FETCH COLUMN HISTOGRAM¶

This command displays the results of an ANALYZE TABLE operation.

More about statistics under Cost-Based Optimizer

Syntax¶

SELECT FETCH_COLUMN_HISTOGRAM('<table_name>', '<column_name>')

Parameters¶

Parameter	Description	Parameter Type
`table_name`	Identifier	Identifies the table for which to apply statistics
`column_name`	Identifier	Identifies the column for which to apply statistics

Usage Note¶

The Statistics operation does not support the following column data types:

TEXT
NUMERIC

Examples¶

When querying for statistics of a specific column, note that for nullable columns, it’s required to specify that you’re querying for values using the @val suffix.

SELECT FETCH_COLUMN_HISTOGRAM("nba", "number");

-- Using the @val suffix:
SELECT FETCH_COLUMN_HISTOGRAM("nba", "number@val");

If the operation hasn’t finished yet, the output will indicate that Column has no statistics:

info                    |
------------------------+
Column has no statistics|

If the operation has finished, the output will show the requested histogram:

BucketLeft|BucketRight|BucketCount|
----------+-----------+-----------+
         0|          0|          2|
         1|          1|          2|
         3|          3|          2|
         7|          7|          1|
        12|         12|          1|
        13|         13|          1|
        23|         23|          1|
        24|         24|          1|
        35|         35|          1|

Permissions¶

The role must have the SUPERUSER permissions.