary patch --- this routine
is one of many that ought to be changed to use centralized expression-tree-
walking logic.

detected this omission before.  Miscellaneous other cleanups.

IN and NOT IN operators.  Rewrite grotty implementation of IN-list
parsing ... look Ma, no global variable ...

rels that the inner path needs to join to, but it was only checking for
the first one.  Failure could only have been observed with an OR-clause
that mentions 3 or more tables, and then only if the bogus path was
actually selected as cheapest ...

be picked for one of the complex joins in rules test ... leading to
a different output ordering ...

optimizer rather than parser.  This has many advantages, such as not
getting fooled by chance uses of operator names ~ and ~~ (the operators
are identified by OID now), and not creating useless comparison operations
in contexts where the comparisons will not actually be used as indexquals.
The new code also recognizes exact-match LIKE and regex patterns, and
produces an = indexqual instead of >= and <=.

This change does NOT fix the problem with non-ASCII locales: the code
still doesn't know how to generate an upper bound indexqual for non-ASCII
collation order.  But it's no worse than before, just the same deficiency
in a different place...

Also, dike out loc_restrictinfo fields in Plan nodes.  These were doing
nothing useful in the absence of 'expensive functions' optimization,
and they took a considerable amount of processing to fill in.

to index_selectivity so that it can be handed an indexqual clause list
rather than a bunch of assorted derivative data.

The only place it was being used was as temporary storage in indxpath.c,
and the logic was wrong: the same restrictinfo node could get chosen to
carry the info for two different joins.  Right fix is to return a second
list of unjoined-relids parallel to the list of clause groups.