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indexing - What is the significance of the index name when creating an index in MySQL?

I've done something like this in order to use on duplicate key update:

CREATE UNIQUE INDEX blah on mytable(my_col_to_make_an_index);

and its worked just fine. I'm just not sure what the purpose of the index name is -- in this case 'blah'. The stuff I've read says to use one but I can't fathom why. It doesn't seem to be used in queries, although I can see it if I export the schema.

So ... what purpose does the index name serve? If it helps the line in the CREATE TABLE ends up looking like:

UNIQUE KEY `clothID` (`clothID`)
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The index name is used to reference the index for future commands. Like drop index.

http://dev.mysql.com/doc/refman/5.0/en/drop-index.html

Just think of index names like table names. You can just as easily make a table called 'blah'.

CREATE TABLE blah (f1 int);

But 'blah' isn't very helpful for future reference. Just be consistent. something like

CREATE UNIQUE INDEX field_uniq on mytable(field);

or

CREATE INDEX field1_field2_inx on mytable(field1, field2);

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