37 docs tagged with "getting-started"

Want to change the default value for new columns in ClickHouse? Here's how to do just that.

Want to explore local files in ClickHouse? Use clickhouse-local to run a temporary ClickHouse instance on your local machine to analyze structured files.

Want to apply a function to multiple columns in ClickHouse? Here's a shortcut to applying the same function across several columns in a table.

ClickHouse query logs growing too large? Here's how to apply a permanent TTL to your ClickHouse system.query_log.

Want to apply a default value to existing rows in a ClickHouse table column? Here's how to do that with MATERIALIZE.

Getting a TOO_MANY_PARTS exception in ClickHouse? If you see DB::Exception: Too many parts (600), you can avoid it by using async_insert in v21.11.

Want to change table TTLs in ClickHouse? Here's how you can modify the TTL of a table in ClickHouse and avoid impacting performance.

Want to know how to create a session when using the ClickHouse HTTP endpoint? Here's how to use the session_id parameter with ClickHouse.

Want to create a ClickHouse table from a remote file URL? You can use the `url` function to do that. Here's how.

ClickHouse usually processes queries very quickly, but here's how to track the progress of long-running ClickHouse queries.

Want to explore data using ClickHouse in the terminal? Here's how to do that with the clickhouse-client command line interface.

Want to export data from your existing ClickHouse instance to Tinybird's hosted ClickHouse? Here's how to do it.

Here's how you can discover which parts & partitions have been detached from your ClickHouse tables.

If you change a table in ClickHouse, it can affect Materialized Views that depend on it. Here's how to find all MV dependencies for your ClickHouse table.

Are your ClickHouse queries ugly? Here's how to format them in the command line with the ClickHouse query formatter.

ClickHouse servers can open network ports for TCP, HTTP, and gRPC. Here's how to find out which ports these interfaces are bound to on a ClickHouse server.

Want to get the latest ClickHouse build? Here's how to download the latest build to keep up with the many changes to ClickHouse.

Wondering what version of ClickHouse you're running? Here's how to get your ClickHouse version with a query, in the CLI, or over the HTTP interface.

ClickHouse doesn't perform overflow checks when casting between integer types. Here's how to handle integer overflows in ClickHouse with accurateCast.

Getting errors trying to cast toDateTime in ClickHouse? Use this ClickHouse function to handle most DateTime variations without throwing an exception.

Want to drop a table in ClickHouse without waiting until it's deleted? Here's how to use the SYNC modifier to drop tables synchronously in ClickHouse.

ClickHouse has many unique data types. Here's how to choose the right ones for your tables.

Wondering how to configure ClickHouse settings? Here are 5 tips to take into account when doing so.

Ever wondered how to share the same ClickHouse configuration between multiple servers locally? Here's how to do it.

Sometimes you want ClickHouse materialized views to behave like a typical RDBMS. Here's how to use Live Views to periodically refresh ClickHouse materializations.

Wondering how to monitor your ClickHouse server for new errors? Use the system.errors table to track all errors since the server started.

ClickHouse has functions to extract data from JSON strings, but what if you want to parse an array of JSON objects? Here's how.

Parsing URLs with SQL can be a pain. Here's how to use ClickHouse functions to work with URLs and avoid writing custom Regex.

Want to query from a specific part or partition of a ClickHouse table? Here's how to use ClickHouse virtual columns to do so.

Want to get data from multiple tables in ClickHouse with a single query? Use the merge() ClickHouse function instead of UNION ALL for cleaner queries.

Trying to debug a problem with your ClickHouse query, but having trouble filtering through the log file? Here's how to show logs in the CLI to reduce noise when debugging ClickHouse.

Want to drop a table in ClickHouse, but worried about losing data? Here's how to "soft" delete a ClickHouse table so you can restore it in the future.

Working with datetimes in ClickHouse? Here's how to subtract values from two DateTime64 columns in a ClickHouse table without getting an error.

Want to swap one table for another in ClickHouse? Here are two ways to swap tables in ClickHouse using EXCHANGE TABLE or RENAME TABLE statements

Trying to parse a specific ClickHouse error code? Here's how to view all error codes in ClickHouse.

ClickHouse stores intermediate aggregation states for materializations. Here's how to view intermediate states of aggregations and finalize aggregations.

Wondering the difference between the -If combinator and the WHERE statement in ClickHouse? Here are some guidelines to help you choose between -If and WHERE in ClickHouse.