Connecting Oracle to SQL Server: 2 Easy Methods

on Data Analytics, Data Integration, Data Processing, Database Management Systems, Tutorials • January 27th, 2022 • Write for Hevo

Oracle to SQL server | Cover image

Database technology is evolving rapidly and new innovations in this field are becoming quite common. Nowadays, many tools help you connect different databases with each other so that you can use the advantages of both technologies. One such process is connecting Oracle to SQL Server.

SQL Server and Oracle are some of the most widely used data storage tools today. They are both relational databases, which means they organize data in defined relationships for easier access. Perhaps the most significant difference between the two is the language.

While both of these tools use the dialects of SQL, they are different in their own right. For starters, SQL Server uses Transact SQL (T-SQL), an SQL extension. On the other hand, Oracle uses Procedural Language/SQL (PL/SQL). These two languages differ in variable handling, with PL/SQL being more complex and powerful.

Both Oracle and SQL Server are widely used databases in big and small companies. They are widely used relational database tools that share several key similarities as well as differences. It is important to understand the key characteristics of both these databases in order to set up a connection between them.

This article provides a comprehensive guide on connecting Oracle to SQL Server. It also provides a general overview of both Oracle and SQL Server to better understand these technologies individually. Furthermore, you will also come across a  few limitations of this process. Read along to find out how you can connect Oracle to SQL Server for your business.

Table of Contents


There are several factors you should check before connecting Oracle to SQL Server. Ensure every one of the following factors is in check. Otherwise, the connection will not work as intended. 

  • ODBC Driver for Oracle should be installed- This is the fundamental tool we will be using to connect Oracle and SQL Server. The ODBC driver uses Open Database Connectivity Interface from Microsoft to allow applications access to data stored in Database Management Systems. This tutorial assumes that you have this driver installed. If not, you can get installation instructions here
  • You should install SQL Server on the same computer you have ODBC for Oracle. 
  • .NET Framework 4.5 must be installed. 
  • Your data source should be a configured system DSN to enable connection from the ODBC source- System DSN (Data Source Name) is used throughout the system and stores connection details like database name and directory. 
  • All the mentioned tools (Driver, SQL Server, and ODBC for Oracle) must be of the same bitness. 

Once you have confirmed all these factors, you can now begin the connection.

Introduction to Oracle

Oracle to SQL server: Oracle Logo
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Oracle Database, also known as Oracle DBMS or Oracle, is a database management software sold and service by the multinational company Oracle Corporation. It is offered on different installation options, including on-prem, on-cloud, or as hybrid installation.

Furthermore, you can get the software in different editions based on your needs. They include Standard Edition, Standard Edition One, Enterprise Edition, Express Edition, and Personal Edition. One of the most common applications of Oracle is running online transaction processing. 

Key Features of Oracle

Below are some of the features that make Oracle useful for practical applications:

  • Offers SQL and PL/SQL support- Oracle translates SQL statements and maps data types according to the software’s ability. 
  • Provides heterogeneous replication, which allows data to be replicated between oracle and non-oracle databases. 
  • Passthrough SQL- This feature allows you to send statements directly to a non-oracle system without the need for interpretation by Oracle Database. 
  • Data Dictionary Translations- This is a collection of information related to objects useful in the databases and their creators. 

To learn more about Oracle, click this link.

Introduction to SQL Server

Oracle to SQL server: SQL Server Logo
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In simple terms, SQL Server is a database engine developed by Microsoft. The fundamental purpose of the software is to provide a platform where you can create, manage, and manipulate databases. The company offers the platform under two different licenses determined by the client’s organizational or personal needs. The licenses are Client Access Level (CAL) and per-core model.

Key Features of SQL Server

  • It offers support for different tools such as SQL Server Management Studio, Database Tuning Advisor, SQL Server profiler, and BI tools. 
  • Online help and live support. 
  • Database engine with SQL support and other high-level languages, including Java. 
  • The Database engine is helpful for backend programming when building applications that support SQL. 
  • Intelligent Query Processing Enhancements- This is AI technology that improves the query optimizer output making SQL Server more efficient.

To learn more about SQL Server, click this link.

Why Migrate Data From Oracle to SQL Server?

Both, Oracle and SQL Server, are very popular relational database management systems and have wide use cases in enterprise applications database management. But, Oracle comes with a heavy price tag and Oracle exclusive features like Oracle enterprise manager or data guard include a heavy price tag. Whereas, SQL Server is cost-effective, delivers all database features under one license cost.

Moreover, the SQL Server proves that having it is worth it because of its robust and powerful data processing architecture. Hence, making many customers prefer to choose SQL Server over Oracle. And, if you are scrutinizing the sustainability of your existing Oracle databases and want to migrate to SQL Server, then continue to read for more info.

