VARSAMP

Syntax

VARSAMP(expr)

Purpose

This function returns the sample variance of the expr expression.

Examples

1. Enable the ClickHouse extension function mode.

   obclient> ALTER SYSTEM SET sql_func_extension_mode = "ClickHouse";
   

2. Create a test table test_tbl1.

   obclient> CREATE TABLE test_tbl1 (col1 INT PRIMARY KEY, col2 VARCHAR(50), col3 INT);
   

3. Insert data into the test_tbl1 table.

   obclient> INSERT INTO test_tbl1 VALUES(1, 'a1', 6), (2, 'a2', 8), (3, 'a2', 10);
   

4. Use the VARSAMP function to calculate the variance of column col3.

   obclient> SELECT VARSAMP(col3) FROM test_tbl1;
   

   The return result is as follows:

   +---------------+
   | VARSAMP(col3) |
   +---------------+
   |             4 |
   +---------------+
   1 row in set