<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	>

<channel>
	<title>select * from depesz; &#187; constraint</title>
	<atom:link href="http://www.depesz.com/tag/constraint/feed/" rel="self" type="application/rss+xml" />
	<link>http://www.depesz.com</link>
	<description></description>
	<lastBuildDate>Mon, 07 May 2012 20:34:27 +0000</lastBuildDate>
	<language>en</language>
	<sy:updatePeriod>hourly</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>
	<generator>http://wordpress.org/?v=3.3.2</generator>
		<item>
		<title>Waiting for 9.2 &#8211; Range data types</title>
		<link>http://www.depesz.com/2011/11/07/waiting-for-9-2-range-data-types/</link>
		<comments>http://www.depesz.com/2011/11/07/waiting-for-9-2-range-data-types/#comments</comments>
		<pubDate>Mon, 07 Nov 2011 14:39:09 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[exclude]]></category>
		<category><![CDATA[gist]]></category>
		<category><![CDATA[pg92]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[range]]></category>
		<category><![CDATA[unique]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=2320</guid>
		<description><![CDATA[On 3rd of November, Heikki Linnakangas committed patch: Support range DATA types. &#160; Selectivity estimation functions are missing FOR SOME range TYPE operators, which IS a TODO. &#160; Jeff Davis Well, the commit log is quite laconic. So let&#8217;s dig a bit deeper. Every once in a while you need to represent range of values. [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2011/11/07/waiting-for-9-2-range-data-types/feed/</wfw:commentRss>
		<slash:comments>12</slash:comments>
		</item>
		<item>
		<title>Waiting for 9.2 &#8211; NOT VALID CHECKS</title>
		<link>http://www.depesz.com/2011/07/01/waiting-for-9-2-not-valid-checks/</link>
		<comments>http://www.depesz.com/2011/07/01/waiting-for-9-2-not-valid-checks/#comments</comments>
		<pubDate>Thu, 30 Jun 2011 22:16:23 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[check]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[nextval]]></category>
		<category><![CDATA[not valid]]></category>
		<category><![CDATA[pg92]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[valid]]></category>
		<category><![CDATA[validate]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=2213</guid>
		<description><![CDATA[On 30th of June, Alvaro Herrera committed patch: Enable CHECK constraints to be declared NOT VALID &#160; This means that they can initially be added to a large existing table without checking its initial contents, but new tuples must comply to them; a separate pass invoked by ALTER TABLE / VALIDATE can verify existing data [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2011/07/01/waiting-for-9-2-not-valid-checks/feed/</wfw:commentRss>
		<slash:comments>3</slash:comments>
		</item>
		<item>
		<title>Waiting for 9.1 &#8211; INVALID FOREIGN KEYS</title>
		<link>http://www.depesz.com/2011/02/22/waiting-for-9-1-invalid-foreign-keys/</link>
		<comments>http://www.depesz.com/2011/02/22/waiting-for-9-1-invalid-foreign-keys/#comments</comments>
		<pubDate>Tue, 22 Feb 2011 14:38:14 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[foreign key]]></category>
		<category><![CDATA[lock]]></category>
		<category><![CDATA[locks]]></category>
		<category><![CDATA[not valid]]></category>
		<category><![CDATA[pg91]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[valid]]></category>
		<category><![CDATA[validate]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=2106</guid>
		<description><![CDATA[On 8th of February, Simon Riggs committed patch: Extend ALTER TABLE to allow Foreign Keys to be added without initial validation. FK constraints that are marked NOT VALID may later be VALIDATED, which uses an ShareUpdateExclusiveLock on constraint table and RowShareLock on referenced table. Significantly reduces lock strength and duration when adding FKs. New state [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2011/02/22/waiting-for-9-1-invalid-foreign-keys/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Waiting for 9.1 &#8211; Add UNIQUE/PRIMARY KEY with index</title>
		<link>http://www.depesz.com/2011/02/19/waiting-for-9-1-add-uniqueprimary-key-with-index/</link>
		<comments>http://www.depesz.com/2011/02/19/waiting-for-9-1-add-uniqueprimary-key-with-index/#comments</comments>
