Обсуждение: Hypothetical Indexes - PostgreSQL extension - PGCON 2010
<pre><font size="2">Hackers,<br /><br />We would like to inform you all that our extension to PostgreSQL, that includes hypotheticalindexes (and soon index self-tuning), is available through a sourgeforge project. <br />This was suggested atPgCon 2010 and we hope some of you may find it useful, contribute and give us your feedback.<br /> <br />Link to project: </font><br /><font color="#ff0000"><a href="http://sourceforge.net/projects/hypotheticalind/" target="_blank">http://sourceforge.net/projects/hypotheticalind/</a></font><br /><br />Thanks,<br />Sergio Lifschitz<br /> Ana Carolina Almeida<br /></pre>
Ana,
> We would like to inform you all that our extension to PostgreSQL, that includes hypothetical indexes (and soon index
self-tuning),is available through a sourgeforge project.
> This was suggested at PgCon 2010 and we hope some of you may find it useful, contribute and give us your feedback.
Great to see this being available finally!
-- -- Josh Berkus PostgreSQL Experts Inc.
http://www.pgexperts.com
On 2010-12-02 00:48, Ana Carolina Brito de Almeida wrote: > We would like to inform you all that our extension to PostgreSQL, that includes hypothetical indexes (and soon index self-tuning),is available through a sourgeforge project. > This was suggested at PgCon 2010 and we hope some of you may find it useful, contribute and give us your feedback. Looking at the sourceforge page, I'm left with one burning question: what are they for? I can see what a hypothetical index is, but neither the project pages nor the README in the tarball say why I might want one. I'd be quite interested to know that. Jeroen
On 03/12/10 08:14, Jeroen Vermeulen wrote: > On 2010-12-02 00:48, Ana Carolina Brito de Almeida wrote: > >> We would like to inform you all that our extension to PostgreSQL, that >> includes hypothetical indexes (and soon index self-tuning), is >> available through a sourgeforge project. > Looking at the sourceforge page, I'm left with one burning question: > what are they for? I believe they're for performance testing. Add hypothetical index (takes very little time). Check estimated costs with EXPLAIN. If good, add real index (takes lots of time). Of course, they're also good for indexing hypothetical data ;-) -- Richard Huxton Archonet Ltd
On 2010-12-03 19:44, Sergio Lifschitz wrote: > Indeed, hypothetical indexes are good to check potentially good > configurations without harming the whole system with actual index > creation. Please observer that we've added an "explain hypothetical" > command, that will include plans considering hypothetical indexes! We'll > try to add a simple case study that would help those wondering about > this project. That sounds very useful indeed! Jeroen
Jeroen,<br /><br />We add a simple case study (sourceforge page):<br /><a href="http://sourceforge.net/projects/hypotheticalind/files/TUTORIAL_8_4.pdf/download">http://sourceforge.net/projects/hypotheticalind/files/TUTORIAL_8_4.pdf/download</a><br /><br/><span class="long_text" id="result_box" lang="en"><span style="" title="">Although this tutorial is for version 8.4,it also applies to other versions.</span></span><br /><br />Att,<br />Ana Carolina<br /><br /><div class="gmail_quote">2010/12/3 Jeroen Vermeulen <span dir="ltr"><<a href="mailto:jtv@xs4all.nl">jtv@xs4all.nl</a>></span><br/><blockquote class="gmail_quote" style="border-left: 1px solidrgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">On 2010-12-03 19:44, Sergio Lifschitzwrote:<br /><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt0.8ex; padding-left: 1ex;"> Indeed, hypothetical indexes are good to check potentially good<br /> configurations withoutharming the whole system with actual index<br /> creation. Please observer that we've added an "explain hypothetical"<br/> command, that will include plans considering hypothetical indexes! We'll<br /> try to add a simple casestudy that would help those wondering about<br /> this project.<br /></blockquote><br /></div> That sounds very usefulindeed!<br /><font color="#888888"><br /><br /> Jeroen<br /></font></blockquote></div><br />
Indeed, hypothetical indexes are good to check potentially good configurations without harming the whole system with actual index creation. Please observer that we've added an "explain hypothetical" command, that will include plans considering hypothetical indexes! We'll try to add a simple case study that would help those wondering about this project. Sergio On 3/12/2010 08:06, Richard Huxton wrote: > On 03/12/10 08:14, Jeroen Vermeulen wrote: >> On 2010-12-02 00:48, Ana Carolina Brito de Almeida wrote: >> >>> We would like to inform you all that our extension to PostgreSQL, that >>> includes hypothetical indexes (and soon index self-tuning), is >>> available through a sourgeforge project. > >> Looking at the sourceforge page, I'm left with one burning question: >> what are they for? > > I believe they're for performance testing. Add hypothetical index > (takes very little time). Check estimated costs with EXPLAIN. If good, > add real index (takes lots of time). > > Of course, they're also good for indexing hypothetical data ;-) >
On 2010-12-03 20:49, Ana Carolina Brito de Almeida wrote: > We add a simple case study (sourceforge page): > http://sourceforge.net/projects/hypotheticalind/files/TUTORIAL_8_4.pdf/download Great, thanks! I'll try to write a bit more about it later: http://pqxx.org/development/libpqxx/wiki/HypotheticalIndexes Jeroen