  • Easy Installation: SQL Server is simple to use and can be set up using a wizard — unlike other database servers, it does not require command line settings. It automatically downloads updates and features a user-friendly interface with detailed instructions.
  • Better Performance: For improved efficiency, SQL Server has transparent data compression and encryption techniques. To protect sensitive data, it also offers permission management capabilities with user access control.
  • Extremely Secure: The security layers of the SQL Server database are impenetrable to assault thanks to a variety of security methods and advanced encryption techniques. Other security features give SQL Server its well-deserved reputation as a highly secure relational database management system.
  • Easy to Restore and Recover Data: SQL Server includes advanced features for recovering and restoring data that has been damaged or deleted. It offers extensive recovery features that can let you recover the entire database if necessary. SQL’s primary component, the Database Engine, aids in data storage and user queries, including transactions, files, and indexes. Before a transaction commit, log records are written to the disc. If the operating system, server hardware, or Database Engine instance fails, the instance uses transaction logs to roll back unfinished transactions to the point of failure after it is restarted. SQL Server CDC also uses transaction logs to capture data changes.

Ways to Connect Oracle to SQL Server

Method 1: Manual Process to Connect Oracle to SQL Server

In this method, you will use a Linked Server, a tool available in MsSQL that allows you to write and execute commands on Non-SQL databases. This way you can connect the Oracle data to SQL Server easily.

Method 2: Automated Process Using Hevo to Connect Oracle to SQL Server

Hevo Data, an automated no-code data pipeline provides a hassle-free solution and helps you directly transfer data from Oracle to SQL Server within minutes. Hevo is fully managed and completely automates the process of not only loading data from your desired source but also enriching the data and transforming it into an analysis-ready form without having to write a single line of code.

Hevo’s pre-built integration with Oracle and 100+ data sources across databases, files, analytics engines, etc. gives users the flexibility to bring in data of all different kinds in a way that’s as smooth as possible, without having to write a single line of code. Hevo takes full charge of your data transfer process and lets you focus your engineering bandwidth on key business activities.

Methods to Connect Oracle to SQL Server

There are 2 methods you can use to connect Oracle to SQL Server:

Method 1: Manual Process to Connect Oracle to SQL Server

So far, you should have a rough idea of what both Oracle and SQL Server are. Now, there comes a time when you need access to data stored in Oracle via SQL Server. This is where you need a hands-on approach on how to connect Oracle to SQL Server. The tutorial will give you a step-wise procedure on how to link the two software. By doing this, you stand to gain several advantages such as the ones laid out below: 

  • You get access to data stored in Oracle right from the SQL server without the need for coding. 
  • You can perform different actions on data stored in Oracle from SQL Server, such as distributed queries. 
  • You can address data stored in Oracle the same way you would SQL Server.

This method is a pretty straightforward process that will take a minimum of 20 minutes. It is worth noting that we will be using Linked server, a feature available in SQL Server, to make the connection. Also, check out Oracle to Postgres Migration.

A Linked Server is a tool that allows you to perform standard queries in data stored in NoSQL databases, such as in this case, Oracle. Without further ado, let’s get down to setting up our connection between Oracle and SQL Server. You can do this by following the below steps:

Step 1: Setting Up the Linked Server

Follow the steps below to link your Oracle to SQL Server right from the Object Explorer pane:

  • On the Management Studio, choose your SQL Server Instance
  • Click on the Server Objects from the Object Explorer pane and select Linked Servers, then New Linked Server. 
  • A dialog box prompting you for details regarding your Linked Server will appear. Configure as explained below:
    • Name your Linked Server.
    • Select Other Data Source from Server Type.
    •  Under the provider drop-down list, select Microsoft OLE DB Provider for ODBC Drivers.
    • Input the name of your DSN under Data Source Field

Once you correctly perform the tasks laid out above, a new Linked Server will appear under the Object Explorer pane. 

Step 2: Retrieving Data from Oracle

  • Under Linked Servers, find MSDASQL, which will be under providers, and select it by double-clicking as shown below.
Oracle to SQL server: MSDASQL
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  • A list of provider options will appear as shown below.
Oracle to SQL server: Provider Options
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  • Ensure the Allow Inprocess option is unchecked. Next, create a new Linked Server.
Oracle to SQL server: Creating Linked Server
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  • Once you do this, select ‘Microsoft OLE DB Provider for ODBC Drivers’ and ensure you check the following parameters: 
Oracle to SQL server: New Linked Server
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  • Ensure you name the Linked Server, Product Name, and Data Source. You will then be directed to the security section. Provide details as per your organizational specifications. 
Oracle to SQL server: Security Option
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  • On the next window, select the security specifications based on the login format in your Oracle Database as shown below
Oracle to SQL server: Select Security Providers
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That’s it! Once you click ‘Okay,’ the Linked Server will be created. You can verify by testing the connection as shown below.

Oracle to SQL server: Verify Server
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That’s it! You have successfully connected Oracle to SQL Server using the Manual Method!

One limitation of this method includes:

  • Creating a linked server with the ‘Allow Inprocess’ option enabled. –Always disable this option when creating the server, and in case you forget, just delete and repeat the process. 

To overcome this limitation, and several others, and connect Oracle to SQL Server quickly and efficiently, you can use Hevo’s No-code Data Pipelines. Check out the next method to understand how Hevo can help you connect them within minutes.

