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Welcome to the third blog post in the overview series dedicated to our 12-step Migration and Modernization Methodology that was adopted by AWS. In our first and second blog posts, we explored the critical role of defining workloads in migration projects and laid out the process of capturing the current architecture and designing the future state architecture as part of the first step of the methodology — Future State Architecture Design.This provided a solid foundation for understanding the scope and […]

Migrating databases from Oracle to Microsoft SQL Server can be a complex endeavor, especially when it comes to dealing with differences in schema structures, data types, and specific SQL clauses. The SQL Server Migration Assistant (SSMA) is a robust tool designed to automate these migrations and minimize manual effort. However, SSMA might not always produce optimal results, and understanding how to overcome these limitations is crucial for a successful migration. At ABCloudz, we’ve encountered these challenges firsthand. Through our experience, […]

Migrating databases from Oracle to SQL Server can be a daunting task, especially when dealing with date and time data. While tools like the SQL Server Migration Assistant (SSMA) offer automated solutions, relying solely on these tools might not always yield the best performance. In this blog, we share examples of how to optimize conversion of Date and Time Conversion functions, after it was generated by SSMA. Key differences between Oracle and SQL Server Oracle and SQL Server handle date […]

One of the largest educational organizations in the United States had been running their data handling system in the Oracle environment. They wanted to reduce maintenance costs due to the expensive Oracle licensing model, which includes an additional fee for the partitioning feature. The ABCloudz team provided a solution for migrating the customer’s database to SQL Server. Reconstruction of the original partitioning system in SQL Server allowed us to significantly lower SQL Server maintenance costs compared to Oracle. Check out […]

Mapping Oracle data types to SQL Server data types is often a problem during Oracle to Microsoft SQL Server database code conversions. A tried and trusted solution is to use an SQL Server database code conversion. Another reliable solution is to use SQL Server Migration Assistant. These solutions enable you to automate Oracle database conversions to SQL Server. However, there might be some issues you should consider while using SSMA. For example, by default, SSMA applies the maximum available size […]

A materialized view is an important property of Oracle. SQL Server recreates the same behavior as this materialized view in several ways. Unfortunately, SSMA may have issues with converting this object to SQL Server. It flags certain conditions as an error. In this blog post, we will overview the error O2SS0522. It goes about cases in which the Oracle materialized view includes FLOAT columns, subqueries, GROUP BY or WHERE clauses, MINUS, INTERSECT, UNION, etc. By default, SQL Server Migration Assistant (SSMA) converts Oracle […]

ABCloudz tech experts possess outstanding experience in migrating databases. For this purpose, we frequently use SQL Server Migration Assistant (SSMA). SSMA utilization may cause various types of errors, so we have created a blog post series which focused on typical database conversion errors. Each post in this series is dedicated to a separate problem statement and presents our recommendations on how it should be approached and fixed. Related posts Here is the list of blog posts on the most common SSMA […]

Oracle enables you to use specific interval literals for indicating a certain period of time. Unfortunately, there is no direct analog for such literals in SQL Server. As a result, when you apply SQL Server Migration Assistant (SSMA) for converting Oracle code with interval literals, you receive an error O2SS0086. The term ‘interval literals’ refers to a fixed data value, such as the constant value term. Interval literals can be specified in terms of seconds, minutes, hours, days, months, or even years. There are two […]

With Oracle table functions, you can define a set of PL/SQL statements in such a way that, when queried, should behave just as a regular query to the table. The table function enables you to manipulate individual collection elements (user-defined object types) in your SQL database code. However, this may create a database migration challenge because  SQL Server Migration Assistant (SSMA) cannot convert Oracle table functions. Instead, it generates a set of the following errors: O2SS0474: Conversion of the user-defined type […]

In Oracle, you can create a foreign key for a table using columns with various data types. Unfortunately, SQL Server Migration Assistant (SSMA) fails to convert them to SQL Server correctly since it does not support such elements. As a result, when you try to convert the Oracle code including the foreign key with the columns of different data types, you will see the following message: «Error O2SS0231: Foreign keys with different types of columns and referenced columns cannot be converted». Read this blog post to find out how […]

The pivot clause is an integral part of the Oracle database. In particular, the pivot_clause of the SELECT statement allows you to write crosstabulation queries. Here you can rotate rows into columns and aggregate data in the rotation process. As an important data warehousing element, pivot rotates a table-value expression. To be more specific, it turns the unique value from one expression column into multiple output columns. Besides, pivot performs aggregations where they are needed on any of the remaining column values […]

In Oracle, database links are important features that enable you to access objects on another database. SQL Server has a direct alternative to this function. It provides a linked server or an OPENQUERY feature that allows you to emulate the database links’ functionality. Unfortunately, SQL Server Migration Assistant (SSMA) fails to convert these links automatically. When you try converting a database link query that refers to remote objects, you get the following error: “O2SS0563: Conversion of database link … is not […]

Preventing clients from overspending is one of our top priorities. Hence, we pay close attention to the cost of Oracle to SQL server migration in order to provide the most economical solutions while keeping the highest level of quality. Over years, we have served many clients and helped them to keep costs under control. For example, we successfully completed an Oracle to SQL Server migration proof of concept project ordered by a governmental organization from South America. While working on the project, […]

Oracle databases have many specific functions and features. For example, it stores a period of time with specific interval expressions. This may cause issues during the database migration from Oracle to SQL Server. When you use SQL Server Migration Assistant (SSMA) for converting Oracle with interval expressions, you will observe the O2SS0006 error message. This may happen because that SSMA does not support type mapping for such expressions. There are intervals of 2 kinds in the source Oracle code: INTERVAL DAY TO SECOND and INTERVAL YEAR TO […]

Proprietary database features often create significant obstacles for developers. To demonstrate as an example, we will take a look at one of Oracle’s most valuable proprietary features – Oracle Call Interface (OCI). It ensures efficient communication between the database and the application code. Surely, you may use other options for connecting to Oracle. However, once you have committed to OCI, switching to another interface becomes a real headache. Read our new blog post to understand how you can overcome challenges […]