The various oracle processes are listed and explained below Log Writer Background Process (LGWR): This component writes the redo entries from redo log buffers when the user executes the commit statement or the buffer exceeds 1/3rd of the redo log buffers. Database Writer Background Process(DBWR): This component will write all the dirty blocks whenever checkpoints … Read more
Undo/Redo is a database transaction log for handling transaction crash recovery. This algorithm stores all the values and changes made during transactions in a separate memory in case of failure or crash. It utilizes the stored value to restore the loss due to failure. This algorithm is a combination of two approaches UNDO: It stands … Read more
Multiple granularity is a database locking technique that allows various data items of different sizes and set locks on them and also defines the hierarchy of data granularity where small granularities are nested within the larger granularity. There are three types of lock granularity Course granularity: It is used to lock tables, files, databases, and … Read more
Granularity is the size of data items that are allowed to lock. There are three types of lock granularity Course granularity: It is used to lock tables, files, databases, and records. It reduces the transaction number and decreases the throughput to increase the response time of the transaction. But this also causes the concurrency to … Read more
Granularity means the size of data items that are allowed to lock or the level and information type that a lock protects. Multiple granularities is a database locking technique that allows various data items of different sizes and sets locks on them. And defines the hierarchy of data granularity where small granularities are nested within … Read more
Multi-version protocol minimizes the delay for reading operation and maintains different versions of data items. For each writes operation performed, it creates a new version of transaction data so that whenever any transaction performs read operation to read that data then the appropriate created data version is selected by the control manager to make that … Read more
The optimistic control protocol is also called validation-based protocol which copies the transaction data locally and updates the local copy of data instead of actual data in the database. It works in three phases Read phase: All transaction data are read and stored in a temporary variable which is also called the local variable of that … Read more
Timestamp ordering is a unique value given to every transaction whenever it comes into the system to execute. There are two types of timestamp values Read timestamp: It is the value of the last transaction which successfully performed the read operation. Write timestamp: It is the value of the last transaction which successfully performed the … Read more
Strict 2 phase locking This locking technique satisfies the basic 2 phase locking but holds all the exclusive locks until the transaction is committed or aborted during the execution. Some silent features of strict two-phase locking It ensures the transaction should be recoverable and cascadeless. It provides serializability. It provides the guarantee to strict schedules. … Read more
The locking technique uses a lock that guarantees the exclusive use of data of transactions. The lock is used to restrict different transaction which is executing at the same time. 2-phase locking technique It is the same as the Locking technique explained above but it has two phases to act which are: Growing phase: It is … Read more