`information_schema.statistics.non_unique`

mysql

type: BIGINT NOT NULL

5.7-8

type: NULL

Note:

1 if the index can have duplicates, 0 if not.

5.1-10.8

type: BIGINT NOT NULL

Note:

1 if the index can have duplicates, 0 if not.

type: VARCHAR(1) NULL

Note:

If the index must not contain duplicate values, the value is 0; if duplicate values are allowed in the index, the value is 1.

4-6.1

type: unknown

Note:

NO if the index was created with the UNIQUE constraint; YES if the index was not created with UNIQUE.

2-21.2

Note:

false if the index was created by a Unique constraint; true if the index was not created by a Unique constraint.

1-1.1