The former approach used ExclusiveLock on pg_database, which being a
cluster-wide lock meant only one of these operations could proceed at
a time; worse, it also blocked all incoming connections in ReverifyMyDatabase.
Now that we have LockSharedObject(), we can use locks of different types
applied to databases considered as objects.  This allows much more
flexible management of the interlocking: two CREATE DATABASEs need not
block each other, and need not block connections except to the template
database being used.  Similarly DROP DATABASE doesn't block unrelated
operations.  The locking used in flatfiles.c is also much narrower in
scope than before.  Per recent proposal.

This formulation requires every AM to provide amvacuumcleanup, unlike before,
but it's surely a whole lot cleaner.  Also, add an 'amstorage' column to
pg_am so that we can get rid of hardwired knowledge in DefineOpClass().

CONNECTION, fix a number of places that were missed (eg pg_dump support),
avoid executing an extra search of pg_database during startup.

support both FOR UPDATE and FOR SHARE in one command, as well as both
NOWAIT and normal WAIT behavior.  The more general code is actually
simpler and cleaner.

> 	o -Allow per-database permissions to be set via GRANT

Gevik Babakhani

> * %Disallow changing default expression of a SERIAL column?

Disallow changing DEFAULT expression of a SERIAL column.

> * -Disallow changing default expression of a SERIAL column

>   Another idea is to allow separate configuration files for each module,
>   or allow arbitrary SET commands to be passed to them.

> * Invalidate prepared queries, like INSERT, when the table definition
>   is altered

Libor Hoho?

CONSTRAINT, rather than affecting all constraints in all schemas (which
is what we used to do).  Also allow schema specifications.

Kris Jurka

information, and add a -r option to reset pg_control without affecting
xlog.

yuanjia lee

* -Allow WAL information to recover corrupted pg_controldata

configure.

equals sign.

 David Wheeler

documentation sections.  Also update SET/RESET to be consistent.

Nicolas Barbier

use RESET CONNECTION:

< * Add RESET SESSION command to reset all session state
> * Add RESET CONNECTION command to reset all session state
447c447
<   notify the protocol when a RESET SESSION command is used.
>   notify the protocol when a RESET CONNECTION command is used.

< * Add RESET CONNECTION command to reset all session state
> * Add RESET SESSION command to reset all session state
447c447
<   notify the protocol when a RESET CONNECTION command is used.
>   notify the protocol when a RESET SESSION command is used.

Hans-J?rgen Sch?nig

< 	o %Prevent child tables from altering or dropping constraints
<           like CHECK that were inherited from the parent table
< 	  like CHECK that are inherited by child tables
<
< 	  Dropping constraints should only be possible with CASCADE.
<
> 	  like CHECK that are inherited by child tables unless CASCADE
> 	  is used
> 	o %Prevent child tables from altering or dropping constraints
>           like CHECK that were inherited from the parent table

> * -Add transaction_timestamp(), statement_timestamp(), clock_timestamp()

transaction_timestamp() (just like now()).

Also update statement_timeout() to mention it is statement arrival time
that is measured.

Catalog version updated.

        o Support ISO INTERVAL syntax if units cannot be determined from
          the string, and are supplied after the string

          The SQL standard states that the units after the string specify
          the units of the string, e.g. INTERVAL '2' MINUTE should
          return '00:02:00'.  The current behavior has the units
          restrict the interval value to the specified unit or unit range,
          INTERVAL '70' SECOND returns '00:00:10'.

          For syntax that isn't uniquely ISO or PG syntax, like '1' or
          '1:30', treat as ISO if there is a range specification clause,
          and as PG if there no clause is present, e.g. interpret
          '1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
          interpret '1:30' as '1 hour, 30 minutes'.

          This makes common cases like SELECT INTERVAL '1' MONTH
          SQL-standard results.  The SQL standard supports a limited
          number of unit combinations and doesn't support unit names
          in the string.  The PostgreSQL syntax is more flexible in
          the range of units supported, e.g. PostgreSQL supports
          '1 year 1 hour', while the SQL standard does not.

   o -Add support for day-time syntax, INTERVAL '1 2:03:04'DAY TO
      SECOND

     o -Add support for day-time syntax, INTERVAL '1 2:03:04' DAY TO
        SECOND

< * -Eventually enable escape_string_warning and standard_conforming_strings
> * -Enable escape_string_warning and standard_conforming_strings
> * Make standard_conforming_strings the default in 8.3?
>
>   When this is done, backslash-quote should be prohibited in non-E''
>   strings because of possible confusion over how such strings treat
>   backslashes.  Basically, '' is always safe for a literal single
>   quote, while \' might or might not be based on the backslash
>   handling rules.
>

compatibility for release 7.2 and earlier.  I have not altered any
mentions of release 7.3 or later.  The release notes were not modified,
so the changes are still documented, just not in the main docs.

< 	o Fix psql's backslash commands more consistent
> 	o Fix psql's \d commands more consistent

< 	o Fix psql's \dn for various schema combinations (Neil)
> 	o Fix psql's backslash commands more consistent
625a626
> 	  http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php

        o Fix psql's \dn for various schema combinations (Neil)

          http://archives.postgresql.org/pgsql-hackers/2004-11/msg00014.php

patch separators in COPY.

Backpatch doubleing backslashes suggestion to 8.1.