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MYSQL - Using Checksum with MYISAM Tables

Posted on 2006-11-17
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I am using mysql-4.0.24 on a Windows2000 machine for a small but complicated application. The number of queries and updates may be 50 or 60 per hour on days except Monday. On Monday's it could be around 100 to 150. All my tables are MYISAM with first 3 columns cross-indexed. The total number of tables in the database is 50. During each entry and update more than 5 or 6 tables are opened and closed multiple times. A few times I've experienced corruption of tables. Most of the times the error was -"can't open file: 'tableName.MYI'. (errno: 144)".
I've read somewhere that using CHECKSUM = 1 can reduce the chances of corruption in MYISAM tables. Is it correct? Will it affect the insert/update timing and query performance?
Regards
Thomas
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Question by:chasun
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Raynard7 earned 125 total points
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You are correct that this may reduce the corruption, however if this is happening regurlarly then there would be a greater underlying problem.  I know that this is an old version but still should not be happening.  I'd suggest that it is probably a hardware issue becuase this should not happen as a general rule.

It also may make things slower depending on the size of each table, becuase each change that is made a new checksum is generated - this involves looking at each byte in the file and then mathematically manipulating this to a signature.  If all your tables are reasonably small (100mb or so) then this should not greatly reduce performance.
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