clickhouse

The datasource.clickhouse module allows make queries to a Clickhouse cluster

Usage:

script.lua

local db = require('datasource.clickhouse.<NAME_FROM_CONFIG>')

Methods

query

query('<SQL QUERY>') result, error

Send a query. If an error occurred, it will be returned as second value

A result format:

{
    -- row 1
    {
        <FIELD1_NAME> = <FIELD1_VALUE>,
        <FIELD2_NAME> = <FIELD2_VALUE>,
        ...
    },
    -- row 2
    {
        <FIELD1_NAME> = <FIELD1_VALUE>,
        <FIELD2_NAME> = <FIELD2_VALUE>,
        ...
    },
    -- row N
    ...
}

An example:

script.lua

local db = require('datasource.clickhouse.dev')

local res, err = db.query("SELECT table, sum(bytes) AS size FROM system.parts WHERE active AND database = 'system' GROUP BY table")
if err ~= nil then
    return
end

-- res 
{
    {
        table = 'query_thread_log',
        size = 943846427
    },
    {
        table = 'metric_log',
        size = 656645852
    },
    {
        table = 'query_log',
        size = 997251520
    },
    {
        table = 'part_log',
        size = 2037035728
    }
}