Migrating a database from on-premises to Azure PaaS has multiple challenges:

Compatibility Issues

• Data Types, Functions, Stored Procedures and Triggers: Differences in data types and SQL functions. Need for rewriting or adjustments.

Performance Tuning

• Resource Allocation: Different resource management on Azure.
• Indexing and Query Optimization: Existing strategies might need re-evaluation.

Data Transfer

• Data Volume: Large data volumes can be time-consuming to transfer.
• Downtime: Minimizing downtime during migration.
• Network Bandwidth: Limited bandwidth can slow transfers.

Security and Compliance

• Data Encryption: Ensuring encrypted data in transit and at rest.
• Access Control: Reconfiguring user roles and access controls.
• Compliance Requirements: Meeting regulatory standards.

Application Dependencies

• Tightly Coupled Applications: Significant changes may be needed.
• Connection Strings: Updating and verifying connectivity.
• Third-Party Integrations: Ensuring compatibility.

Operational Challenges

• Backup and Recovery: Implementing backup and recovery strategies.
• Monitoring and Alerting: Setting up database health monitoring.
• Disaster Recovery: Establishing Azure-specific recovery plans.

Cost Management

• Cost Estimation: Accurately estimating Azure costs.
• Cost Optimization: Identifying cost-saving opportunities.

Testing and Validation

• Functional Testing: Ensuring database functionalities.
• Performance Testing: Meeting performance standards.
• User Acceptance Testing (UAT): Validating with end-users.