Thanks to  Christopher Kings-Lynne <chris.kingslynne@gmail.com> for
initial version and Jeff Davis <pgsql@j-davis.com> for inspection

CONCURRENTLY.  Greg Stark, some further tweaks by me.

agreed these symbols are less easily confused.  I made new pg_operator
entries (with new OIDs) for the old names, so as to provide backward
compatibility while making it pretty easy to remove the old names in
some future release cycle.  This commit only touches the core datatypes,
contrib will be fixed separately.

Simon Riggs

blocking concurrent writes to the table.  Greg Stark, with a little help
from Tom Lane.

* some refactoring and simplify code int gistutil.c and gist.c
* now in some cases it can be called used-defined
  picksplit method for non-first column in index, but here
	is a place to do more.
* small fix of docs related to support NULL.

documenting GiST crash recovery procedures, as requested some time ago
by Teodor.  (The GiST chapter doesn't seem quite the right place for
the latter, but I'm not sure what else to do with it.)

particular the addition of bitmap scans and the relaxation of rules
about when multicolumn indexes can be used.  Also some minor editorial
work in other parts of the chapter.

to the existing X-direction tests.  An rtree class now includes 4 actual
2-D tests, 4 1-D X-direction tests, and 4 1-D Y-direction tests.
This involved adding four new Y-direction test operators for each of
box and polygon; I followed the PostGIS project's lead as to the names
of these operators.
NON BACKWARDS COMPATIBLE CHANGE: the poly_overleft (&<) and poly_overright
(&>) operators now have semantics comparable to box_overleft and box_overright.
This is necessary to make r-tree indexes work correctly on polygons.
Also, I changed circle_left and circle_right to agree with box_left and
box_right --- formerly they allowed the boundaries to touch.  This isn't
actually essential given the lack of any r-tree opclass for circles, but
it seems best to sync all the definitions while we are at it.

$Header: -> $PostgreSQL Changes ...

A couple other minor fixes.

makes a few more small improvements to runtime.sgml, and makes some SGML
conventions more consistent.

Neil Conway

of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects).  This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up.  Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.

class when lc_collate is not C.

vague cross-references with real links.

OPERATOR CLASS commands.  Further tweaking of documentation for same.

Fix up references to "PostgreSQL" rather than "Postgres". Was roughly
 evenly split between the two before. ref/ files not yet done.

GiST does now, too.  (Someone needs to write a description of GiST
to add to this chapter.  I don't know enough about it ...)

index usage.