What is Indexing? Indexing is a powerful structure in MySQL which can be leveraged to get the fastest response times from common queries. MySQL queries achieve efficiency by generating a smaller table, called an index, from a specified column or set of columns. These columns, called a key, can be used to enforce uniqueness. Below is a simple visualization of an example index using two columns as a key.
+------+----------+----------+ | ROW | COLUMN_1 | COLUMN_2 | +------+----------+----------+ | 1 | data1 | data2 | +------+----------+----------+ | 2 | data1 | data1 | +------+----------+----------+ | 3 | data1 | data1 | +------+----------+----------+ | 4 | data1 | data1 | +------+----------+----------+ | 5 | data1 | data1 | +------+----------+----------+