RE: Speeding UNION with merging indexes

Hi, In the example you gave, it seems that MySQL doesn't merge the index of t1 in both sub-queries (which is the same index).. but it runs the sub-queries seperatedly, using the index on each sub-query seperatedly.. Mabye I wasn't clear enough with my question.. let me phrase it again: Say I

Re: Speeding UNION with merging indexes

ideas? Shawn Green Database Administrator Unimin Corporation - Spruce Pine Eli Hen [EMAIL PROTECTED] wrote on 08/03/2005 04:44:55 PM: Hi, In the example you gave, it seems that MySQL doesn't merge the index of t1 in both sub-queries (which is the same index).. but it runs the sub-queries

Speeding UNION with merging indexes

Hello, MySQL implemented index_merge in version 5... Does MySQL supports something like index_merge to speed up UNION queries? If yes, for which version (assumed release time)? Does anyone know of other DBs systems that can speed up UNION queries? This issue is quite critical for our system..

Re: Fulltext creation on 4.1: ERROR 1034

Kurt Haegeman [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Sergei Golubchik wrote: Hi! On Jan 13, Kurt Haegeman wrote: Hi, When trying to create a fulltext index on my large table, I get the following error: ERROR 1034 (HY000): 121 when fixing table Hi Sergei,

checking that any element from one group appears in another group?

Hello All, In MySQL it is possible to check if an element is existing in a group, like: ... WHERE 'a' IN ('a','b','c','d') ... but that checks one element only. I want to check if any element from a group exists in another group, like: ... WHERE ('a','f','g') IN ('a','b','c','d') ... 'a' in

REGEXP or LIKE

Hello, With your experience.. which runs better: REGEXP or LIKE? assuming you can express the query in both forms. I found that LIKE is twice faster than REGEXP using i.e: LIKE '%1068812942%' REGEXP '1068812942' -thanks, Eli -- MySQL General Mailing List For list archives:

Re: Multiple Roles

Caroline Jen [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] In case that a user has multiple roles; for example, John Dole is both author and editor, 1. I should have two rows for John Dole? John Dole author John Dole editor or. I should have only one row and

InnoDB size against MyISAM size

Hello, My HDD is running low and I MyISAM tables are keep crashing... I think that converting to InnoDB will be more stable, but what about the data files sizes? convertion to InnoDB will need more or less disk space than MyISAM? -thanks, Eli -- MySQL General Mailing List For list archives: