Comments on: MySQL Compression http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/ Just another Blogs.n1zyy.com weblog Wed, 07 Dec 2011 01:51:34 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: andrew http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/comment-page-1/#comment-2692 andrew Fri, 04 Dec 2009 19:23:32 +0000 http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/#comment-2692 Shaun: You're correct, the code as listed before was incorrect. I must have copied it over wrong. I've updated the post; thanks for commenting! Shaun: You’re correct, the code as listed before was incorrect. I must have copied it over wrong. I’ve updated the post; thanks for commenting!

]]> By: shaun http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/comment-page-1/#comment-2682 shaun Sat, 31 Oct 2009 20:11:59 +0000 http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/#comment-2682 This got me on the right track, but compress code needs to be the following to be compatible with MySQL UNCOMPRESS(): $compressed = pack('L', strlen($string)).gzcompress($string); This got me on the right track, but compress code needs to be the following to be compatible with MySQL UNCOMPRESS():

$compressed = pack(‘L’, strlen($string)).gzcompress($string);

]]> By: andrew http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/comment-page-1/#comment-1509 andrew Thu, 30 Jul 2009 17:51:25 +0000 http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/#comment-1509 Olaf, while that could cause issues for the code above, it only occurs if you're storing the compressed string in a CHAR or VARCHAR column. And the manual states: Use of nonbinary string data types such as CHAR or VARCHAR to store compressed strings is not recommended ... because character set conversion may occur. Use a VARBINARY or BLOB binary string column instead. We've definitely ran into problems where I work by storing compressed data in a VARCHAR column, so I'd personally reiterate their warning. Olaf, while that could cause issues for the code above, it only occurs if you’re storing the compressed string in a CHAR or VARCHAR column. And the manual states:

Use of nonbinary string data types such as CHAR or VARCHAR to store compressed strings is not recommended … because character set conversion may occur. Use a VARBINARY or BLOB binary string column instead.

We’ve definitely ran into problems where I work by storing compressed data in a VARCHAR column, so I’d personally reiterate their warning.

]]> By: Olaf http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/comment-page-1/#comment-1318 Olaf Mon, 13 Jul 2009 16:56:14 +0000 http://blogs.n1zyy.com/andrew/2007/06/30/mysql-compression/#comment-1318 What about the possible space character at the end of the uncompressed string? Mysql documentation says: "If the string ends with space, an extra “.” character is added to avoid problems with endspace trimming..." This will break in your case, wouldn't it? What about the possible space character at the end of the uncompressed string? Mysql documentation says: “If the string ends with space, an extra “.” character is added to avoid problems with endspace trimming…”

This will break in your case, wouldn’t it?

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