DISTINCT ​

SELECT DISTINCT is used to select unique values from a set of data. This keyword returns distinct values from the output of the query.

The basic syntax for a SELECT DISTINCT statement is as followings:

SELECT DISTINCT idc
FROM system_metrics;

SELECT DISTINCT idc
FROM system_metrics;

SELECT DISTINCT can be used in conjunction with filters.

SELECT DISTINCT idc, host
FROM system_metrics
WHERE host != 'host2';

SELECT DISTINCT idc, host
FROM system_metrics
WHERE host != 'host2';

SELECT DISTINCT is a simple but powerful command of GreptimeDB SQL that allows users to easily condense the data into a summary of unique values. It can be used on one column or multiple columns, making it very versatile for data analysis and reporting. Using "SELECT DISTINCT" is a great way to get an overview of the types of data stored in the tables.