[prev in list] [next in list] [prev in thread] [next in thread] 

List:       mysql
Subject:    Efficient Blobbing?
From:       "Felix E. Klee" <felix.klee () inka ! de>
Date:       2011-01-06 17:12:28
Message-ID: AANLkTim2_yq=Dg7hhTa5QethbGhNU=waHeQ++F7iXY5s () mail ! gmail ! com
[Download RAW message or body]

I am dealing with blobs up to - I estimate - about 100 kilo bytes in
size.

Storage engine: InnoDB

Frontend: PHP

Some questions:

* I've read somewhere that it's not good to update blobs, because it
 leads to reallocation, thus fragmentation, thus bad performance. Is
 that true? Any reference on this?

* Initially the blobs get constructed by appending data chunks. Each
 chunk is up to 16 kilo bytes in size. Is it more efficient to use a
 separate chunk table instead, for example with fields as below?

   parent_id, position, chunk

 Then, to get the entire blob, one would do something like:

   SELECT GROUP_CONCAT(chunk ORDER BY position) FROM chunks WHERE
   parent_id = 187

 The result would be used in a PHP script.

* Is there any difference between the types of blobs, aside from the
 size needed for meta data, which should be negligible.

-- 
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:    http://lists.mysql.com/mysql?unsub=mysql-marcsub@progressive-comp.com

[prev in list] [next in list] [prev in thread] [next in thread]