Can you swap pervasive SQL for MS SQL (or any other)?

 Yes, it's possible to swap Pervasive SQL (now known as Pervasive PSQL or Actian PSQL) for Microsoft SQL Server (MS SQL) or other database management systems, but the process involves several key steps. Here’s an overview of what that would entail:

Steps for Switching from Pervasive SQL to MS SQL (or another DBMS):

1. Assess Database Schema Differences:

   • Pervasive SQL and MS SQL differ in their schema definitions, data types, indexing mechanisms, and more. You would need to analyze the structure of your current Pervasive SQL database and compare it to the target MS SQL database.
   • For example, Pervasive SQL may use data types like DECIMAL or CHAR with different precision, while MS SQL might have slight differences in how those data types are implemented.

2. Database Schema Conversion:

   • You’ll need to recreate the schema in MS SQL by manually translating the tables, views, indexes, and constraints from Pervasive SQL.
   • Tools like SQL Server Management Studio (SSMS), Azure Data Studio, or third-party tools can help automate some of this process.
   • Depending on the size of the database and complexity of the schema, you might need to write custom SQL scripts to handle any transformations (e.g., handling proprietary Pervasive SQL data types or functions).

3. Data Migration:

   • Export Data from Pervasive SQL: You’ll need to extract the data from Pervasive SQL. This can often be done through ODBC, direct queries, or using tools such as Pervasive Data Integrator.
   • Data Transformation: As the data might not match perfectly (due to different data types, formatting, or constraints), some transformation or cleansing may be required before importing it into MS SQL.
   • Import Data into MS SQL: After transforming the data, you can load it into MS SQL using SQL Server Integration Services (SSIS), BCP (Bulk Copy Program), or simple INSERT INTO statements from external scripts.

4. Modify Queries and Stored Procedures:

   • Stored Procedures and Triggers in Pervasive SQL will need to be rewritten in T-SQL (the SQL dialect used by MS SQL). The logic and syntax may differ between the two systems.
   • This might require a careful review of all existing procedures, functions, and business logic embedded in SQL code.

5. Testing and Validation:

   • Thorough testing is required to ensure that the new MS SQL system is behaving the same way as the original Pervasive SQL system. You’ll need to validate that data integrity is preserved and that performance is optimized.
   • Check for differences in behavior related to transactions, locking, and concurrency between Pervasive SQL and MS SQL Server.

6. Application Code Changes:

   • If your application connects directly to the database, it will need to be modified to work with MS SQL. This might involve:
     • Updating connection strings (e.g., from ODBC to SQL Server's native connection method).
     • Adjusting SQL queries if they were written with Pervasive-specific syntax or features.
     • Refactoring any database access code to use the new database management system's features.

7. Performance Tuning:

   • After migrating, you’ll need to optimize performance in MS SQL Server. This might involve analyzing query execution plans, indexing strategies, and server configuration.
   • MS SQL may have different performance characteristics compared to Pervasive SQL, so you’ll need to monitor the system and adjust as necessary.

8. Backup and Rollback Strategy:

   • Always ensure that you have a backup strategy before starting the migration process, in case anything goes wrong. You might want to set up a rollback plan to restore the Pervasive SQL database if needed.

Tools to Help with the Migration:

• SQL Server Migration Assistant (SSMA): Microsoft offers tools like SSMA to help migrate from other databases (including Pervasive SQL) to SQL Server.
• Pervasive PSQL to SQL Server Conversion Tools: There are third-party tools that can assist in the conversion process by handling the data migration, schema conversion, and even query translation.

Things to Consider:

• Licensing Costs: MS SQL Server may have higher licensing and operational costs compared to Pervasive SQL, especially if you need enterprise-level features.
• Learning Curve: If your team is familiar with Pervasive SQL but not MS SQL, there might be a learning curve to get accustomed to SQL Server’s tools and management interface.
• Compatibility: Some applications designed for Pervasive SQL might rely on features specific to Pervasive and could face compatibility issues when transitioning to MS SQL.

Alternative Database Systems:

If you’re considering other databases, you may want to look at options like:

• MySQL or MariaDB (open-source and widely used)
• PostgreSQL (open-source, feature-rich)
• Oracle Database (enterprise-level, with extensive features)
• SQLite (for lightweight use cases)

Each of these would have its own set of steps for migrating from Pervasive SQL, though the process would be similar to the one described for MS SQL.

Would you like further details on any of these steps or help with a specific part of the process?