On 31st of March, Bruce Momjian committed patch:
psql: add asciidoc output format Patch by Szymon Guz, adjustments by me Testing by Michael Paquier, Pavel Stehule
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Tag: pg95
Waiting for 9.5 – Add stats for min, max, mean, stddev times to pg_stat_statements.
On 27th of March, Andrew Dunstan committed patch:
Add stats for min, max, mean, stddev times to pg_stat_statements. The new fields are min_time, max_time, mean_time and stddev_time. Based on an original patch from Mitsumasa KONDO, modified by me. Reviewed by Petr Jelínek.
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Waiting for 9.5 – Add support for index-only scans in GiST.
On 26th of March, Heikki Linnakangas committed patch:
Add support for index-only scans in GiST. This adds a new GiST opclass method, 'fetch', which is used to reconstruct the original Datum from the value stored in the index. Also, the 'canreturn' index AM interface function gains a new 'attno' argument. That makes it possible to use index-only scans on a multi-column index where some of the opclasses support index-only scans but some do not. This patch adds support in the box and point opclasses. Other opclasses can added later as follow-on patches (btree_gist would be particularly interesting). Anastasia Lubennikova, with additional fixes and modifications by me.
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Waiting for 9.5 – Add pg_rewind, for re-synchronizing a master server after failback.
On 23rd of March, Heikki Linnakangas committed patch:
Add pg_rewind, for re-synchronizing a master server after failback. Earlier versions of this tool were available (and still are) on github. Thanks to Michael Paquier, Alvaro Herrera, Peter Eisentraut, Amit Kapila, and Satoshi Nagayasu for review.
Waiting for 9.5 – Allow foreign tables to participate in inheritance. – A.K.A. PostgreSQL got sharding.
On 22nd of March, Tom Lane committed patch:
Allow foreign tables to participate in inheritance. Foreign tables can now be inheritance children, or parents. Much of the system was already ready for this, but we had to fix a few things of course, mostly in the area of planner and executor handling of row locks. As side effects of this, allow foreign tables to have NOT VALID CHECK constraints (and hence to accept ALTER ... VALIDATE CONSTRAINT), and to accept ALTER SET STORAGE and ALTER SET WITH/WITHOUT OIDS. Continuing to disallow these things would've required bizarre and inconsistent special cases in inheritance behavior. Since foreign tables don't enforce CHECK constraints anyway, a NOT VALID one is a complete no-op, but that doesn't mean we shouldn't allow it. And it's possible that some FDWs might have use for SET STORAGE or SET WITH OIDS, though doubtless they will be no-ops for most. An additional change in support of this is that when a ModifyTable node has multiple target tables, they will all now be explicitly identified in EXPLAIN output, for example: Update on pt1 (cost=0.00..321.05 rows=3541 width=46) Update on pt1 Foreign Update on ft1 Foreign Update on ft2 Update on child3 -> Seq Scan on pt1 (cost=0.00..0.00 rows=1 width=46) -> Foreign Scan on ft1 (cost=100.00..148.03 rows=1170 width=46) -> Foreign Scan on ft2 (cost=100.00..148.03 rows=1170 width=46) -> Seq Scan on child3 (cost=0.00..25.00 rows=1200 width=46) This was done mainly to provide an unambiguous place to attach "Remote SQL" fields, but it is useful for inherited updates even when no foreign tables are involved. Shigeru Hanada and Etsuro Fujita, reviewed by Ashutosh Bapat and Kyotaro Horiguchi, some additional hacking by me
Waiting for 9.5 – Use 128-bit math to accelerate some aggregation functions.
On 20th of March, Andres Freund committed patch:
Use 128-bit math to accelerate some aggregation functions. On platforms where we support 128bit integers, use them to implement faster transition functions for sum(int8), avg(int8), var_*(int2/int4),stdev_*(int2/int4). Where not supported continue to use numeric as a transition type. In some synthetic benchmarks this has been shown to provide significant speedups. Bumps catversion. Discussion: 544BB5F1.50709@proxel.se Author: Andreas Karlsson Reviewed-By: Peter Geoghegan, Petr Jelinek, Andres Freund, Oskari Saarenmaa, David Rowley
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Waiting for 9.5 – array_offset() and array_offsets()
On 18th of March, Alvaro Herrera committed patch:
array_offset() and array_offsets() These functions return the offset position or positions of a value in an array. Author: Pavel Stěhule Reviewed by: Jim Nasby
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Waiting for 9.5 – Replace checkpoint_segments with min_wal_size and max_wal_size.
On 23rd of February, Heikki Linnakangas committed patch:
Replace checkpoint_segments with min_wal_size and max_wal_size. Instead of having a single knob (checkpoint_segments) that both triggers checkpoints, and determines how many checkpoints to recycle, they are now separate concerns. There is still an internal variable called CheckpointSegments, which triggers checkpoints. But it no longer determines how many segments to recycle at a checkpoint. That is now auto-tuned by keeping a moving average of the distance between checkpoints (in bytes), and trying to keep that many segments in reserve. The advantage of this is that you can set max_wal_size very high, but the system won't actually consume that much space if there isn't any need for it. The min_wal_size sets a floor for that; you can effectively disable the auto-tuning behavior by setting min_wal_size equal to max_wal_size. The max_wal_size setting is now the actual target size of WAL at which a new checkpoint is triggered, instead of the distance between checkpoints. Previously, you could calculate the actual WAL usage with the formula "(2 + checkpoint_completion_target) * checkpoint_segments + 1". With this patch, you set the desired WAL usage with max_wal_size, and the system calculates the appropriate CheckpointSegments with the reverse of that formula. That's a lot more intuitive for administrators to set. Reviewed by Amit Kapila and Venkata Balaji N.
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Waiting for 9.5 – Use abbreviated keys for faster sorting of text datums.
On 19th of January, Robert Haas committed patch:
Use abbreviated keys for faster sorting of text datums. This commit extends the SortSupport infrastructure to allow operator classes the option to provide abbreviated representations of Datums; in the case of text, we abbreviate by taking the first few characters of the strxfrm() blob. If the abbreviated comparison is insufficent to resolve the comparison, we fall back on the normal comparator. This can be much faster than the old way of doing sorting if the first few bytes of the string are usually sufficient to resolve the comparison. There is the potential for a performance regression if all of the strings to be sorted are identical for the first 8+ characters and differ only in later positions; therefore, the SortSupport machinery now provides an infrastructure to abort the use of abbreviation if it appears that abbreviation is producing comparatively few distinct keys. HyperLogLog, a streaming cardinality estimator, is included in this commit and used to make that determination for text. Peter Geoghegan, reviewed by me.
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Waiting for 9.5 – vacuumdb: enable parallel mode
On 23rd of January, Alvaro Herrera committed patch:
vacuumdb: enable parallel mode This mode allows vacuumdb to open several server connections to vacuum or analyze several tables simultaneously. Author: Dilip Kumar. Some reworking by Álvaro Herrera Reviewed by: Jeff Janes, Amit Kapila, Magnus Hagander, Andres Freund
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