Beaver's functionality

 The errors you're encountering are due to differences in the SQL functions supported by Oracle and SQL Server. The LEFT and ISNULL functions are specific to SQL Server, and Oracle does not recognize them, which is why you're getting the ORA-00904: "LEFT": invalid identifier error.

Solutions:

Use Oracle-Compatible Functions:

For LEFT, use Oracle's SUBSTR function:

SELECT COLA, SUBSTR(COLB, 1, 10) FROM TABLEA;

For ISNULL, use Oracle's NVL function:

SELECT COLA, NVL(COLB, 'default_value') FROM TABLEA;

Transform Data in SQL Server:

If you can migrate the data without transformations, you can use the SQL Server-specific functions like LEFT and ISNULL after the data has been moved.

DBeaver Script Configuration:

If you want to write cross-platform scripts, you can use DBeaver's functionality to define SQL scripts for each database type, ensuring the correct functions are used for each.

If you need to run these functions as part of the migration process, you'll have to use Oracle-compatible syntax until the data is in SQL Server.

Upgrade SQL Server 2008 R2 to SQL Server 2022

 Upgrading from SQL Server 2008 R2 to SQL Server 2022 involves several steps. Here's a general guide to help you through the process:

1. Pre-Upgrade Considerations

• Backup Everything: Before starting, make sure to back up all your databases, including system databases (master, msdb, model) and user databases.
• Check Compatibility: SQL Server 2022 may have different hardware and software requirements than SQL Server 2008 R2. Ensure that your system meets the requirements.
• Review Deprecated Features: SQL Server 2022 might not support some features present in SQL Server 2008 R2. Review the list of deprecated features to plan for alternatives.
• Run SQL Server Upgrade Advisor: Use the SQL Server Data Migration Assistant (DMA) to analyze your SQL Server 2008 R2 databases and identify any compatibility issues.
• Assess and Mitigate Risks: Ensure that any custom applications or scripts dependent on SQL Server 2008 R2 will still function correctly after the upgrade.

2. Upgrade Paths

• In-Place Upgrade: Directly upgrade the existing instance of SQL Server 2008 R2 to SQL Server 2022. This is simpler but can involve more downtime.
• Side-by-Side Upgrade: Install SQL Server 2022 on the same or a different server, then migrate the databases from SQL Server 2008 R2 to SQL Server 2022. This allows for easier rollback if something goes wrong.

3. Perform the Upgrade

• In-Place Upgrade Steps:

  1. Prepare Your Server:
     • Disable or stop any unnecessary services and processes.
     • Ensure that no users are connected to the databases.
  2. Run SQL Server Setup:
     • Insert the SQL Server 2022 installation media.
     • Select "Upgrade" from the SQL Server Installation Center.
     • Follow the prompts, choosing the instance of SQL Server 2008 R2 to upgrade.
  3. Post-Upgrade Tasks:
     • Test the upgraded instance thoroughly.
     • Check that all services are running properly.
     • Review logs for any issues or warnings.

• Side-by-Side Upgrade Steps:

  1. Install SQL Server 2022: On the same server (or a new one), install SQL Server 2022.
  2. Migrate Databases:
     • Use the Backup and Restore method or Detach and Attach to move databases from the old instance to the new one.
     • If using the Copy Database Wizard, be mindful of any potential issues.
  3. Migrate Logins, Jobs, and Other Server Objects: Use the sp_help_revlogin stored procedure to transfer logins, and script out SQL Server Agent jobs and other objects.
  4. Update Connection Strings and Applications: Ensure that all applications are pointing to the new instance of SQL Server.
  5. Post-Migration Validation:
     • Validate that all databases and applications are functioning correctly.
     • Check performance and address any issues.

4. Post-Upgrade Tasks

• Update Statistics: Run UPDATE STATISTICS on your databases to optimize query performance.
• Test Everything: Perform comprehensive testing to ensure that your environment is working as expected.
• Monitor Performance: Monitor the SQL Server performance closely after the upgrade to identify and resolve any issues.
• Documentation: Document the upgrade process and any issues encountered for future reference.

5. Final Steps

• Decommission Old Instance: If the upgrade is successful and everything is working fine, decommission the old SQL Server 2008 R2 instance.
• Continuous Monitoring: Continue monitoring the SQL Server environment to catch any potential issues early.

This process requires careful planning and execution, especially when upgrading across multiple versions. Always ensure you have a tested rollback plan in case something goes wrong.