UNSUPPORTED_METHOD ClickHouse error

This error usually means you're trying to use a method or operation that isn't supported in ClickHouse. This can happen when using features from other database systems or unsupported ClickHouse functionality.

The UNSUPPORTED_METHOD error in ClickHouse (and Tinybird) happens when you try to use a method, operation, or feature that isn't supported by ClickHouse. This commonly occurs when using SQL features from other database systems or trying to use ClickHouse features that aren't available in your version.

What causes this error

You'll typically see it when:

  • Using MySQL or PostgreSQL specific features in ClickHouse
  • Trying to use unsupported ClickHouse features
  • Using deprecated or removed functionality
  • Attempting operations not supported by your ClickHouse version
  • Using client-specific methods that aren't available

Example errors

Fails: MySQL-specific feature
SELECT * FROM events LIMIT 10 OFFSET 20
Fails: unsupported operation
UPDATE events SET event_type = 'click' WHERE user_id = 123
Fails: unsupported method
SELECT * FROM events FOR UPDATE
Fails: unsupported operation
UPDATE events SET event_type = 'click' WHERE user_id = 123

How to fix it

Use ClickHouse-compatible syntax

Replace unsupported features with ClickHouse equivalents:

Fix: use ClickHouse pagination
SELECT * FROM events LIMIT 20 OFFSET 10

Use supported operations

Replace unsupported operations with supported alternatives:

Fix: use INSERT for updates
INSERT INTO events (user_id, event_type) VALUES (123, 'click')

Check ClickHouse documentation

Verify feature support in your ClickHouse version:

Check ClickHouse version
SELECT version()

Use alternative approaches

Find alternative ways to achieve the same result:

Fix: use INSERT for updates
INSERT INTO events (user_id, event_type) VALUES (123, 'click')

Common patterns and solutions

Pagination

ClickHouse pagination syntax:

Correct pagination
SELECT * FROM events ORDER BY timestamp DESC LIMIT 10 OFFSET 20

Data modification

ClickHouse doesn't support UPDATE/DELETE in the same way as other databases:

Alternative to UPDATE
-- Use INSERT with deduplication
INSERT INTO events_new SELECT * FROM events WHERE user_id != 123
INSERT INTO events_new (user_id, event_type) VALUES (123, 'click')

Joins

Supported join types in ClickHouse:

Supported joins
SELECT * FROM users INNER JOIN events ON users.id = events.user_id
SELECT * FROM users LEFT JOIN events ON users.id = events.user_id
SELECT * FROM users RIGHT JOIN events ON users.id = events.user_id
SELECT * FROM users FULL OUTER JOIN events ON users.id = events.user_id  -- Available in recent versions

Transactions

ClickHouse has limited transaction support:

ClickHouse transaction approach
-- Use atomic operations where possible
-- Consider using Materialized Views for complex updates

Advanced solutions

Using Materialized Views

For complex data modifications:

Materialized View for updates
CREATE MATERIALIZED VIEW events_updated AS
SELECT 
    user_id,
    CASE WHEN user_id = 123 THEN 'click' ELSE event_type END as event_type,
    timestamp
FROM events

Using INSERT with deduplication

For data replacement:

INSERT with deduplication
INSERT INTO events_new
SELECT 
    user_id,
    CASE WHEN user_id = 123 THEN 'click' ELSE event_type END as event_type,
    timestamp
FROM events

Using window functions

For complex aggregations:

Window functions for complex logic
SELECT 
    user_id,
    event_type,
    ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY timestamp) as row_num
FROM events

ClickHouse-specific features

Using ReplacingMergeTree

For handling updates:

ReplacingMergeTree example
CREATE TABLE events_replacing (
    user_id UInt32,
    event_type String,
    timestamp DateTime,
    version UInt32
) ENGINE = ReplacingMergeTree(version)
ORDER BY (user_id, timestamp)

Using CollapsingMergeTree

For handling deletes:

CollapsingMergeTree example
CREATE TABLE events_collapsing (
    user_id UInt32,
    event_type String,
    timestamp DateTime,
    sign Int8
) ENGINE = CollapsingMergeTree(sign)
ORDER BY (user_id, timestamp)

Tinybird-specific notes

In Tinybird, this error often occurs when:

  • Using unsupported ClickHouse features in Pipes
  • Trying to use features not available in Tinybird's ClickHouse version
  • Using client-specific methods that aren't supported
  • Working with Materialized Views that use unsupported operations

To debug in Tinybird:

  1. Check Tinybird's ClickHouse version and supported features
  2. Use the Query Builder to test operations
  3. Consult Tinybird documentation for supported features
  4. Use alternative approaches for unsupported operations

Tinybird doesn't allow updates/deletes on Data Sources. You must rebuild Data Sources or use Pipes for data transformations.

Best practices

Feature compatibility

  • Check ClickHouse documentation before using new features
  • Test operations in development environment first
  • Use version-specific feature checks
  • Keep up with ClickHouse updates and changes

Alternative approaches

  • Use Materialized Views for complex data modifications
  • Implement logic in application layer when needed
  • Use INSERT with deduplication for updates
  • Consider using specialized table engines

Error handling

  • Implement proper error handling for unsupported features
  • Have fallback approaches ready
  • Log unsupported method attempts
  • Document workarounds for common issues

See also