mode documentation

Author: Manan007224

docs/source/copydbforeignkey.rst

@@ -12,16 +12,28 @@ Prerequisites
 
 Before migrating tables with foreign key constraints via copydb there are a couple of things to take care of 
 
-- Ghostferry needs to be ran with `SkipForeignKeyConstraintsCheck = true`, which will disable ghostferry to check foreign key 
+- Ghostferry needs to be ran with ``SkipForeignKeyConstraintsCheck = true``, which will disable ghostferry to check foreign key 
   constraints during initialization.
 
-- Source DB should be read_only.
+- Source DB should be ``read_only``.
+
+- Need to disable foreign key constraint checks on target DB by passing the following config to target db
+ 
+ .. code-block:: json
+
+  "Params": {
+    "foreign_key_checks": "0"
+  }
+
+- Even though foreign key constraint checks are disabled on target db, table and db creation must happen in a specific order (eg parent should be created
+  before child table). This creation order can be specified by passing ``TablesToBeCreatedFirst`` in the config, or else the table creation order will be 
+  figured out by copydb. 
 
 Limitations
 -------------
 
 - While migrating tables with foreign key constraints the source db should be read_only as there are some fundamental issues when migrating tables with foreign key constraints at the same time when writes are occurring to the source database. This issue descibes briefly why the source database should be read_only during the migration - https://github.com/Shopify/katesql-migration-backend/issues/194.
 
-- `Interrupt-Resume functionality` can be used as long as source database is read_only also during the interrupt period
+- ``Interrupt-Resume`` functionality can be used as long as source database is read_only also during the interrupt period
 
-- `Inline Verifier` can be used as long as it is ensured that the source database is read_only (even during the interrupt period)
+- ``Inline Verifier`` can be used as long as it is ensured that the source database is read_only (even during the interrupt period)