# Limitations and considerations

The following limitations apply when using the Snowflake source endpoint in a Replicate task:

* Capture of changes from directory tables and external tables is not supported. Only standard tables and views are supported.

* Capture of DDL changes is not supported:

  * If the DDL introduces new metadata that did not previously exist, the DDL will be ignored and the task will continue. An example of such a change would be a column that is added to a source table after the task has started.
  * If the DDL is executed on a captured column or table, a table error will occur. An example of such a change would be a captured table that is dropped or renamed after the task has started.

* The Start processing changes from source change position advanced run option is not supported.

* Changes to tables with GEOGRAPHY and GEOMETRY data types will not be captured. The affected table(s) will be suspended.

* Replicate uses the CHANGES clause to capture changes. Therefore any Snowflake’s limitations related to the CHANGES clause will also apply to Replicate.

  For more information, see [CHANGES](https://docs.snowflake.com/en/sql-reference/constructs/changes).

* Homogeneous replication is not supported.

* STRING and BYTES columns without a specified size will be replicated to the target with their maximum size (16 GB for STRING and 8 GB for BYTES).