Stabilizing Query Based Replication

[saisrirampur]

1. When source table in PG is empty - getting the below error:

   "message": "failed to get partitions from source: unsupported type: <nil>",
   "source": "GoSDK",
   "stackTrace": "",
   "encodedAttributes": null,
   "cause": {
   "message": "unsupported type: <nil>",
   "source": "GoSDK",
   "stackTrace": "",
   "encodedAttributes": null,
   "cause": null,
   "applicationFailureInfo": {
     "type": "",
     "nonRetryable": false,
     "details": null
   }
   },
   "applicationFailureInfo": {
   "type": "wrapError",
   "nonRetryable": false,
   "details": null
   }
   }

2. In query based replication, we should allow 2 MIRRORs with same name. But as we removed the unique constraint for name (because of multi-table CDC), we are allowing. We might need to rethink the data-model for flows table. One approach is to separate metadata tables for CDC and Query Based Replication.

[iskakaushik]

closing this after successful scale testing.