Abdul Hafeez Kalsekar -- Oracle database tuning case studies

  NoSQL, standing for “not only SQL,” refers to databases that store and manage data differently than relational databases. NoSQL databases are designed to handle unstructured data and are known for their flexibility. They can be categorized into four main types: document, key-value, wide-column, and graph databases. Key Features: Unstructured Data: NoSQL is suitable for unstructured or semi-structured data. Scalability: These databases offer horizontal scalability. Schema-less: NoSQL databases do not require a fixed schema. Database transactions imply ACID properties, where “I” stands for isolation and concurrency control.  ( Used to control deadlock )  The (serializable) isolation property ensures that the result of concurrently executed transactions is the same as if they had been executed in some serial order. Many DBMSs provide weaker isolation levels for performance reasons, leaving it up to the application developer to choose the proper one. Moreover, a weaker is...

  Define scaling and its types :  Scaling alters the size of a system. In the scaling process, we either compress or expand the system to meet the expected needs. The scaling operation can be achieved by adding resources to meet the smaller expectation in the current system, by adding a new system to the existing one, or both.  Horizontal scaling is best achieved by distributed NoSQL databases (Cassandra, MongoDB) and modern distributed SQL systems (Google Spanner, CockroachDB) that use sharding to distribute data across multiple servers. Vertical scaling is better suited for traditional Relational Database Management Systems (RDBMS), such as MySQL, PostgreSQL, and Oracle, by adding resources like CPU/RAM to a single server Vertical Scaling: When new resources are added to the existing system to meet the expectation, it is known as vertical scaling.  Consider a rack of servers and resources that comprises the existing system. (as shown in the figure). Now when the e...

  What are the recovery models for a database? There are 3 recovery models available for a database. Full, Bulk-Logged, and Simple are the three recovery models available. Primarily, the recovery model is chosen keeping in view the amount of data loss one can afford. If one expects to have minimal or no data loss, choosing the Full recovery model is a good choice. Depending on the recovery model of a database, the behavior of the database log file changes. I would recommend you read more material on log backups and log file behavior and so on to understand in depth. What are different backup types  Full Backup: BACKUP DATABASE [DBName] TO DISK = 'C:\Path\DB.bak'. Differential Backup: BACKUP DATABASE [DBName] TO DISK = 'C:\Path\DB.bak' WITH DIFFERENTIAL. Transaction Log: BACKUP LOG [DBName] TO DISK = 'C:\Path\DB.trn' Same can be scheduled using Maintenance Plans: Use the Maintenance Plan Wizard to schedule recurring backups with automated cleanup of old files How...