Count table rows

Question

What is the MySQL command to retrieve the count of records in a table?

Answer 1

If you have a primary key or a unique key/index, the faster method possible (Tested with 4 millions row tables)

SHOW INDEXES FROM "database.tablename" WHERE Key_Name=\"PRIMARY\"

and then get cardinality field (it is close to instant)

Times where from 0.4s to 0.0001ms