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| bio | website | |
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| location | ||
| age | ||
| visits | member for | 2 years, 4 months |
| seen | 10 hours ago | |
| stats | profile views | 25 |
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May 19 |
awarded | Caucus |
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Feb 14 |
awarded | Yearling |
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Jan 23 |
comment |
Best book on query optimization, rewriting, refactoring Books about optimizations I liked are "The Art of SQL" by Stephane Faroult and Peter Robson (not specific for PostgreSQL, but it's exactly about what you want) and "PostgreSQL 9.0 High Performance" by Gregory Smith. |
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Sep 14 |
awarded | Popular Question |
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Aug 17 |
awarded | Citizen Patrol |
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Aug 10 |
comment |
Can spatial index help a “range - order by - limit” query About "Covering indexes" in PostgreSQL see also Erwin Brandstetter's comment to the question. |
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Aug 7 |
comment |
Can spatial index help a “range - order by - limit” query If you had many updates, the nested set model would be a bad choice with respect to performance (if you have access to the book "The art of SQL", take a look at the chapter about hierachic models). But anyway, your main problem is similar to finding the maximum/the highest values (of an independent variable) on an interval, for which it is hard to design an indexing method. To my knowledge, the closest match to the index you need is the knngist module, but you would have to modify it to fit your needs. A spatial index is unlikely to be helpful. |
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Aug 7 |
comment |
Can spatial index help a “range - order by - limit” query OK, I asked to see if using an alternative to the nested set model might be profitable (according to your response probably not). |
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Aug 7 |
comment |
Can spatial index help a “range - order by - limit” query Two questions: (1) What kind of usage pattern do you expect for the table? Are there mostly reads or are there frequent updates (especially of the nested set variables)? (2) Is there any connection between the nested set integer variables lset and rset and the text variable word? |
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Jun 19 |
awarded | Enthusiast |
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Jun 8 |
awarded | Caucus |
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Feb 10 |
comment |
Postgres Index scan forward vs backward = speed difference of 357X slower Do you have NULLs in the shareschange column? If yes (and lots of them), then use a partial index on the non-NULL elements only. |
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Feb 10 |
comment |
Ways to speed up IN queries under PostgreSQL Where do these long lists of id's come from? Are they stored/calculated outside of the database? |
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Jan 17 |
comment |
PostgreSQL vs. MySQL - Advantages / Disadvantages with a spatial component In case you have not seen it, there is a similar question on slashdot that will probably get more attention. |
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Jan 7 |
comment |
Configuring PostgreSQL for write performance Another excellent resource for these kind of questions is Gregory Smith's book PostgreSQL 9.0 High Performance. |
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Dec 20 |
comment |
PostgreSQL and query planner Also +1 for PostgreSQL High Performance. Great book, thanks! |
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Oct 20 |
comment |
Pioneers in Database Research I wonder why the Codd's entry on wikipedia does not contain "The Key, The Whole Key, and Nothing but the Key, so help me Codd". |
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Sep 15 |
comment |
Writing a simple bank schema: How should I keep my balances in sync with their transaction history? If you choose option 2 (which I think is cleaner), take a look at pgcon.org/2008/schedule/attachments/… how to implement "materialized views" efficiently. For option 1, chapter 11 of Haan's and Koppelaars' Applied Mathematics for Database Professionals (don't worry about the title) would be helpful to get an idea how to implement "transition constraints" efficiently. The first link is for PostgreSQL and the second for Oracle, but the techniques should work for any reasonable database system. |
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May 15 |
comment |
Indexing to improve performance of range queries @JackPDouglas: Your first sentence is not correct. Postgresql (at least Version 8.1 and up) is able to combine two different indexes using a bitmap index scan (see en.wikipedia.org/wiki/Bitmap_index#In-memory_bitmaps) |
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Apr 12 |
revised |
Postgres, MVCC, and Locking added comment about Advisory Locks |
