How to perform a full-text phrase search in ClickHouse?

To perform full-text phrase search in ClickHouse, you can use the match() function in combination with regular expressions. Although ClickHouse does not have a built-in full-text search feature like some other databases, the match() function allows you to perform basic full-text search operations.

Here’s a simple example of how to perform a full-text phrase search using the match() function:

  1. First, let’s create a sample table:

CREATE TABLE documents
(
id UInt32,
content String
) ENGINE = MergeTree()
ORDER BY id;

2. Insert some sample data into the table:

INSERT INTO documents (id, content)
VALUES
(1, ‘The quick brown fox jumps over the lazy dog.’),
(2, ‘A journey of a thousand miles begins with a single step.’),
(3, ‘The only way to do great work is to love what you do.’);

3. Perform a full-text phrase search for the phrase “thousand miles”:

SELECT id, content
FROM documents
WHERE match(content, ‘thousand\\s+miles’);

In this query, we use the match() function to search for the phrase “thousand miles” in the content column. The regular expression ‘thousand\\s+miles’ searches for the word “thousand” followed by one or more whitespace characters (\s+) and then the word “miles”. The double backslashes (\) are used to escape the backslash character in the regular expression.

This query will return the following result:

┌─id─ ┬─content────────────────────────┐
│ 2. │ A journey of a thousand miles begins with a single step. └────┴─────────────────────────. ──┘

Keep in mind that this method of full-text phrase search is relatively simple and might not be suitable for large-scale or complex use cases. For advanced full-text search capabilities, you can consider integrating ClickHouse with an external search engine like Elasticsearch.

About Shiv Iyer 227 Articles
Open Source Database Systems Engineer with a deep understanding of Optimizer Internals, Performance Engineering, Scalability and Data SRE. Shiv currently is the Founder, Investor, Board Member and CEO of multiple Database Systems Infrastructure Operations companies in the Transaction Processing Computing and ColumnStores ecosystem. He is also a frequent speaker in open source software conferences globally.