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what is Cardinality and Collation means ?

Posted: Wed Jun 25, 2008 5:13 am
by madan koshti
what is mean by mysql table Cardinality and Collation ?

Re: what is Cardinality and Collation means ?

Posted: Wed Jun 25, 2008 5:43 am
by Eran
A collation is a set of rules for comparing characters in a character set. http://dev.mysql.com/doc/refman/5.0/en/ ... neral.html
Cardinality is a measure of uniqueness for data in a row. It represents how different the rows in your table are from each other. http://en.wikipedia.org/wiki/Cardinalit ... tatements)

Re: what is Cardinality and Collation means ?

Posted: Wed Jun 25, 2008 6:00 am
by madan koshti
pytrin wrote:A collation is a set of rules for comparing characters in a character set. http://dev.mysql.com/doc/refman/5.0/en/ ... neral.html
Cardinality is a measure of uniqueness for data in a row. It represents how different the rows in your table are from each other. http://en.wikipedia.org/wiki/Cardinalit ... tatements)
What is mean by cardinality in integer value ?
e.g:
cardinality 5
cardinality 7
cardinality 10 etc... ?

Re: what is Cardinality and Collation means ?

Posted: Wed Jun 25, 2008 7:42 am
by Eran
It means how many unique rows you have in your table (according to the primary key)

Re: what is Cardinality and Collation means ?

Posted: Thu Jun 26, 2008 7:27 am
by madan koshti
pytrin wrote:It means how many unique rows you have in your table (according to the primary key)

Hey Thanks..............