Migrate Oracle Databases to OCI

Oracle offer six database migration planning advisors. Each of these tools can be used independently or together to help you assess your database migration options, strategy, and complexity. They are grouped into two categories: overall estate assessment and specific technical recommendations. Some tools require little to no preparation and others require complete details of your database estate. If you choose TRY, you can try out these tools.

Here’s brief summary for each of these tools:

Estate Explorer evaluates an entire database estate that you can upload from a spreadsheet or Enterprise Manager. The reporting identify database candidates that require the least effort to migrate to Autonomous Database.

Service Advisor helps you choose which Oracle Database service is best for your requirements.

Methods Advisor provides quick insight to which migration method and supporting technologies are appropriate for specific source and target databases.

Premigration Tool is a detailed technical diagnostic tool that identifies incompatibilities and remediation for upgrades and migrations between databases.

Cloud Migration Advisor is a detailed diagnostics and recommendation tool combining the capabilities of the migration methods advisor and estate explorer plus additional factors to make more precise recommendations.

Enterprise Manager Migration Workbench is an embedded feature of Enterprise Manager. This tool leverages known metadata around your database estate and makes planning recommendations.

Two of these tools, Estate Explorer and Cloud Migration advisor are not yet self-service, but with the help of your Oracle sales person, you can access them. Enterprise Manager is a licensed product, but you can explore the product on a trial basis from within the OCI Marketplace.

You can learn more about these tools and access informative links on the TECHNOLOGIES tab.

In this "Prepare" diagram, there are two layers of preparation steps. The first layer above represents the Cloud Premigration Advisor Tool (CPAT). These are the steps to evaluate and prepare your source databases to be compatible with the target. The steps of CPAT are to identify exceptions, present the findings, take remediation actions or not, then rerun the advisor until all issues are resolved. CPAT is embedded into the automated migration solutions and part of the logical migration method workflows.

The second layer is to perform a test migration. These steps include provisioning cloud resources, run or execute the migration, validate the movement and performance, then reset the environment until you are ready to do execute the migration. PREPARATION means practice running the migration and developing procedures for failure, reset, and recovery.

In this EXECUTE diagram, all Oracle technologies are identified in each of the migration steps.

In the prepare phase, there are two strategies – use automated solutions or do it yourself with any of the component tools, services, utilities, and products. Regardless of your choice, the next step is to use the Cloud Premigration Advisor Tool to test the source database metadata and data against the compatibility requirements of the target database.

In the execute phase, there are two business continuity factors to choose from – online or offline. If you choose offline migrations, they can either by physical or logical. Physical means that you use the Oracle Recovery Manager backup-restore function. Logical means you use oracle Data Pump to do a data extract and import. If you choose online migrations, you will either use GoldenGate or Data Guard for the ongoing synchronization as new and changed data is introduced during the migration.

In the validate phase, all migration methods will validate that data moved. In addition to that, the Enterprise Manager solution also includes SQL Performance Analyzer in the workflow which will compare the performance of key SQL statements on both the original and migrated database.

Oracle GoldenGate Veridata validates that source and target databases are in sync. This is especially important during long migrations or in a complicated database implementation where multiple databases must stay in sync incrementally even during the migration.

This OVERVIEW diagram describes the primary elements in selecting a migration method and its business and technical planning factors. The result of this planning exercise leads you to either automated or do it yourself migration execution. The migration methods advisor and the cloud migration advisor will make recommendations base on these two groups of planning factors.

The business planning factors include tolerated downtime, impact on application performance, impact on application architecture, and the simplicity or complexity of the migration process which will impact business risk.

The technology planning factors impact the degree and performance of automation processes. Database considerations include source and target version and platform, whether advanced database features were used, size of database, and extent and experience of migration skills.

Oracle provides two categories of migration methods: fully or partially automated solutions or a do it yourself strategy allowing DBAs to orchestrate their own custom migration workflows using use of any or all of Oracle tools and technologies.

Lastly, the migration process is much simpler if you delegate the actual migration work to Oracle or third parties. Oracle or its partners are always eager to help you.

This diagram describes how the zero downtime migration family of solutions work.

First, the picture illustrates which specific database sources and OCI targets are supported. Source databases include on premises Oracle databases and Oracle Exadata and OCI databases, Oracle Exadata Cloud Service, and Exadata Cloud at Customer. In addition, Oracle Database on AWS are included.

Target OCI databases include Autonomous Database, ADB-Exadata Cloud at Customer, Exadata Cloud at Customer, Exadata Cloud Service, and the Oracle Base Database service.

Zero Downtime migration has five primary phases. Readiness, Initial load, Ongoing capture and apply, Final switchover, and then completion.

In the prepare or readiness phase, customers manually or automatically use the Cloud Premigration Advisor Tool to test source database against the planned target requirements.

From there, user choice decides one of the two options for database migration Physical migrations use Recovery Manager for initial load and data guard for ongoing synchronization. Logical migrations use Data Pump for initial load and GoldenGate for ongoing synchronization.

At the conclusion of both migration styles, a technical switchover occurs and the target database becomes the active database.

The final step evaluates migration performance and then cleans up the technical environments.

Enterprise Manager Database Migration Workbench helps you migrate from 11g to 21c container or non-container databases to many on-premises and cloud versions and platforms. On-premises Oracle Database sources include Standard and Enterprise Edition and Exadata Database Machine. OCI Database sources include Base Data Service, Exadata Cloud Service, and Exadata Cloud@Customer. Target OCI Databases include Base Database Service, Exadata Cloud Service, Autonomous Database, and Exadata Cloud@Customer.

Migration Workbench can be used to choose source and target databases and create migration flows for either a full or partial database migration either using physical or logical migration methods. The physical method makes use of Oracle Data Pump. The logical method makes use of Oracle Recovery Manager Transportable Tablespaces.

In the database validation phase, the Premigration Advisor analyzes the source for target database compatibility. It looks for potentially problematic content and makes recommendations. Once all errors are addressed, the physical or logical migration method begins.

If Data Pump is used, metadata and data is exported from the source to intermediate storage in OCI Object Storage in an encrypted format. From OCI Object Storage, metadata and data are moved to the target database.

If Transportable Tablespace is used, metadata and data are exported from the source to the target storage using Recovery Manager backup capabilities. Then, the Recovery Manager restores the metadata and data to the target database.

Several migration analytics tools are available. Migration analysis reports on step-by-step migration processes with a pre- and post-migration validation summary and details on failures.

SQL Performance Analyzer compares SQL performance before and after the migration between the source and target databases. It reports on the positive or negative performance impact along with root cause and tuning recommendations. SQL Performance Analyzer is part of Oracle Real Application Testing suite database option and is embedded in the Migration Workbench.