The previous wording wasn't explicit enough, which could misled readers
into thinking that the locks acquired are more restricted in nature than
they really are.  The resulting optimism can be damaging to morale when
confronted with reality, as has been observed in the field.

Greg Smith

This patch is almost entirely cosmetic --- mostly cleaning up a lot of
neglected comments, and fixing code layout problems in places where the
patch made lines too long and then pgindent did weird things with that.
I did find a bug-of-omission in equalTupleDescs().

This adds collation support for columns and domains, a COLLATE clause
to override it per expression, and B-tree index support.

Peter Eisentraut
reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch

Block elements with verbatim formatting (literallayout, programlisting,
screen, synopsis) should be aligned at column 0 independent of the surrounding
SGML, because whitespace is significant, and indenting them creates erratic
whitespace in the output.  The CSS stylesheets already take care of indenting
the output.

Assorted markup improvements to go along with it.

The endterm attribute is mainly useful when the toolchain does not support
automatic link target text generation for a particular situation.  In  the
past, this was required by the man page tools for all reference page links,
but that is no longer the case, and it now actually gets in the way of
proper automatic link text generation.  The only remaining use cases are
currently xrefs to refsects.

Also fix and uncomment an old example of creating a GIST index, and make
a couple of other minor editorial adjustments.

choose an index name the same as it would do for an unnamed index constraint.
(My recent changes to the index naming logic have helped to ensure that this
will be a reasonable choice.)  Per a suggestion from Peter.

A necessary side-effect is to promote CONCURRENTLY to type_func_name_keyword
status, ie, it can't be a table/column/index name anymore unless quoted.
This is not all bad, since we have heard more than once of people typing
CREATE INDEX CONCURRENTLY ON foo (...) and getting a normal index build of
an index named "concurrently", which was not what they wanted.  Now this
syntax will result in a concurrent build of an index with system-chosen
name; which they can rename afterwards if they want something else.

multiple index entries in a holding area before adding them to the main index
structure.  This helps because bulk insert is (usually) significantly faster
than retail insert for GIN.

This patch also removes GIN support for amgettuple-style index scans.  The
API defined for amgettuple is difficult to support with fastupdate, and
the previously committed partial-match feature didn't really work with
it either.  We might eventually figure a way to put back amgettuple
support, but it won't happen for 8.4.

catversion bumped because of change in GIN's pg_am entry, and because
the format of GIN indexes changed on-disk (there's a metapage now,
and possibly a pending list).

Teodor Sigaev

qualifier, and add support for this in pg_dump.

This allows TOAST tables to have user-defined fillfactor, and will also
enable us to move the autovacuum parameters to reloptions without taking
away the possibility of setting values for TOAST tables.

another section if required by the platform (instead of the old way of
building them in section "l" and always transforming them to the
platform-specific section).

This speeds up the installation on common platforms, and it avoids some
funny business with the man page tools and build process.

maintenance_work_mem and effective_cache_size on index creation speed.

columns, and the new version can be stored on the same heap page, we no longer
generate extra index entries for the new version.  Instead, index searches
follow the HOT-chain links to ensure they find the correct tuple version.

In addition, this patch introduces the ability to "prune" dead tuples on a
per-page basis, without having to do a complete VACUUM pass to recover space.
VACUUM is still needed to clean up dead index entries, however.

Pavan Deolasee, with help from a bunch of other people.

databases, per gripe from hubert depesz lubaczewski.  Patch from
Simon Riggs.

tablespace(s) in which to store temp tables and temporary files.  This is a
list to allow spreading the load across multiple tablespaces (a random list
element is chosen each time a temp object is to be created).  Temp files are
not stored in per-database pgsql_tmp/ directories anymore, but per-tablespace
directories.

Jaime Casanova and Albert Cervera, with review by Bernd Helmle and Tom Lane.

Teodor Sigaev, with some kibitzing from Tom Lane.

CONCURRENTLY.

Gregory Stark

Standard English uses "may", "can", and "might" in different ways:

        may - permission, "You may borrow my rake."

        can - ability, "I can lift that log."

        might - possibility, "It might rain today."

Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice.  Similarly, "It may crash" is better stated, "It might crash".

per-column options for btree indexes.  The planner's support for this is still
pretty rudimentary; it does not yet know how to plan mergejoins with
nondefault ordering options.  The documentation is pretty rudimentary, too.
I'll work on improving that stuff later.

Note incompatible change from prior behavior: ORDER BY ... USING will now be
rejected if the operator is not a less-than or greater-than member of some
btree opclass.  This prevents less-than-sane behavior if an operator that
doesn't actually define a proper sort ordering is selected.

CONCURRENTLY.  Greg Stark, some further tweaks by me.

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

it can handle small fillfactors for ordinary-sized index entries without
failing on large ones; fix nbtinsert.c to distinguish leaf and nonleaf
pages; change the minimum fillfactor to 10% for all index types.

ITAGAKI Takahiro

clause implicitly whenever one is not given explicitly.  Remove concept
of a schema having an associated tablespace, and simplify the rules for
selecting a default tablespace for a table or index.  It's now just
(a) explicit TABLESPACE clause; (b) default_tablespace if that's not an
empty string; (c) database's default.  This will allow pg_dump to use
SET commands instead of tablespace clauses to determine object locations
(but I didn't actually make it do so).  All per recent discussions.

some other examples for CREATE DATABASE.

Gavin Sherry

There are various things left to do: contrib dbsize and oid2name modules
need work, and so does the documentation.  Also someone should think about
COMMENT ON TABLESPACE and maybe RENAME TABLESPACE.  Also initlocation is
dead, it just doesn't know it yet.

Gavin Sherry and Tom Lane.

> >> have to accept a full table scan when locating records.
> >
> > It indexes them, but "is null" is not an indexable operator, so you
> > can't directly solve the above with a 3-column index.  What you can do
> > instead is use a partial index, for instance
> >
> > create index i on CUSTOMER.WCCustOrderStatusLog (WCOrderStatusID)
> > where Acknowledged is null and Processing is null;
>
> That's a very nifty trick and exactly the sort of answer I was after!

Add CREATE INDEX doc mention of using partial indexes for IS NULL
indexing;  idea from Tom.

$Header: -> $PostgreSQL Changes ...

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

Neil Conway

discussion.  (Still have some work to do editing the remainder.)