Environment variables in clickhouse config

Question

Can we define separate parts of some tag in clickhouse config with environment variables?

For example we can use:

<engine from_env="ENGINE"/>

then all the value comes from env variable.

But can we use something like this:

<engine>ENGINE = MergeTree PARTITION BY ${PARTITIONING}
        ORDER BY (event_date, event_time)
        TTL ${TTL}
</engine>

Or is there some other option for this purpose?

Answer 1

You can use from_env for this. Eg:

<clickhouse>
<profiles>
    <default>
        <max_query_size from_env="MAX_QUERY_SIZE"/>
    </default>
</profiles>

Refer to Clickhouse doc here