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MySQL 5.7 Reference Manual  / ...  / MySQL sys Schema  / sys Schema Object Reference  / sys Schema Views  /  The schema_redundant_indexes and x$schema_flattened_keys Views

26.4.3.27 The schema_redundant_indexes and x$schema_flattened_keys Views

Theschema_redundant_indexes view displays indexes that duplicate other indexes or are made redundant by them. Thex$schema_flattened_keys view is a helper view forschema_redundant_indexes.

In the following column descriptions, the dominant index is the one that makes the redundant index redundant.

Theschema_redundant_indexes view has these columns:

  • table_schema

    The schema that contains the table.

  • table_name

    The table that contains the index.

  • redundant_index_name

    The name of the redundant index.

  • redundant_index_columns

    The names of the columns in the redundant index.

  • redundant_index_non_unique

    The number of nonunique columns in the redundant index.

  • dominant_index_name

    The name of the dominant index.

  • dominant_index_columns

    The names of the columns in the dominant index.

  • dominant_index_non_unique

    The number of nonunique columns in the dominant index.

  • subpart_exists

    Whether the index indexes only part of a column.

  • sql_drop_index

    The statement to execute to drop the redundant index.

Thex$schema_flattened_keys view has these columns:

  • table_schema

    The schema that contains the table.

  • table_name

    The table that contains the index.

  • index_name

    An index name.

  • non_unique

    The number of nonunique columns in the index.

  • subpart_exists

    Whether the index indexes only part of a column.

  • index_columns

    The name of the columns in the index.