Database migration from Oracle to MySQL can offer several advantages, including lower ownership costs, free database engine, tight web integration, and a vast community of MySQL professionals. However, for those setting up a large-scale corporate database, it may be reasonable to stick with Oracle as it provides an ultimate range of features and tools specifically designed for this purpose. In this article, we will outline the key differences between Oracle and MySQL to help you make an informed decision.
The first question to ask before planning a database migration is really necessary to switch corporate data warehouse to new DBMS. For example, one of the key differences between Oracle and MySQL is the licensing model. While Oracle requires a paid license for commercial use, MySQL is open source and free to use for most applications. This can result in significant cost savings for organizations that are looking for a scalable database solution without the high cost of ownership.
Another significant difference is the performance and scalability of the two systems. Oracle is a more powerful and sophisticated database management system that can handle large-scale databases with high transaction volumes. In contrast, MySQL is ideal for small to medium-sized databases and may not be able to handle large-scale enterprise applications without performance issues. However, MySQL has a scalable architecture that allows it to handle high traffic volumes through sharding, clustering, and other techniques.
If we continue to compare the two database management systems, it is important to note that Oracle has a more extensive set of features and tools, such as built-in analytics, advanced security options, and support for complex data types. MySQL, on the other hand, is designed to be simple and easy to use, with a focus on web integration and ease of administration.
To convert an Oracle database to MySQL, several steps need to be followed. Firstly, Oracle table definitions are exported as “CREATE TABLE” statements, which are then transformed into MySQL format and loaded into the target server. Secondly, Oracle data is exported into CSV files, which are then modified to match the target format and loaded into MySQL. The final step of migration itself is to export Oracle views, triggers, stored procedures and functions into SQL statements and source code, which are then converted into MySQL syntax and loaded into the target database. Of course, after database migration is done, it is necessary to run comprehensive performance and functional testing to ensure the target system works properly.
Whether these steps are executed manually or using commercial tools, the individual in charge must understand all possible bottlenecks and techniques for validating the results. Oracle SQL statements can be validated using SQLPlus or any other client application. MySQL has a similar command-line client tool, which can be used to connect to the database and execute queries. However, the syntax and commands for MySQL client are different from SQLPlus, so users must familiarize themselves with the MySQL client to perform the required tasks efficiently.
To connect to the database via SQLPlus, use the following command line:
sqlplus username/password@database
To extract the definition of all tables in an Oracle database, use the following query:
SQL> select table_name from user_tables;
To extract the definition of a specific Oracle table, use the following commands:
SQL> set long 1000
SQL> set pagesize 0
SQL> select DBMS_METADATA.GET_DDL(‘TABLE’,'<TABLE NAME>'[,’SCHEMA’]) from DUAL
To prepare the script for loading into MySQL, certain modifications are necessary. For example, Oracle-specific keywords at the end of CREATE TABLE statements should be removed, Oracle identifier quote characters must be replaced with their MySQL equivalents, and all data types need to be converted to their MySQL counterparts.
To migrate Oracle data into MySQL, CSV files serve as an intermediate storage. To do this redirect query output using Oracle command SPOOL and specify CSV separator via ‘SET COLSEP’ statement. Do not forget to call SPOOL OFF after export into CSV files is completed. The data from those CSV files can be imported MySQL using LOAD DATA statement.
If the steps outlined above seem too complex to perform manually, there are software tools available that can automate and simplify the Oracle to MySQL database migration process with just a few clicks. One such tool is the Oracle to MySQL converter developed by Intelligent Converters software company.
The product provides the following basic capabilities suitable for database migration tasks:
- Support for all modern versions of Oracle and MySQL databases with popular forks and DBaaS (cloud) variations
- Conversion of all database objects, including tables, indexes, constraints and views
- Intelligent conversion of Oracle data types to the most appropriate MySQL types
- Option to filter, merge or preprocess in a different data using SQL queries
- Ability to customize the resulting MySQL table structure (modify name, type and other attributes of every single column as well as exclude it from migration)
- Option to merge and synchronize Oracle data into an existing MySQL database
- Option to export Oracle data into MySQL script files
Visit official site of Intelligent Converters to learn more about their Oracle to MySQL database migration tool.
