Waiting for PostgreSQL 13 – Support for FF1-FF6 and SSSS datetime format patterns

On 16th of September 2019, Alexander Korotkov committed two patches:

First patch:

Support for SSSSS datetime format pattern
 
SQL Standard 2016 defines SSSSS format pattern for seconds past midnight in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause.  In our
datetime parsing engine we currently support it with SSSS name.
 
This commit adds SSSSS as an alias for SSSS.  Alias is added in favor of
upcoming jsonpath .datetime() method.  But it's also supported in to_date()/
to_timestamp() as positive side effect.
 
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Alexander Korotkov

and second one:

Support for FF1-FF6 datetime format patterns
 
SQL Standard 2016 defines FF1-FF9 format patters for fractions of seconds in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause.  Parsing
engine of upcoming .datetime() method will be shared with to_date()/
to_timestamp().
 
This patch implements FF1-FF6 format patterns for upcoming jsonpath .datetime()
method.  to_date()/to_timestamp() functions will also get support of this
format patterns as positive side effect.  FF7-FF9 are not supported due to
lack of precision in our internal timestamp representation.
 
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Heavily revised by me.
 
Discussion: https://postgr.es/m/-b497-f39a-923d-%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov

Continue reading Waiting for PostgreSQL 13 – Support for FF1-FF6 and SSSS datetime format patterns

Waiting for PostgreSQL 11 – MERGE SQL Command following SQL:2016

update!

It looks that this has been reverted


On 2nd of April 2018, Simon Riggs committed patch:

MERGE SQL Command following SQL:2016
 
MERGE performs actions that modify rows in the target table
using a source table or query. MERGE provides a single SQL
statement that can conditionally INSERT/UPDATE/DELETE rows
a task that would other require multiple PL statements.
e.g.
 
MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
  UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
  DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
  INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
  DO NOTHING;
 
MERGE works with regular and partitioned tables, including
column and row security enforcement, as well as support for
row, statement and transition triggers.
 
MERGE is optimized for OLTP and is parameterizable, though
also useful for large scale ETL/ELT. MERGE is not intended
to be used in preference to existing single SQL commands
for INSERT, UPDATE or DELETE since there is some overhead.
MERGE can be used statically from PL/pgSQL.
 
MERGE does not yet support inheritance, write rules,
RETURNING clauses, updatable views or foreign tables.
MERGE follows SQL Standard per the most recent SQL:2016.
 
Includes full tests and documentation, including full
isolation tests to demonstrate the concurrent behavior.
 
This version written from scratch in 2017 by Simon Riggs,
using docs and tests originally written in 2009. Later work
from Pavan Deolasee has been both complex and deep, leaving
the lead author credit now in his hands.
Extensive discussion of concurrency from Peter Geoghegan,
with thanks for the time and effort contributed.
 
Various issues reported via sqlsmith by Andreas Seltenreich
 
Authors: Pavan Deolasee, Simon Riggs
Reviewers: Peter Geoghegan, Amit Langote, Tomas Vondra, Simon Riggs
 
Discussion:
https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com
https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com

Continue reading Waiting for PostgreSQL 11 – MERGE SQL Command following SQL:2016