About Can Sayn
Can Sayın is experienced Database Administrator in open source relational and NoSql databases, working in complicated infrastructures. Over 5 years industry experience, he gain managing database systems. He is working at ChistaDATA Inc. His areas of interest are generally on open source systems.
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Check Queries That Being Processed In ClickHouse

Following sql query will show you queries that being processed. SELECT user, address as client, elapsed as time_seconds, formatReadableSize(memory_usage) as memory, formatReadableSize(read_bytes) as read, read_rows, total_rows_approx as total_rows, query_id, substring(query,1,40) as query FROM system.processes ORDER […]

Maximizing Performance With ClickHouse Index Granularity

In the world of data analytics and storage, databases are the backbone that supports businesses’ decision-making processes. ClickHouse, an open-source columnar database management system, has gained popularity for its exceptional speed and efficiency in handling […]

Removing Empty Parts In ClickHouse

The new feature of empty part removal was introduced in version 20.12. If TTL removes all rows from a part, older versions leave empty parts (with 0 rows) (see https://github.com/ClickHouse/ClickHouse/issues/5491). If you establish a TTL […]

Check Current TTL Settings in ClickHouse

Run a query on system.parts to see the absolute TTL values for a particular piece of data. For each section, columns indicate any TTL restrictions that are currently in effect. SELECT * FROM system.parts WHERE […]

Time Zones In ClickHouse

DateTime in ClickHouse refers to the number of seconds since 1970-01-01 00:00:00 GMT or UNIX timestamp. Both on the server (for HTTP clients and certain types of queries, such toString(ts)) and on the client (for […]

ClickHouse June 2023 Release – Version 23.6

Every new release includes new features, enhancements, and numerous bug fixes, and the ChistaDATA team always stays on top of the latest releases. On June 01, 2023, ClickHouse version 23.06 was released, and this version […]

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