		<pubDate>Sat, 19 Feb 2011 12:04:35 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[bloat]]></category>
		<category><![CDATA[concurrently]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[index]]></category>
		<category><![CDATA[pg91]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[primary key]]></category>
		<category><![CDATA[reindex]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=2102</guid>
		<description><![CDATA[On 25th of January, Tom Lane committed patch: Implement ALTER TABLE ADD UNIQUE/PRIMARY KEY USING INDEX. &#160; This feature allows a unique or pkey constraint to be created using an already-existing unique index. While the constraint isn't very functionally different from the bare index, it's nice to be able to do that for documentation purposes. [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2011/02/19/waiting-for-9-1-add-uniqueprimary-key-with-index/feed/</wfw:commentRss>
		<slash:comments>2</slash:comments>
		</item>
		<item>
		<title>CHAR(x) vs. VARCHAR(x) vs. VARCHAR vs. TEXT &#8211; UPDATED 2010-03-03</title>
		<link>http://www.depesz.com/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/</link>
		<comments>http://www.depesz.com/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/#comments</comments>
		<pubDate>Tue, 02 Mar 2010 11:33:56 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[char]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[datatype]]></category>
		<category><![CDATA[domain]]></category>
		<category><![CDATA[length]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[text]]></category>
		<category><![CDATA[trigger]]></category>
		<category><![CDATA[varchar]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1610</guid>
		<description><![CDATA[Fight! But more seriously &#8211; people tend to use various data types, and there have been some myths about them, so let&#8217;s see how it really boils down. First of all &#8211; All those data types are internally saved using the same C data structure &#8211; varlena. Thanks to this we can be nearly sure [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/feed/</wfw:commentRss>
		<slash:comments>39</slash:comments>
		</item>
		<item>
		<title>Waiting for 8.5 &#8211; exclusion constraints</title>
		<link>http://www.depesz.com/2010/01/03/waiting-for-8-5-exclusion-constraints/</link>
		<comments>http://www.depesz.com/2010/01/03/waiting-for-8-5-exclusion-constraints/#comments</comments>
		<pubDate>Sun, 03 Jan 2010 21:51:28 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[conflict]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[exclude]]></category>
		<category><![CDATA[hotel]]></category>
		<category><![CDATA[pg85]]></category>
		<category><![CDATA[pg90]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[rooms]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1563</guid>
		<description><![CDATA[On 7th of December, Tom Lane committed patch by Jeff Davis that adds general exclusion constraints: Log Message: ----------- Add exclusion constraints, which generalize the concept of uniqueness to support any indexable commutative operator, not just equality. Two rows violate the exclusion constraint if &#34;row1.col OP row2.col&#34; is TRUE for each of the columns in [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2010/01/03/waiting-for-8-5-exclusion-constraints/feed/</wfw:commentRss>
		<slash:comments>7</slash:comments>
		</item>
		<item>
		<title>Waiting for 8.5 &#8211; conditional triggers</title>
		<link>http://www.depesz.com/2009/12/23/waiting-for-8-5-conditional-triggers/</link>
		<comments>http://www.depesz.com/2009/12/23/waiting-for-8-5-conditional-triggers/#comments</comments>
		<pubDate>Wed, 23 Dec 2009 02:50:19 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[cond]]></category>
		<category><![CDATA[conditional]]></category>
		<category><![CDATA[conditions]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[deferrable]]></category>
		<category><![CDATA[deferred]]></category>
		<category><![CDATA[pg85]]></category>
		<category><![CDATA[pg90]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[triggers]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1555</guid>
