temp file error

kasturi

• July 26, 2011 00:00

• Answered

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I am trying to run a graph simply to extarct three columns from a table in MySql. The table has little over 4 million rows. I am getting this error. If I limit in 100000

Error writing file '/tmp/MYfS3dok' (Errcode: 28).

Thanks,
Kasturi

• 

  avackova

  • July 27, 2011 09:13

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  Hello Kasturi,
  MySQL can create large temporary files, when reading data from the database. This error points to a lack of disk space to be able to store the query results (see http://lists.mysql.com/mysql/214982).
  Following is the extract from the MySQL thread:
  

  • your tmp folder is limited - try to remove the limit or instruct MySQL to use different location: [list:3q5n92go][*:3q5n92go]Add the location to MySQL configuration file:

    [mysqld]
    tmpdir=/path/to/space

  [/*:m:3q5n92go]
  

  you can make MySQL to use memory for creating temp files rather than disk
  

  [*:3q5n92go] set sort_buffer_size=1024*1024*100

  [/*:m:3q5n92go]
  

  you have where or order by clause in your query but no index on the field(s) - the server must first sort all qualifying rows. This is where it needs so much space.

  [/list:u:3q5n92go]
• 

  kasturi

  • July 28, 2011 19:51

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  Agata,
  As always, thank you for your response. I really appreciate it.
  Regards,
  Kasturi

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