Here's how you can tackle complex technical issues as a database developer.

- Collect any error messages or codes generated. They often contain clues about the nature of the problem. - Check application and database logs for detailed error information and context. - Identify and document the specific symptoms of the problem. - Determine the scope of the problem—whether it affects a single user, a group, or the entire system. - Determine how often the issue occurs and if it follows a specific pattern or trigger. - Keep detailed notes on what you have observed, tested, and ruled out

- Look at the primary logs generated by the database management system (DBMS) - Check the logs from applications that interact with the database - Filter logs by error level or severity (e.g., ERROR, WARNING, INFO) to focus on critical issues. - Look up any error codes or messages in the database documentation to understand their meaning and possible causes. - Review logs for slow-running queries or operations. - Check for issues related to locking and blocking, which can impact database performance and cause errors. - Check logs for connection pooling issues, which might indicate problems with the maximum number of connections or resource leaks. -

- Clearly outline what you want to achieve with the changes and how you will measure success. - Before making any changes, create a backup of your database to ensure you can restore it to its previous state if needed. - Document the current state of the system, including configurations and schemas, for easy restoration if required. - Run tests on existing features and queries to ensure that they still work correctly with the new changes. - Use validation scripts to check that constraints, indexes, and relationships are still enforced correctly. - Document the outcomes of all tests, including any issues encountered and how they were resolved.

Leider kann man nicht immer eine ?nderung auf einer Nicht-Produktivumgebung testen. Das kann z.B. vorkommen, wenn es um Queries geht und die Tabellen-Statistiken nur auf dem Prod-System aktuell sind und sich der Execution-Plan auf keinem Test-System nachstellen l?sst. Für solche Situationen k?nnte zwar theoretisch ein Statistik-Export/Import funktionieren, wird aber bzgl. Kosten/Nutzen-Verh?ltnis und dem damit verbundenen Aufwand kaum Verh?ltnism??ig sein.

- Document the database schema, including tables, columns, data types, primary keys, foreign keys, and constraints. - Diagram relationships between tables, including one-to-one, one-to-many, and many-to-many relationships. - Include diagrams (ER diagrams, flowcharts) to visually represent database structures and processes. - Document backup procedures, recovery plans, and any disaster recovery strategies. - Document routine maintenance tasks, such as updating statistics, performing integrity checks, and cleaning up logs. - Include documentation as part of the onboarding process for new team members to familiarize them with the database.