Starting MySQL 4.1, MySQL had support for what is called derived tables, inline views or basically subselects in the from clause. In MySQL… instead of derived tables If you really need to use subselect in from clause consider creating view using it in the… it is pretty annoying gotcha which I hope MySQL will fix in next MySQL versions – the fact queries in this example behave…
Comment: Air traffic queries in InfiniDB: early alpha
November 3, 2009 By 19 Comments
… way to support the maximum amount of syntax for existing MySQL installations. We have observed that it performs reasonably well up…: At the moment, infinidb is not currently integrated with the MySQL information schema and we currently report 2000 rows for every… this is meaningful information for folks. subselects: Yes, you are correct, we currently do not support subselect. As Robin mentioned in a…
Comment: 7 Reasons why MySQL Quality will never be the same
December 11, 2008 By 15 Comments
… have Subselects and prepared statements fixed for next release rather than adding more half baked features. The manor features in MySQL 4.1 were Subselects, Prepared Statements and Character Sets. All they were not done by Monty and these were changes which MySQL… trivial cases and still have serve performance limitations as of MySQL 5.1 (so many years and releases away). Prepared statements…
Comment: Derived Tables and Views Performance
September 1, 2006 By 16 Comments
… it to use TEMPTABLE for query execution. See http://dev.mysql.com/doc/refman/5.0/en/create-view.html Regarding… based on real production cases. Note: It applies to subselects in FROM clause only. Other kind of subselects is very different story.
Comment: MySQL - to use or not to use
May 31, 2007 By 10 Comments
… projects when MySQL works great. MySQL can be made to work in many cases when complex reporting queries is needed as MySQL often fails to optimize subselects properly… all together ? People which were raised on MySQL typically choose to stick to MySQL and find workarounds, in case application is portable…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
… Operating Mode (infinidb_vtable_mode). mysql> show warnings; +——-+——+————————————————————+ | Level | Code | Message | +——-+——+————————————————————+ | Error | 9999 | Subselect in From clause is not…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… by people with traditional database background. > Things are different with MySQL. Good design will help dictate how many tables are required… problems with loosing data etc. Read more in my > Why MySQL Could be slow with Large Tables article. Deciding whether or… queries in this case. > This most applies to subqueries Where Subselects with IN() become > corellated even if they are not, and…
Comment: Using delayed JOIN to optimize count(*) and LIMIT queries
April 9, 2007 By 22 Comments
… from using 2 subselects in FROM clause and joining them together. The problem is however in this case MySQL will not be… can kill performance. In such case one can use old MySQL 4.0 way and create one of the result set…
Post: Feature Idea: Finding columns which query needs to access
November 17, 2006 By 16 Comments
… to mention more complex questions of subselects. It would be great tool for MySQL Performance Optimization if MySQL Server could show this table…
Comment: Using delayed JOIN to optimize count(*) and LIMIT queries
April 6, 2007 By 22 Comments
…in the future I hope MySQL Optimizer will be improved so it does these transformations automatically” … a temp table then join against that. This was before subselects… Even worse is that joins with blobs that are never…
