> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mantrixflow.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ClickHouse and MySQL pipelines

> Build, run, and verify ClickHouse-to-MySQL, MySQL-to-ClickHouse, and ClickHouse-to-ClickHouse pipelines.

This guide covers the cross-connector routes that the ClickHouse source and
destination connector pair supports. Every route uses the same SQL-first
pipeline workflow used by PostgreSQL, MySQL, and MariaDB.

## Validated connector routes

The following routes were exercised through the MantrixFlow browser workflow
with real source previews and destination verification:

| Source     | Destination | Result |
| ---------- | ----------- | ------ |
| ClickHouse | PostgreSQL  | Passed |
| ClickHouse | MySQL       | Passed |
| ClickHouse | MariaDB     | Passed |
| PostgreSQL | ClickHouse  | Passed |
| MySQL      | ClickHouse  | Passed |
| MariaDB    | ClickHouse  | Passed |
| ClickHouse | ClickHouse  | Passed |

This is a functional verification matrix, not a throughput benchmark.
Validate the matrix on your own clusters before promoting it to production.

## Required access

### Source access

The source user needs read-only access to the source tables. See the
[ClickHouse source connection guide](/connections/sources/database/clickhouse)
for the canonical `mantrixflow_reader` setup.

For PostgreSQL, MySQL, and MariaDB sources, use the dedicated reader
profile documented in the respective source guides.

### Destination access

The destination user needs write access to the destination database and
tables. See the
[ClickHouse destination connection guide](/connections/destinations/clickhouse)
for the canonical `mantrixflow_writer` setup.

For PostgreSQL, MySQL, and MariaDB destinations, grant `SELECT`, `INSERT`,
and `UPDATE` on the destination schema. Add `CREATE`, `ALTER`, and `DROP`
only when the destination editor is allowed to reconcile tables.

## ClickHouse cross-connector setup

For ClickHouse sources, configure the connection with **Secure / TLS**
enabled for cloud and remote deployments. The HTTP port defaults to
`8443` and the native port to `9440`. The HTTP port is the transport used
by the source extractor and the destination loader. The native port is the
transport used by the dlt ClickHouse destination's native protocol.

For ClickHouse destinations, the destination loader needs both ports. Use
the secure defaults for ClickHouse Cloud and the plain defaults for local
development.

## Full Table flow

The Full Table flow mirrors the rest of the platform:

1. Open **Connections** and create both the source and destination
   connections.
2. Open **Pipelines** and click **+ New Pipeline**.
3. Choose the source connection and select one or more tables.
4. Choose the destination connection and enter the published output
   target.
5. Open **Transformations** and create a SQL model that maps the source
   columns to the destination columns.
6. Save, validate, preview, and publish the revision.
7. Run the pipeline once and verify the **rows written** value against the
   destination count.

## Incremental flow

Incremental flows use a stable cursor on the source side and a stable
Upsert key on the destination side:

1. Choose the same source connection and select one or more tables.
2. Choose the destination connection and select the stable primary or
   unique key.
3. Set the source sync mode to **Incremental** and pick the cursor column.
4. Save, validate, preview, and publish the revision.
5. Run the pipeline twice and confirm that the second run only delivers
   the delta.

## Verify rows after the run

Use the same verification queries in the
[ClickHouse destination guide](/connections/destinations/clickhouse) and
the equivalent queries for the destination database. The duplicate query
should return no rows after the second run.

## Troubleshooting

* **Connection refused:** verify host, HTTP port, network allowlist, and
  firewall rules.
* **Authentication failed:** verify username, password, and database name.
* **TLS connection failure:** check the **Secure / TLS** toggle and the
  HTTP port. For self-hosted ClickHouse on TLS, ensure the certificate is
  trusted by the ELT runtime.
* **No tables discovered:** grant `SELECT` on the source schema and tables.
  System schemas are filtered out by design.
* **Duplicate destination rows:** use a stable primary key and Upsert
  delivery.
* **HTTP port mismatch:** update the **HTTP Port** field to match the
  listener. Use `8443` for secure cloud and `8123` for plain local.
* **Native port mismatch:** update the **Native Port** field to match the
  listener. Use `9440` for secure and `9000` for plain.

For a long-form connector reference, see the
[ClickHouse source guide](/connections/sources/database/clickhouse),
the
[ClickHouse destination guide](/connections/destinations/clickhouse),
and the
[PostgreSQL incremental example](/example/pipelines/postgres-incremental).