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I am planning to migrate Oracle 11g to MS SQL Server 2016,

hence I performed Pre-Migration assessment through SSMA.

I received final conversion report on SSMA, But with Numerous Number of Errors.the report states that it will require 1263.6hours for manual conversion from Oracle to SQL

Please help me, how shall I resolve these errors with minimum manual conversion time.

Attached is the screenshot for the same.

Appreciate your Help

Thanks,

Amit

enter image description here

Mohsen Alyafei
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Amit Singh
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  • Just looking at the list of errors in the screenshot it appears that your exsting DB relies heavily on PL/SQL objects and user-specified types. Some are even "wrapped" to obfuscate their functionality. I'd estimate most of that code will have to be rewritten, and you will have to find generic or SQL Server-specific alternatives to a lot of the Oracle-specific things your application relies on now. If you were thinking this would be a quick or easy migration, I think you are going to be disappointed. What is the reasoning behind moving to SQL Server at this time? – pmdba Jun 29 '20 at 14:14

2 Answers2

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You must understand one important concept. Migrating from SQL Server to Oracle or vice versa would be as easier as the level of complexity in your source database. In your case, you are using SSMA to make an assessment for your Oracle source database.

Try to read --> rules on SSMA to migrate from Oracle to get more details about the rules applied for each possible transformation.

There is not a concrete answer to your question, you have a lot of different problems in the screenshot you have provided. Most important, even though SSMA will make automatic conversions ( for example Schemas ), you need to evaluate the impact in your application. I saw also problems in PL/SQL objects, that you somehow will need to convert to Transact SQL. Bottom line: you have a lot of manual work to do.

SSMA is making already a case in your situation providing some information that some of the source elements cannot be converted automatically, therefore a manual intervention is needed.

Roberto Hernandez
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As you are discovering, migrating from one DB server to another is not just a simple matter of relocating the data, especially when (as it appears) your application leans heavily on Oracle-specific technology. By all appearances - as noted repeatedly in this thread - you will have a lot of manual reconciliation and rewriting of application code to do. There is a hidden cost here: the time and effort required to do this work doesn't come for free. It will cost your company real $$$ to make this happen. You should be prepared to answer the following questions:

  • Is cost of the amount of time and effort to rewrite the application and complete the transformation going to be less than any cost savings realized by switching from Oracle to SQL Server?
  • Understanding that it may cost more in the short term to rewrite the application than continuing with the status quo, how long will it take to realize any cost savings at all?
  • On a technical level, given the number of Oracle technologies in play (custom types, stored procedures, etc.), can SQL Server even replicate the functionality required by the application that is currently provided by Oracle?
  • What is the driving force behind this migration, and does it really make sense if this level of effort is required?
  • If data migration is still required, is it easier to rebuild the application from scratch and just move the data than it would be to port the entire existing application?
pmdba
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