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What is the advantage of maintaining an indexed database, with Foreign key and indexing of the most used fields as in searches?
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The difference can be analyzed using the explain.
try to query over a table, using a Where field. Then try putting an index in that field and pulling out, and seeing the differences. explain gives an explanation of what Mysql does when executing a query.
With the index, searches are accelerated, which only has a significant impact once these tables begin to have many records. The Foreign Keys have the same impact, and they also help in performance when making a Join between multiple tables.
In addition, the Foreign Keys allow you to define what should happen when you delete records from a given table, and your input is referenced in others. Lets you delete permissions from a given user if the permissions have a Foreign key for the user, and the corresponding user line is deleted.
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Related virtually duplicate (not because it has two questions in one): http://answall.com/q/35088/101 I voted to close as broad (if one would be duplicate, that’s the problem of broad question).
– Maniero
Related: When and in which columns should indexes be used?
– Jéf Bueno