AWS DMS - incremental migration from Oracle to Redshift

1
votes

I am new to AWS DMS service. Plans are to migrate on-prem Oracle to Redshift. Before going into production environment, currently trying out a test Oracle RDS in AWS which is a small subset of actual database as source. So far have been successful in the bulk load and incremental migration from RDS to Redshift.

When it comes to on-prem oracle , particularly for the incremental load

1) As per document : http://docs.aws.amazon.com/dms/latest/sbs/CHAP_On-PremOracle2Aurora.Steps.ConfigureOracle.html, the on-prem needs to be enabled with supplemental logging. Plans are to use the following two commands.

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;

The production database has multiple logging locations. Is there any other log settings other than the above two that I should be looking into for DMS to pick up multiple log locations?

2) In the same link given, point 4 says 'Create or configure a database account to be used by AWS DMS.'

Where should I create this user? on-prem oracle or AWS? How do I configure DMS to use this user?

1
oracleamazon-redshiftaws-dms
on dms you should set up and test an "endpoint". to do that you do need to set up a replication instance first as the test is run on that. The endpoint should be set up with the right oracle host / credentials. you need to create and test 2 endpoints - one for source (oracle) and one for target(redshift) - Jon Scott
Thank you for the input Jon. The end points have been successfully created for RDS as source. My question for multiple log location permission and user creation is for the on-prem oracle. Will there be more log permissions for on-prem and how to create/configure user for DMS to access on-prem oracle. - pChidambaram
My suggestion - try it out. (I know its easy for me to say - you may have internal blockers to that approach) - Jon Scott

1 Answers

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You need to read this documentation:

https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.Oracle.html

For your second question; You need to create a user in the Oracle source database, the section 'Working with a Self-Managed Oracle Database as a Source for AWS DMS' tells you all of the grants you need to give.

For your first question, if you look at the SQL Server documentation;

https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.SQLServer.html

It specifies the limitation of; 'SQL Server backup to multiple disks isn't supported. If the backup is defined to write the database backup to multiple files over different disks, AWS DMS can't read the data and the AWS DMS task fails.'

I can't see a similar stipulation in the oracle documentation, first link, I would hazard a guess that DMS is able, in the case of oracle, to determine and cope with multiple logging locations from a configuration value inside the database.