# OPTIMIZER\_STATISTICS

This view contains [column statistics](https://docs.singlestore.com/db/v9.1/query-data/query-tuning/statistics-and-sampling/statistics-and-sampling-tasks.md) calculated on columns when a table is processed by autostats or the `ANALYZE` command.

It displays one row per column per table. The values displayed here are estimates used for query optimization, they are not exact.

| Column Name             | Description                                                                                          |
| ----------------------- | ---------------------------------------------------------------------------------------------------- |
| `DATABASE_NAME`         | The name of the related database.                                                                    |
| `TABLE_NAME`            | The name of the related table.                                                                       |
| `COLUMN_NAME`           | The name of the related column.                                                                      |
| `ROW_COUNT`             | The number of rows in a given table.                                                                 |
| `NULL_COUNT`            | The number of`null`values stored within a given column.                                              |
| `CARDINALITY`           | The number of unique values stored within a given column.                                            |
| `AUTOSTATS_ENABLED`     | Whether or not autostats are currently enabled for a given column.                                   |
| `AUTOSTATS_OUTDATED`    | Whether or not autostats are considered too out-of-date to be used currently.                        |
| `AUTOSTATS_ROW_COUNT`   | This column is deprecated and no longer used and its value is always`NULL`. See`ROW_COUNT`instead.   |
| `AUTOSTATS_NULL_COUNT`  | This column is deprecated and no longer used and its value is always`NULL`. See`NULL_COUNT`instead.  |
| `AUTOSTATS_CARDINALITY` | This column is deprecated and no longer used and its value is always`NULL`. See`CARDINALITY`instead. |
| `ADVANCED_HISTOGRAMS`   | Whether advanced histograms are collected on this column.                                            |
| `LEGACY_HISTOGRAMS`     | Whether legacy histograms are collected on this column. This column is now deprecated.               |
| `RANGE_STATS`           | Whether histograms (of either type) are collected on this column .                                   |
| `SAMPLE_SIZE`           | The sample size collected to build histograms on this column.                                        |
| `LAST_UPDATED`          | The timestamp at which autostats were last updated for a given column.                               |

***

Modified at: August 29, 2022

Source: [/db/v9.1/reference/information-schema-reference/query-performance-workload-management-and-statistics/optimizer-statistics/](https://docs.singlestore.com/db/v9.1/reference/information-schema-reference/query-performance-workload-management-and-statistics/optimizer-statistics/)

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