I had PostgreSQL installation in an EC2 instance. I wanted to migrate to RDS and thus used the DMS service. However, I later came to realize that the data type of the columns have been changed. The changes in the datatype can be seen in the images attached.table in EC2

table in RDS

  • Seems jsonb were converted to varchar(765) and you lost the sequences (and perhaps indexes, have they been migrated?) It's probably a limitation of that DMS service. Have you checked its documentation? – ypercubeᵀᴹ Jul 26 '16 at 10:06
  • @ypercubeᵀᴹ I didn't find any such thing in their documentation. Have you encountered any such thing? Any references would be a great help. – sameergautam Jul 26 '16 at 10:44
  • How did you transfer your data? What versions were both dbs? – JoshRagem Jul 29 '16 at 11:32

The issue related to JSONB columns is a known limitation of DMS. In particular, if you're using DMS to migrate from your EC2 instance to RDS Postgres, it will convert the type to varchar(765) and truncate any JSONB column longer than 756 chars.


We heard during AWS Summit - San Francisco that the DMS team is planning a fix for this issue. For an update, please feel free to comment on the message itself.

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