Waiting for 9.4 – Add recovery_target=’immediate’ option.

On 25th of January, Heikki Linnakangas committed patch:

Add recovery_target='immediate' option.
 
This allows ending recovery as a consistent state has been reached. Without
this, there was no easy way to e.g restore an online backup, without
replaying any extra WAL after the backup ended.
 
MauMau and me.

Continue reading Waiting for 9.4 – Add recovery_target='immediate' option.

Waiting for 9.4 – Tablespace changes

On 18th of January, Stephen Frost committed patch:

Add ALTER TABLESPACE ... MOVE command
 
This adds a 'MOVE' sub-command to ALTER TABLESPACE which allows moving sets of
objects from one tablespace to another.  This can be extremely handy and avoids
a lot of error-prone scripting.  ALTER TABLESPACE ... MOVE will only move
objects the user owns, will notify the user if no objects were found, and can
be used to move ALL objects or specific types of objects (TABLES, INDEXES, or
MATERIALIZED VIEWS).

He followed it, with another commit:

Add CREATE TABLESPACE ... WITH ... Options
 
Tablespaces have a few options which can be set on them to give PG hints
as to how the tablespace behaves (perhaps it's faster for sequential
scans, or better able to handle random access, etc).  These options were
only available through the ALTER TABLESPACE command.
 
This adds the ability to set these options at CREATE TABLESPACE time,
removing the need to do both a CREATE TABLESPACE and ALTER TABLESPACE to
get the correct options set on the tablespace.
 
Vik Fearing, reviewed by Michael Paquier.

Continue reading Waiting for 9.4 – Tablespace changes

Waiting for 9.4 – Support ordered-set (WITHIN GROUP) aggregates.

On 23rd of December, Tom Lane committed patch:

Support ordered-set (WITHIN GROUP) aggregates.
 
This patch introduces generic support for ordered-set and hypothetical-set
aggregate functions, as well as implementations of the instances defined in
SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(),
percent_rank(), cume_dist()).  We also added mode() though it is not in the
spec, as well as versions of percentile_cont() and percentile_disc() that
can compute multiple percentile values in one pass over the data.
 
Unlike the original submission, this patch puts full control of the sorting
process in the hands of the aggregate's support functions.  To allow the
support functions to find out how they're supposed to sort, a new API
function AggGetAggref() is added to nodeAgg.c.  This allows retrieval of
the aggregate call's Aggref node, which may have other uses beyond the
immediate need.  There is also support for ordered-set aggregates to
install cleanup callback functions, so that they can be sure that
infrastructure such as tuplesort objects gets cleaned up.
 
In passing, make some fixes in the recently-added support for variadic
aggregates, and make some editorial adjustments in the recent FILTER
additions for aggregates.  Also, simplify use of IsBinaryCoercible() by
allowing it to succeed whenever the target type is ANY or ANYELEMENT.
It was inconsistent that it dealt with other polymorphic target types
but not these.
 
Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing,
and rather heavily editorialized upon by Tom Lane

Continue reading Waiting for 9.4 – Support ordered-set (WITHIN GROUP) aggregates.

Waiting for 9.4 – pg_prewarm, a contrib module for prewarming relationd data.

On 20th of December, Robert Haas committed patch:

pg_prewarm, a contrib module for prewarming relationd data.
 
Patch by me.  Review by Álvaro Herrera, Amit Kapila, Jeff Janes,
Gurjeet Singh, and others.

Continue reading Waiting for 9.4 – pg_prewarm, a contrib module for prewarming relationd data.

Waiting for 9.4 – Add ALTER SYSTEM command to edit the server configuration file.

On 18th of December, Tatsuo Ishii committed patch:

Add ALTER SYSTEM command to edit the server configuration file.
 
Patch contributed by Amit Kapila. Reviewed by Hari Babu, Masao Fujii,
Boszormenyi Zoltan, Andres Freund, Greg Smith and others.

On the next day, Fujii Masao committed patch:

Add tab completion for ALTER SYSTEM SET in psql.

Continue reading Waiting for 9.4 – Add ALTER SYSTEM command to edit the server configuration file.

Waiting for 9.4 – Allow time delayed standbys and recovery

On 12th of December, Simon Riggs committed patch:

Allow time delayed standbys and recovery
 
Set min_recovery_apply_delay to force a delay in recovery apply for commit and
restore point WAL records. Other records are replayed immediately. Delay is
measured between WAL record time and local standby time.
 
Robert Haas, Fabrízio de Royes Mello and Simon Riggs
Detailed review by Mitsumasa Kondo

Continue reading Waiting for 9.4 – Allow time delayed standbys and recovery

Waiting for 9.4 – Add new wal_level, logical, sufficient for logical decoding.

On 11th of December, Robert Haas committed patch:

Add new wal_level, logical, sufficient for logical decoding.
 
When wal_level=logical, we'll log columns from the old tuple as
configured by the REPLICA IDENTITY facility added in commit
<a class="text" href="/gitweb/?p=postgresql.git;a=object;h=07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65">07cacba983ef79be4a84fcd0e0ca3b5fcb85dd65</a>.  This makes it possible
a properly-configured logical replication solution to correctly
follow table updates even if they change the chosen key columns,
or, with REPLICA IDENTITY FULL, even if the table has no key at
all.  Note that updates which do not modify the replica identity
column won't log anything extra, making the choice of a good key
(i.e. one that will rarely be changed) important to performance
when wal_level=logical is configured.
 
Each insert, update, or delete to a catalog table will also log
the CMIN and/or CMAX values of stamped by the current transaction.
This is necessary because logical decoding will require access to
historical snapshots of the catalog in order to decode some data
types, and the CMIN/CMAX values that we may need in order to judge
row visibility may have been overwritten by the time we need them.
 
Andres Freund, reviewed in various versions by myself, Heikki
Linnakangas, KONDO Mitsumasa, and many others.

Continue reading Waiting for 9.4 – Add new wal_level, logical, sufficient for logical decoding.

Waiting for 9.4 – Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.

On 22nd of November, Tom Lane committed patch:

Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.
 
This patch adds the ability to write TABLE( function1(), function2(), ...)
as a single FROM-clause entry.  The result is the concatenation of the
first row from each function, followed by the second row from each
function, etc; with NULLs inserted if any function produces fewer rows than
others.  This is believed to be a much more useful behavior than what
Postgres currently does with multiple SRFs in a SELECT list.
 
This syntax also provides a reasonable way to combine use of column
definition lists with WITH ORDINALITY: put the column definition list
inside TABLE(), where it's clear that it doesn't control the ordinality
column as well.
 
Also implement SQL-compliant multiple-argument UNNEST(), by turning
UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)).
 
The SQL standard specifies TABLE() with only a single function, not
multiple functions, and it seems to require an implicit UNNEST() which is
not what this patch does.  There may be something wrong with that reading
of the spec, though, because if it's right then the spec's TABLE() is just
a pointless alternative spelling of UNNEST().  After further review of
that, we might choose to adopt a different syntax for what this patch does,
but in any case this functionality seems clearly worthwhile.
 
Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and
significantly revised by me

Continue reading Waiting for 9.4 – Support multi-argument UNNEST(), and TABLE() syntax for multiple functions.