Inserting Data into ClickHouse
You can use the familiar
INSERT INTO TABLE command with ClickHouse, but it is important to understand that each insert into a
MergeTree table causes a part to be created in storage. Even for a simple example, let's insert more than one row at a time:
INSERT INTO helloworld.my_first_table (user_id, message, timestamp, metric) VALUES
(101, 'Hello, ClickHouse!', now(), -1.0 ),
(102, 'Insert a lot of rows per batch', yesterday(), 1.41421 ),
(102, 'Sort your data based on your commonly-used queries', today(), 2.718 ),
(101, 'Granules are the smallest chunks of data read', now() + 5, 3.14159 )
- Notice the
timestampcolumn is populated using various Date and DateTime functions. ClickHouse has hundreds of useful functions that you can view in the Functions section.
Let's verify it worked - you should see the four rows of data that were inserted.
SELECT * FROM helloworld.my_first_table
If you need help inserting large datasets or encounter any errors when importing data into ClickHouse Cloud, please contact us at [email protected] and we can assist.
Insert large batches
Insert a large number of rows per batch - tens of thousands or even millions of rows at once. Inserting in batches optimizes for insert performance. Don't worry - ClickHouse can easily handle that type of volume!
If you can not insert a lot of rows at once and you are using an HTTP client, use the
async_insert setting, which batches your smaller inserts before inserting them into the table.
Integrating with ClickHouse
No matter where your data sits, there is likely a table function, table engine, or other type of tool available to insert your data into ClickHouse. Check out our Integrations page for more details.