hetu-core/hetu-docs/en/sql/show-stats.md

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Markdown

SHOW STATS
==========
Synopsis
--------
``` sql
SHOW STATS FOR table
SHOW STATS FOR ( SELECT * FROM table [ WHERE condition ] )
```
Description
-----------
Returns approximated statistics for the named table or for the results of a (limited) query.
Statistics are returned for each column, along with a summary row.
| Column | Description |
| ------------------------- | --------------------------------------- |
| `column_name` | The name of the column (`NULL` for the summary row)|
| `data_size` | The total size in bytes of all of the values in the column|
| `distinct_values_count` | The number of distinct values in the column|
| `nulls_fractions` | The portion of the values in the column that are `NULL`|
| `row_count` | The number of rows (only returned for the summary row)|
| `low_value` | The lowest value found in this column (only for some types)|
| `high_value` | The highest value found in this column (only for some types)|