Learn more about

SaaS Platform Modernization and Database Migration to PostgreSQL on Amazon RDS

Executive Summary Challenge: To modernize its Project and Portfolio Management (PPM) SaaS platform,  OpenText (formerly Micro Focus) made the call to shift its products from on-premises Oracle servers to PostgreSQL on Amazon RDS. They faced various hurdles due to inconsistencies within the database and the legacy architecture of their app. They also requested a reusable custom algorithm for forthcoming migrations. Solution: The ABCloudz team successfully migrated the OpenText database from Oracle to Amazon RDS cloud. The ABCloudz team leveraged DMS […]

Alexander Gora
Custom data migration solution for a complex Oracle to PostgreSQL migration project using AWS DMS

In this post we’d like to share with you our experience in delivering a sophisticated database migration solution on top of AWS DMS for one of our large enterprise customers. The client is a large technology corporation that provides software solutions and services for telecom giants and mid-size companies. They ran numerous Oracle databases where they stored billing and other financial data. In an effort to cut costs for operational infrastructure, the company started the migration of their Oracle systems […]

Alexander Gora
Oracle to MySQL migration with AWS SCT: How to convert BULK COLLECT clause

In this blog post we continue covering AWS SCT conversion issues, adding to the series where we help developers to deal with complex migration issues that can’t be automated with SCT. Today we are going to look into how SCT Build #660 addresses the conversion of statements with BULK COLLECT clause. In Oracle, you can retrieve an entire result set and store it in a PL/SQL collection type variable in a single operation. This can be completed with a SELECT […]

Artem Avetyan
Oracle to MySQL migration with AWS SCT: How to handle unsupported NumToYmInterval function

Here’s one more insight into common code conversion issues while using AWS SCT build number 660. This time, we will tell you how to convert NumToYmInterval from Oracle to MySQL. Oracle has a NumToYmInterval function that converts the provided number value of specified expressions or time units to an interval year to month literal. Usually, interval values appear when it comes to dealing with dates. The challenge MySQL partially supports intervals. However, it doesn’t support storing values of this type […]

Artem Avetyan
Oracle to MySQL migration with AWS SCT: How to convert variables of SYS_REFCURSOR datatype

We continue our series of common issues pertaining to code conversions with AWS SCT. This time, we analyze the peculiarities of converting REF CURSOR types from Oracle to MySQL with the help of AWS SCT build number 660. In Oracle 9i, there is the predefined SYS_REFCURSOR type, which means that defining our own REF CURSOR types is no longer needed. Normally, we define the CURSOR variable of a weak type with Oracle SYS_REFCURSOR datatype. This applies to the cases when […]

Artem Avetyan
An overview of the remote migration from Oracle to SQL Server with SSIS

One of our clients, a large financial software company, wanted to migrate their billing solution from Oracle to SQL Server. They needed to initiate this project because the migration was required by one of their strategic partners. The customer decided to implement SQL Server Integration Services (SSIS) for this migration. Additionally, they needed to do the data transfer from Oracle to SQL Server. Because of the complexity of the project, the client sought software developers that would build an automated […]

Andrey Khudyakov, Roman Muzyka
Conversion of Oracle schemas with hierarchical queries to SQL Server

One of our clients, prominent information technology company, needed to migrate its Oracle database to SQL Server so they called ABCloudz. They knew they wanted to automate the major part of the migration with SQL Server Migration Assistant (SSMA) but there were some challenges associated with this process. First, the company’s source database code contained over 400 hierarchical queries that could not be converted with SSMA. And second, the company’s technical staff was also unable to convert such queries. By […]

Andrey Khudyakov (DB architect), Roman Muzyka (writer)
Schema mapping in migration from Oracle to SQL Server

The migration of Oracle databases to Microsoft SQL Server brings many challenges. One of the most significant is associated with mapping Oracle schema to SQL Server. At the architecture level, the wrong approach will result in significant effort in the future. For example, you may even need to rewrite your app’s entire code from scratch. The problem Oracle database server includes an Oracle database and an Oracle instance. You may learn more about the architecture of the Oracle server here. […]

Andrey Khudyakov, Roman Muzyka
Use caution when mapping Oracle data types for procedures and function parameters in SSMA

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 […]

Andrey Khudyakov (DB architect), Roman Muzyka (writer)
Oracle to SQL Server migration with SSMA: Converting materialized view with float type

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 […]

Andrey Khudyakov
Database migration with SSMA: Handling typical conversion errors

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 […]

Andrey Khudyakov, Roman Muzyka
Oracle to SQL Server migration with SSMA: Converting interval literals

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 […]

Andrey Khudyakov, Roman Muzyka
Oracle to SQL Server migration with SSMA: Converting unsupported table expressions

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 […]

Andrey Khudyakov (DB architect), Roman Muzyka (writer)
Oracle to SQL Server migration with SSMA: Converting foreign keys with different types of columns and referenced columns

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 […]

Andrey Khudyakov (DB architect), Roman Muzyka (writer)
Oracle to SQL Server migration with SSMA: Converting unparsed SQL — Pivot Operator

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 […]

Andrey Khudyakov (DB architect), Roman Muzyka (writer)

Hi there! How can I help you?