This question appeared couple of times on irc, so I figured I can do a blogpost about it.

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I assume that you're familiar with and services.

From today they are also available as services in TOR, using respectively: explain4pg4j5wbw.onion and paste4sql64vzyry.onion (of course you need to have TOR Browser or some other way to browse darknet).

Why I did that? Well, I believe that TOR is one of the greatest inventions ever, and I'd like to do something so that it will be less associated with drugs, porn, or other illegal activities. Don't realistically think that there will be many people using TOR to access my Pg-related services, but it is a thing that I could have done, so I did it.

While working on it, I also updated pgFormatter code under paste-site to newest version.

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Another one missed, quite a long time ago, too..:

On 4th of November 2016, Kevin Grittner committed patch:

Implement syntax for transition tables in AFTER triggers.
This is infrastructure for the complete SQL standard feature.  No
support is included at this point for execution nodes or PLs.  The
intent is to add that soon.
As this patch leaves things, standard syntax can create tuplestores
to contain old and/or new versions of rows affected by a statement.
References to these tuplestores are in the TriggerData structure.
C triggers can access the tuplestores directly, so they are usable,
but they cannot yet be referenced within a SQL statement.

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Some (long) time ago, someone on irc suggested that I add option to keep track of optimizations of queries.

Sorry, I forgot your name, and the mails disappeared in some crash.

Anyway – right now, when you are on some plan page, you can press “Add optimization" button, and you will be redirected to index page, but when you will add plan there, it will be understood to be plan from optimization of the query. Like this one.

You can have any number of optimizations per plan, and when viewing plan that has optimizations, or is an optimization of earlier plan – you will see this above plan table.

Whether you'll use it – it's up to you. Someone wanted it, and it looked like sensible thing to add, so there it is 🙂

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I missed it completely, but on 24th of March 2017, Alvaro Herrera committed patch:

Implement multivariate n-distinct coefficients
Add support for explicitly declared statistic objects (CREATE
STATISTICS), allowing collection of statistics on more complex
combinations that individual table columns.  Companion commands DROP
added too.  All this DDL has been designed so that more statistic types
can be added later on, such as multivariate most-common-values and
multivariate histograms between columns of a single table, leaving room
for permitting columns on multiple tables, too, as well as expressions.
This commit only adds support for collection of n-distinct coefficient
on user-specified sets of columns in a single table.  This is useful to
estimate number of distinct groups in GROUP BY and DISTINCT clauses;
estimation errors there can cause over-allocation of memory in hashed
aggregates, for instance, so it's a worthwhile problem to solve.  A new
special pseudo-type pg_ndistinct is used.
(num-distinct estimation was deemed sufficiently useful by itself that
this is worthwhile even if no further statistic types are added
immediately; so much so that another version of essentially the same
functionality was submitted by Kyotaro Horiguchi:
though this commit does not use that code.)
Author: Tomas Vondra.  Some code rework by Álvaro.
    Ideriha Takeshi

Afterwards, there were couple more commits related to it:

  • On 5th of April 2017, patch committed by Simon Riggs
  • On 17th of April 2017, patch committed by Alvaro Herrera
  • On 12nd of May 2017, patch committed by Alvaro Herrera

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On 7th of March 2017, Heikki Linnakangas committed patch:

Support SCRAM-SHA-256 authentication (RFC 5802 and 7677).
This introduces a new generic SASL authentication method, similar to the
GSS and SSPI methods. The server first tells the client which SASL
authentication mechanism to use, and then the mechanism-specific SASL
messages are exchanged in AuthenticationSASLcontinue and PasswordMessage
messages. Only SCRAM-SHA-256 is supported at the moment, but this allows
adding more SASL mechanisms in the future, without changing the overall
Support for channel binding, aka SCRAM-SHA-256-PLUS is left for later.
The SASLPrep algorithm, for pre-processing the password, is not yet
implemented. That could cause trouble, if you use a password with
non-ASCII characters, and a client library that does implement SASLprep.
That will hopefully be added later.
Authorization identities, as specified in the SCRAM-SHA-256 specification,
are ignored. SET SESSION AUTHORIZATION provides more or less the same
functionality, anyway.
If a user doesn't exist, perform a "mock" authentication, by constructing
an authentic-looking challenge on the fly. The challenge is derived from
a new system-wide random value, "mock authentication nonce", which is
created at initdb, and stored in the control file. We go through these
motions, in order to not give away the information on whether the user
exists, to unauthenticated users.
Bumps PG_CONTROL_VERSION, because of the new field in control file.
Patch by Michael Paquier and Heikki Linnakangas, reviewed at different
stages by Robert Haas, Stephen Frost, David Steele, Aleksander Alekseev,
and many others.

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On 6th of April 2017, Peter Eisentraut committed patch:

Identity columns
This is the SQL standard-conforming variant of PostgreSQL's serial
columns.  It fixes a few usability issues that serial columns have:
- CREATE TABLE / LIKE copies default but refers to same sequence
- cannot add/drop serialness with ALTER TABLE
- dropping default does not drop sequence
- need to grant separate privileges to sequence
- other slight weirdnesses because serial is some kind of special macro

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On 31st of March 2017, Andrew Dunstan committed patch:

Full Text Search support for json and jsonb
The new functions are ts_headline() and to_tsvector.
Dmitry Dolgov, edited and documented by me.

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On 30th of March 2017, Tom Lane committed patch:

Support \if ... \elif ... \else ... \endif in psql scripting.
This patch adds nestable conditional blocks to psql.  The control
structure feature per se is complete, but the boolean expressions
understood by \if and \elif are pretty primitive; basically, after
variable substitution and backtick expansion, the result has to be
"true" or "false" or one of the other standard spellings of a boolean
value.  But that's enough for many purposes, since you can always
do the heavy lifting on the server side; and we can extend it later.
Along the way, pay down some of the technical debt that had built up
around psql/command.c:
* Refactor exec_command() into a function per command, instead of
being a 1500-line monstrosity.  This makes the file noticeably longer
because of repetitive function header/trailer overhead, but it seems
much more readable.
* Teach psql_get_variable() and psqlscanslash.l to suppress variable
substitution and backtick expansion on the basis of the conditional
stack state, thereby allowing removal of the OT_NO_EVAL kluge.
* Fix the no-doubt-once-expedient hack of sometimes silently substituting
mainloop.c's previous_buf for query_buf when calling HandleSlashCmds.
(It's a bit remarkable that commands like \r worked at all with that.)
Recall of a previous query is now done explicitly in the slash commands
where that should happen.
Corey Huinker, reviewed by Fabien Coelho, further hacking by me

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On 23rd of March 2017, Peter Eisentraut committed patch:

Logical replication support for initial data copy
Add functionality for a new subscription to copy the initial data in the
tables and then sync with the ongoing apply process.
For the copying, add a new internal COPY option to have the COPY source
data provided by a callback function.  The initial data copy works on
the subscriber by receiving COPY data from the publisher and then
providing it locally into a COPY that writes to the destination table.
A WAL receiver can now execute full SQL commands.  This is used here to
obtain information about tables and publications.
Several new options were added to CREATE and ALTER SUBSCRIPTION to
control whether and when initial table syncing happens.
Change pg_dump option --no-create-subscription-slots to
--no-subscription-connect and use the new CREATE SUBSCRIPTION
... NOCONNECT option for that.
Author: Petr Jelinek

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