There are four main types of joins in SQL: In addition to these four main types of joins, there are also a few other types of joins, such as: The type of join that you use will depend on the specific requirements of your query. For example, if you want to find all customers who … Read more
Optimistic and pessimistic locking are two different concurrency control mechanisms used in databases and multi-user systems to handle concurrent access to shared resources, such as database records, files, or data structures. Both mechanisms aim to prevent conflicts and maintain data consistency when multiple users or processes attempt to access and modify the same resource simultaneously. … Read more
Normalization is the process of organizing data in a database in a way that minimizes redundancy and dependency, and thus improves data integrity. There are several levels of normalization, each of which has its own set of rules. To normalize a MySQL database, you can use the following steps: Once you have normalized your database, … Read more
The choice of whether to use a NoSQL or relational database depends on the specific needs of your application. Here are some factors to consider when making your decision: Here are some specific use cases for NoSQL databases: Here is a table that summarizes the key differences between NoSQL and relational databases: Feature NoSQL Relational … Read more
Optimising the performance of a relational database is crucial for ensuring efficient and responsive applications. Here are my top five checks you should focus on to improve the performance of your relational database: Bonus Tip: Caching: Implement caching mechanisms to store frequently accessed data in-memory. Caching can reduce the number of database queries and significantly … Read more
Here is some code to help identify what has been applied and what is missing. Archivelog gap Log Gap Check Get Archive Logs from Backup Stop and Start Apply Services