(ie, parameters instead of consts) will be treated as a range query.
We do not know the actual selectivities involved, but it seems like
a good idea to use a smaller estimate than we would use for two unrelated
inequalities.

That means you can now set your options in either or all of $PGDATA/configuration,
some postmaster option (--enable-fsync=off), or set a SET command. The list of
options is in backend/utils/misc/guc.c, documentation will be written post haste.

pg_options is gone, so is that pq_geqo config file. Also removed were backend -K,
-Q, and -T options (no longer applicable, although -d0 does the same as -Q).

Added to configure an --enable-syslog option.

changed all callers from TPRINTF to elog(DEBUG)

AUTHTYPE in config file.  Patch both branches.

trial implementation.

fmgr_faddr() in favor of new-style calls.  Lots of cleanup of
sloppy casts to use XXXGetDatum and DatumGetXXX ...

built-in procedures are named after the prosrc field of pg_proc (ie,
the actual C function name), not the proname field.  This did not use
to make a difference back when the two were always the same, but in the
presence of overloaded proname values we'd best try to use the C name
instead.  AFAICT this change affects no existing code, but it is
necessary to be able to get at some built-in functions that no macro
was being generated for before.

to 10, and be consistent about whether it counts the trailing null (it
does not).  Also increase MAXDATELEN to be sure no buffer overflows are
caused by the longer MAXTZLEN.

the src/include tree, so that -I backend is no longer necessary anywhere.
Also, clean up some bit rot in contrib tree.

CurrentTriggerData is history.

pg_language entries.