Clarify that MOLT Fetch does not migrate sequences

src/current/_includes/molt/migration-schema-design-practices.md

@@ -32,6 +32,10 @@ Convert the source schema into a CockroachDB-compatible schema. CockroachDB supp
 
 - Every table **must** have an explicit primary key. For more information, refer to [Primary key best practices]({% link {{ site.current_cloud_version }}/schema-design-table.md %}#primary-key-best-practices).
 
+{{site.data.alerts.callout_danger}}
+Avoid using sequential keys. To learn more about the performance issues that can result from their use, please read [our advice on indexing with sequential keys]({% link {{site.current_cloud_version}}/sql-faqs.md %}#how-do-i-generate-unique-slowly-increasing-sequential-numbers-in-cockroachdb). If a sequential key is necessary in your CockroachDB table, you will need to create it manually, after using [MOLT Fetch]({% link molt/molt-fetch.md %}).
+{{site.data.alerts.end}}
+
 - Review [Transformations]({% link molt/molt-fetch.md %}#transformations) to understand how computed columns and partitioned tables can be mapped to the target, and how target tables can be renamed.
 
 - By default on CockroachDB, `INT` is an alias for `INT8`, which creates 64-bit signed integers. PostgreSQL and MySQL default to 32-bit integers. Depending on your source database or application requirements, you may need to change the integer size to `4`. For more information, refer to [Considerations for 64-bit signed integers]({% link {{ site.current_cloud_version }}/int.md %}#considerations-for-64-bit-signed-integers).

src/current/molt/molt-fetch.md

@@ -125,6 +125,8 @@ To verify that your connections and configuration work properly, run MOLT Fetch
 
 - {% include molt/molt-drop-constraints-indexes.md %}
 
+- MOLT Fetch does not support migrating sequences. If your source database contains sequences, please read [our advice on indexing with sequential keys]({% link {{site.current_cloud_version}}/sql-faqs.md %}#how-do-i-generate-unique-slowly-increasing-sequential-numbers-in-cockroachdb). If a sequential key is necessary in your CockroachDB table, you will need to create it manually, after using MOLT Fetch.
+
 ## Security recommendations
 
 Cockroach Labs **strongly** recommends the following: