Comments on: Using CHAR keys for joins, how much is the overhead ? http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/ Percona's MySQL & InnoDB performance and scalability blog Sat, 11 Feb 2012 16:45:54 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: links for 2008-10-23 « Object neo = neo Object http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-364627 links for 2008-10-23 « Object neo = neo Object Fri, 24 Oct 2008 04:30:39 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-364627 [...] Using CHAR keys for joins, how much is the overhead ? | MySQL Performance Blog (tags: uuid mysql) [...] [...] Using CHAR keys for joins, how much is the overhead ? | MySQL Performance Blog (tags: uuid mysql) [...]

]]> By: JOIN Performance & Charsets | MySQL Performance Blog http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-363682 JOIN Performance & Charsets | MySQL Performance Blog Tue, 21 Oct 2008 17:49:18 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-363682 [...] have written before about the importance of using numeric types as keys, but maybe you've inherited a schema that you [...] [...] have written before about the importance of using numeric types as keys, but maybe you’ve inherited a schema that you [...]

]]> By: Picking datatype for STATUS fields | MySQL Performance Blog http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-343051 Picking datatype for STATUS fields | MySQL Performance Blog Sun, 10 Aug 2008 06:30:51 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-343051 [...] row using 10 byte VARCHAR(10) will not waste too much space. The other problem you may run into is slower JOIN performance especially for MyISAM Tables. Though it is solvable as [...] [...] row using 10 byte VARCHAR(10) will not waste too much space. The other problem you may run into is slower JOIN performance especially for MyISAM Tables. Though it is solvable as [...]

]]> By: Peaceful Programmer » Blog Archive » Database Enlightenment: Indexes http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-338802 Peaceful Programmer » Blog Archive » Database Enlightenment: Indexes Fri, 01 Aug 2008 22:51:12 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-338802 [...] not the end of the world to de-naturalize a piece of data. Plus, not only is it okay, but there are significant benefits in speed and tool [...] [...] not the end of the world to de-naturalize a piece of data. Plus, not only is it okay, but there are significant benefits in speed and tool [...]

]]> By: Rakesh http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-190533 Rakesh Mon, 12 Nov 2007 09:54:32 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-190533 I believe this is true from across the database environments; be it MS-SQL or MySQL or ORACLE or DB2 or any other. I believe this is true from across the database environments; be it MS-SQL or MySQL or ORACLE or DB2 or any other.

]]> By: rafael http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-174038 rafael Mon, 01 Oct 2007 11:11:16 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-174038 how to convert MYSQL ENUM (char type) into ENUM (int type) how to convert MYSQL ENUM (char type) into ENUM (int type)

]]> By: Rob http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-144890 Rob Fri, 13 Jul 2007 10:35:46 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-144890 any Mysql Podcast other than She BA Podcast that are good? sorry this is off topic I know.... Cheers Rob any Mysql Podcast other than She BA Podcast that are good?
sorry this is off topic I know….

Cheers Rob

]]> By: Alexey http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-144279 Alexey Wed, 11 Jul 2007 05:37:53 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-144279 Is VARBINARY same as VARCHAR/binary? Is VARBINARY same as VARCHAR/binary?

]]> By: peter http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-142904 peter Thu, 05 Jul 2007 14:33:10 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-142904 Pajz, I'm not sure what is the point of this documentation quote. But regarding memory - there is enough memory to fit all database in all cases so disk IO is not an issue here. Pajz,

I’m not sure what is the point of this documentation quote.
But regarding memory – there is enough memory to fit all database in all cases so disk IO is not an issue here.

]]> By: Pajz http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/comment-page-1/#comment-142857 Pajz Thu, 05 Jul 2007 08:36:18 +0000 http://www.mysqlperformanceblog.com/2007/06/18/using-char-keys-for-joins-how-much-is-the-overhead/#comment-142857 Hi Peter may be your computer has low memory. This comment is base in My SQL documenration try again to retreive the data.. Before MySQL 5.0.3, a CHAR or VARCHAR column with a length specification greater than 255 is converted to the smallest TEXT type that can hold values of the given length. For example, VARCHAR(500) is converted to TEXT, and VARCHAR(200000) is converted to MEDIUMTEXT. Similar conversions occur for BINARY and VARBINARY, except that they are converted to a BLOB type Hi Peter may be your computer has low memory.
This comment is base in My SQL documenration try again to retreive the data..

Before MySQL 5.0.3, a CHAR or VARCHAR column with a length specification greater than 255 is converted to the smallest TEXT type that can hold values of the given length. For example, VARCHAR(500) is converted to TEXT, and VARCHAR(200000) is converted to MEDIUMTEXT. Similar conversions occur for BINARY and VARBINARY, except that they are converted to a BLOB type

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