# MV\_QUERY\_COLUMN\_USAGE

This view provides information about the usage of columns by queries in the workload.

Details about column that are used in joins, filters, group-bys, order-bys or reshuffles help to understand the frequency and cost of use of columns, and make better decisions about indexing and sharding of data.

| Column name        | Description                                                                                                    |
| ------------------ | -------------------------------------------------------------------------------------------------------------- |
| `activity_name`    | The ID associated with the query. This will be the`activity_name`of all query tasks associated with the query. |
| `database_name`    | The name of the database, or`NULL`if none could be assigned.                                                   |
| `table_name`       | The name of the table in the query.                                                                            |
| `column_name`      | The name of the column that exists in the table.                                                               |
| `equijoins`        | The number of times this column was involved in an equijoin in the query.                                      |
| `non_equijoins`    | The number of times the column was involved in a non-equijoin in the query.                                    |
| `equality_preds`   | The number of times the column was involved in equality predicates in the`WHERE`or`ON`clause in the query.     |
| `inequality_preds` | The number of times the column was involved in inequality predicates in the`WHERE`or`ON`clause in the query.   |
| `groupbys`         | The number of times the column was involved in a`GROUP BY`clause in the query.                                 |
| `orderbys`         | The number of times the column was involved in a`ORDER BY`clause in the query.                                 |
| `reshuffles`       | The number of times the column was member of reshuffle key in the query.                                       |
| `outputs`          | The number of times the column was returned as the result of the query.                                        |

***

Modified at: August 29, 2022

Source: [/db/v9.1/reference/information-schema-reference/management/mv-query-column-usage/](https://docs.singlestore.com/db/v9.1/reference/information-schema-reference/management/mv-query-column-usage/)

(An index of the documentation is available at /llms.txt)