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Re: Calculate bytes stored per row for dynamic format
Posted by: Rick James
Date: July 05, 2012 06:00AM

I've seen a script; it is sometimes pasted into one of these forums. But it only handles INSERT-only MyISAM data, not DELETEs, not InnoDB, not INDEXes.

A simpler rule of thumb would be 100-1000 bytes per row per table. We got "up to 463" before accounting for updates and indexes. 100-1000 covers most variations except for big (BLOB, TEXT, etc) fields.

Is there some reason for using MyISAM? InnoDB is the preferred Engine.

DELETEs and UPDATEs complicate things because...
* UPDATE will (sort of, sometimes) delete the old row and add new row.
* DELETE leaves a gap in the table; this gap will be reused by future INSERT(s).
* The disk space for a table will not shrink. (See also OPTIMIZE, ALTER.)



Edited 1 time(s). Last edit at 07/05/2012 06:02AM by Rick James.

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