		<description><![CDATA[On 20th of November Tom Lane committed patch by Takahiro Itagaki which adds interesting functionality: Add a WHEN clause to CREATE TRIGGER, allowing a boolean expression to be checked to determine whether the trigger should be fired. &#160; For BEFORE triggers this is mostly a matter of spec compliance; but for AFTER triggers it can [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2009/12/23/waiting-for-8-5-conditional-triggers/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Waiting for 8.5 &#8211; better messages for unique violation</title>
		<link>http://www.depesz.com/2009/08/12/waiting-for-8-5-better-messages-for-unique-violation/</link>
		<comments>http://www.depesz.com/2009/08/12/waiting-for-8-5-better-messages-for-unique-violation/#comments</comments>
		<pubDate>Wed, 12 Aug 2009 09:02:58 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[index]]></category>
		<category><![CDATA[messages]]></category>
		<category><![CDATA[pg85]]></category>
		<category><![CDATA[pg90]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[unique]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1475</guid>
		<description><![CDATA[On 1st of August Tom Lane committed patch from Itagaki Takahiro: Improve unique-constraint-violation error messages to include the exact values being complained of. &#160; In passing, also remove the arbitrary length limitation in the similar error detail message for foreign key violations. &#160; Itagaki Takahiro and later added an extension to it: Department of second [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2009/08/12/waiting-for-8-5-better-messages-for-unique-violation/feed/</wfw:commentRss>
		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>Waiting for 8.5 &#8211; deferrable uniqueness</title>
		<link>http://www.depesz.com/2009/08/11/waiting-for-8-5-deferrable-uniqueness/</link>
		<comments>http://www.depesz.com/2009/08/11/waiting-for-8-5-deferrable-uniqueness/#comments</comments>
		<pubDate>Tue, 11 Aug 2009 11:24:19 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[deferrable]]></category>
		<category><![CDATA[deferred]]></category>
		<category><![CDATA[pg85]]></category>
		<category><![CDATA[pg90]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[primary key]]></category>
		<category><![CDATA[unique]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1473</guid>
		<description><![CDATA[On 29th of July ( I know, there is a long backlog in waiting for 8.5 series. I&#8217;m working on it , Tom Lane committed patch by Dean Rasheed: Support deferrable uniqueness constraints. &#160; The current implementation fires an AFTER ROW trigger for each tuple that looks like it might be non-unique according to the [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2009/08/11/waiting-for-8-5-deferrable-uniqueness/feed/</wfw:commentRss>
		<slash:comments>6</slash:comments>
		</item>
		<item>
		<title>Waiting for 8.5 &#8211; pgsql: DROP IF EXISTS for columns and constraints.</title>
		<link>http://www.depesz.com/2009/07/22/waiting-for-8-5-pgsql-drop-if-exists-for-columns-and-constraints/</link>
		<comments>http://www.depesz.com/2009/07/22/waiting-for-8-5-pgsql-drop-if-exists-for-columns-and-constraints/#comments</comments>
		<pubDate>Wed, 22 Jul 2009 09:41:33 +0000</pubDate>
		<dc:creator>depesz</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[column]]></category>
		<category><![CDATA[conditional]]></category>
		<category><![CDATA[constraint]]></category>
		<category><![CDATA[ddl]]></category>
		<category><![CDATA[drop]]></category>
		<category><![CDATA[pg85]]></category>
		<category><![CDATA[pg90]]></category>
		<category><![CDATA[postgresql]]></category>
		<category><![CDATA[sql]]></category>

		<guid isPermaLink="false">http://www.depesz.com/?p=1467</guid>
		<description><![CDATA[On 205h of July Andrew Dunstan committed patch by Andres Freund : Log Message: ----------- DROP IF EXISTS for columns and constraints. Andres Freund. The functionality is self-explanatory, so let&#8217;s just show some usage examples: Test table: # create table test (a int4, b int4); CREATE TABLE Drop non-existing column old way: # alter table [...]]]></description>
		<wfw:commentRss>http://www.depesz.com/2009/07/22/waiting-for-8-5-pgsql-drop-if-exists-for-columns-and-constraints/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
	</channel>
</rss>

