Is MySQL going invisible? Invisible Indexes were included in MySQL 8.0 and now with version 8.0.23 we have Invisible Columns.
Indexes You Can Not See!
The value of the invisible index is that it allows you to make an index disappear from the view of the optimizer. In the distant days before 8.0, you would often delete an index you were pretty much definitively positive nobody or no query was using. And then you would find out that yes, not only was that index you just deleted necessary to everyone in the galaxy (but maybe you) but it was going to take some serious clock time to rebuild that index.
But with Invisible Indexes, you issue a command like ALTER TABLE t1 ALTER INDEX i_idx INVISIBLE; and it was removed from use. Now you can run EXPLAIN on your queries and compare results. And if you want that index back among the visible, ALTER TABLE t1 ALTER INDEX i_idx …
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