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);
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);