Method 2: Automated Process Using Hevo to Connect Oracle to SQL Server

Oracle to SQL server: Hevo Logo
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Hevo Data, a No-code Data Pipeline helps you directly transfer data from Oracle and 100+ other data sources (including 30+free data sources) to Databases tools such as SQL Server, Data Warehouses, or a destination of your choice in a completely hassle-free & automated manner. Hevo allows you to move data from Oracle and Amazon RDS Oracle to the desired data destination. With Hevo, you can choose out of Redo Log, Custom SQL, or Table, and decide the method best suited for your Oracle data transfer.

Hevo is fully managed and completely automates the process of not only loading data from your desired source but also enriching the data and transforming it into an analysis-ready form without having to write a single line of code. It provides a consistent & reliable solution to manage data in real-time and always have analysis-ready data in your desired destination. 

The following steps can be implemented to connect Oracle to SQL Server using Hevo:

  • Configure Source: Connect Hevo Data with Oracle by providing a unique name for your destination along with your database credentials such as username and password. Hevo supports Generic Oracle and Amazon RDS Oracle. To help Hevo connect with your Oracle database, you will also have to provide information such as the host IP, port number, and the name & schema of your database.
Oracle to SQL server: Oracle Settings
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  • Integrate Data: Load data from Oracle to SQL Server by providing your SQL Server database credentials, such as your authorized username and password, along with information about your host IP and port number value. You will also need to provide a name for your database and a unique name for this destination.
Oracle to SQL server: SQL Server Settings
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Check out what makes Hevo amazing:

  • Faster Implementation: A very quick 3-stage process to get your pipeline setup. After that, everything’s automated while you watch data sync to SQL Server or any other destination in real-time. 
  • Real-time Alerts & Notifications: With Hevo, you are always in the know about your data transfer pipelines. Receive real-time multiple-format notifications across your various devices.
  • 100% Complete & Accurate  Data Transfer: The entire ETL spectrum is covered by Hevo. Quality rules and expert engineering also ensure that data is always 100% transmitted so there’s no risk of data corruption or missing data.
  • Scalability Assured: Hevo simply scales to meet your needs today and tomorrow thanks to its world-class infrastructure and platform.
  • A wide array of Data Source Integrations: Hevo has native integrations with 100+ sources across databases, data warehouses, Streaming services, SDKs, etc. Click here for list of 100+ integrations.

Use Hevo’s no-code data pipeline to seamlessly ETL your data from Oracle and other multiple sources to SQL Server in an automated way. Try our 14-day full feature access free trial!

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Oracle to SQL Server Migration Challenges

  • Object Related Mapping: You’ll have to go over the Object-Relational Mapping (ORM) that was used. On Oracle and SQL Server, the same ORM version may support distinct feature sets. It would be prudent to first test the migration process by transferring a small selection of tables and reviewing the results to determine whether ORM changes would necessitate further effort or upgrades.
  • Migrating Indexes: Indexes are database objects that must be migrated since they speed up querying by functioning as pointers to data for quick retrieval. However, the way data is stored in Oracle and SQL Server is highly different, so you’ll need to look at the table layouts and associations, paying special attention to the data’s business requirements and use cases, to come up with an indexing strategy.
  • Conversion Considerations: For the conversion to run smoothly, the conversion scope must be defined. Examine all of the source Oracle schemas, then migrate each schema into its own database or merge them into a single database with several schemas, depending on your needs.
  • Licensing: You should think about the SQL Server license you’ll need before starting the Oracle to SQL Server transfer. You may believe that the SQL Server Standard edition is sufficient for your requirements. The Enterprise Edition, on the other hand, offers several key capabilities that you may require in the future and that can affect the performance, security, and manageability of your data.
  • Database Performance: Before you migrate from Oracle to SQL Server, you should be familiar with the database workload. Examine the frequency of peak loads and performance metrics. After the migration, evaluate the new platform and technology by monitoring CPU, IO, Memory, and Network Traffic demand. Then you can see if the technology resource sizing was done correctly or if you need to do more.


This article gave you a step-by-step guide on connecting Oracle to SQL Server. It also gave you an overview of both Oracle and SQL Server along with their features. Overall, connecting Oracle to SQL Server can be done using either the manual method or by using Hevo. The first method involves manual efforts using significant engineering bandwidth and requires knowledge of SQL. For someone to quickly create a load job from Oracle to SQL Server without going in deep into configurations and other details, an ETL tool like Hevo which can accomplish this in a matter of clicks is a better alternative. 

Hevo Data provides an Automated No-code Data Pipeline that empowers you to overcome the above-mentioned limitations. You can leverage Hevo to seamlessly transfer data from Oracle to SQL Server in real-time without writing a single line of code. Hevo’s Data Pipeline enriches your data and manages the transfer process in a fully automated and secure manner. Hevo caters to 100+ data sources (including 40+ free sources) and can directly transfer data to Data Warehouses, Business Intelligence Tools, or any other destination of your choice in a hassle-free manner. It will make your life easier and make data migration hassle-free.

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