external projects, we should be careful about what parts of the GiST
API are considered implementation details, and which are part of the
public API. Therefore, I've moved internal-only declarations into
gist_private.h -- future backward-incompatible changes to gist.h should
be made with care, to avoid needlessly breaking external GiST extensions.

Also did some related header cleanup: remove some unnecessary #includes
from gist.h, and remove some unused definitions: isAttByVal(), _gistdump(),
and GISTNStrategies.

- make sure we always invoke user-supplied GiST methods in a short-lived
  memory context. This means the backend isn't exposed to any memory leaks
  that be in those methods (in fact, it is probably a net loss for most
  GiST methods to bother manually freeing memory now). This also means
  we can do away with a lot of ugly manual memory management in the
  GiST code itself.

- keep the current page of a GiST index scan pinned, rather than doing a
  ReadBuffer() for each tuple produced by the scan. Since ReadBuffer() is
  expensive, this is a perf. win

- implement dead tuple killing for GiST indexes (which is easy to do, now
  that we keep a pin on the current scan page). Now all the builtin indexes
  implement dead tuple killing.

- cleanup a lot of ugly code in GiST

< 	* Add internationalized message strings
> 	o Add internationalized message strings

than one heap page represented in the bitmap.  This is a bit ugly but
it cuts overhead fairly effectively in simple join cases.  Per example
from Sergey Koposov.

in an inconsistent state.  (This is only latent because in reality
ExecSeqRestrPos is dead code at the moment ... but someday maybe it won't
be.)  Add some comments about what the API for plan node mark/restore
actually is, because it's not immediately obvious.

MemoryContextResetChildren unless necessary.

tad faster.

when the blocks list is empty (there can surely be no freelist items if
the context contains no memory), and use MemSetAligned not MemSet to
clear the headers (we assume alignof(pointer) >= alignof(int32)).
Per discussion with Atsushi Ogawa.  He proposes some further hacking
that I'm not yet sold on, but these two changes are unconditional wins
since there is no case in which they make things slower.

PLs to use the standard pg_regress infrastructure.  No changes in the
tests themselves.  Andrew Dunstan

When one side of the join has a NULL, we don't want to uselessly try
to match it against every remaining tuple of the other side.  While
at it, rewrite the comparison machinery to avoid multiple evaluations
of the left and right input expressions and to use a btree comparator
where available, instead of double operator calls.  Also revise the
state machine to eliminate redundant comparisons and hopefully make it
more readable too.

and add an example showing assignment of a password.  Per suggestion
from Jari Aalto (via Martin Pitt).

no bug related to this functionality in HEAD, but it's worth adding a test
for anyway.) From Andrew Dunstan.

want to handle set inputs, it should just pass NULL for isDone, not make
its own failure check.

the "extern" keyword from function definitions, reorganize some
PG_GETARG_XXX() usage, and similar.

other PLs besides plpgsql.  Andrew Dunstan

of database name before table name
when VACUUMing or ANALYZing a table.

Cosimo Streppone

AtCommit_Portals is restarted when a portal is deleted. This is
necessary since the deletion of a portal may cause the deletion of
another which on rare occations may cause the iterator to return a
deleted portal an thus a renewed attempt delete.

Thomas Hallgren

instead of pg_usleep.

Backpatch to 8.0.X.

Robert Treat