Re: With vs Without Primary Key in a particular case
It will have to read all the rows or all the values of the join column from one of the table and then try to find the matching value in the other table.
ALL and use index difference is that ALL will read all the data rows while use index will read from the index (MYI) without having to access the data (MYD). Either one will still read all the values from the 1st table.
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July 19, 2006 11:02PM
Re: With vs Without Primary Key in a particular case
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July 20, 2006 05:35PM
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