Write a program to simulate log based protocol using immediate database modification
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property of DBMS states that either all the operations of transactions must be performed or none. The modifications done by an aborted transaction should not be visible to database and the modifications done by committed transaction should be visible.
To achieve our goal of atomicity, user must first output to stable storage information describing the modifications, without modifying the database itself. This information can help us ensure that all modifications performed by committed transactions are reflected in the database. This information can also help us ensure that no modifications made by an aborted transaction persist in the database.
Log and log records –
The log is a sequence of log records, recording all the update activities in the database. In a stable storage, logs for each transaction are maintained. Any operation which is performed on the database is recorded is on the log. Prior to performing any modification to database, an update log record is created to reflect that modification
To achieve our goal of atomicity, user must first output to stable storage information describing the modifications, without modifying the database itself. This information can help us ensure that all modifications performed by committed transactions are reflected in the database. This information can also help us ensure that no modifications made by an aborted transaction persist in the database.
Log and log records –
The log is a sequence of log records, recording all the update activities in the database. In a stable storage, logs for each transaction are maintained. Any operation which is performed on the database is recorded is on the log. Prior to performing any modification to database, an update log record is created to reflect that modification
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