until Bind is received, so that actual parameter values are visible to the
planner.  Make use of the parameter values for estimation purposes (but
don't fold them into the actual plan).  This buys back most of the
potential loss of plan quality that ensues from using out-of-line
parameters instead of putting literal values right into the query text.

This patch creates a notion of constant-folding expressions 'for
estimation purposes only', in which case we can be more aggressive than
the normal eval_const_expressions() logic can be.  Right now the only
difference in behavior is inserting bound values for Params, but it will
be interesting to look at other possibilities.  One that we've seen
come up repeatedly is reducing now() and related functions to current
values, so that queries like ... WHERE timestampcol > now() - '1 day'
have some chance of being planned effectively.

Oliver Jowett, with some kibitzing from Tom Lane.

extensive change then what was suggested. I found the file path.c that
contained a lot of "Unix/Windows" agnostic functions so I added a function
there instead and removed the PATHSEP declaration in exec.c altogether. All
to keep things from scattering all over the code.

I also took the liberty of changing the name of the functions
"first_path_sep" and "last_path_sep". Where I come from (and I'm apparently
not alone given the former macro name PATHSEP), they should be called
"first_dir_sep" and "last_dir_sep". The new function I introduced, that
actually finds path separators, is now the "first_path_sep". The patch
contains changes on all affected places of course.

I also changed the documentation on dynamic_library_path to reflect the
chagnes.

Thomas Hallgren

when random_page_cost has a small value.  Per Manfred Koizar, though
I didn't use his equation exactly.

> * -Print table names with constraint names in error messages, or make constraint

ALTER TABLE tab ADD COLUMN col SERIAL, but we forgot to install the
dependency between the column and the sequence, so the sequence
would not go away if you dropped the table later.

sequences, as per recent discussion.  All these names are now of the
form table_column_type, with digits added if needed to make them unique.
Default constraint names are chosen to be unique across their whole schema,
not just within the parent object, so as to be more SQL-spec-compatible
and make the information schema views more useful.

Document limitations.

< * Allow hash buckets to fill disk pages, rather than being sparse
> * Pack hash index buckets onto disk pages more efficiently

> * Allow pg_dump to use multiple -t and -n switches

< * Order heap pointers on hash index pages by hash value and ctid
> * Allow hash buckets to fill disk pages, rather than being sparse

Euler Taveira de Oliveira

> * Order heap pointers on hash index pages by hash value and ctid

Serguei A. Mokhov

report from Tom Cook.

As a side effect, cause subscripts in INSERT targetlists to do something
more or less sensible; previously we evaluated such subscripts and then
effectively ignored them.  Another side effect is that UPDATE-ing an
element or slice of an array value that is NULL now produces a non-null
result, namely an array containing just the assigned-to positions.

This cleanup just cleans up a comment.

> * Add ON COMMIT capability to CREATE TABLE AS SELECT

array.

	Basically replaces (*a).b with a->b as it is everywhere else in
	Postgres.

Manfred Koizar

   . rename variables
     . cur_buffer -> dst_buffer
     . ToPage -> dst_page
     . cur_page -> dst_vacpage
   . move variable declarations into block where variable is used
   . various Asserts instead of elog(ERROR, ...)
   . extract functionality from repair_frag() into new routines
     . move_chain_tuple()
     . move_plain_tuple()
     . update_hint_bits()
   . create type ExecContext
   . add comments

Manfred Koizar