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Log record buffering
is a technique used in database systems to improve the efficiency and performance of logging mechanisms.
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Buffer management
is a critical component responsible for managing the cache of data pages in memory. Its primary goal is to optimize database performance
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Data Integrity and Reliability
Log record buffering ensures that critical data, such as sensor readings and system events, are captured and stored reliably, even in the face of system failures, interruptions, or network issues.
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Performance Optimization
Log record buffering can also contribute to performance optimization by reducing the overhead associated with frequent disk writes or network transmissions.
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Database buffer
can be implemented either in an area of real main-memory reserved for the database, or in virtual memory
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Concurrency Control
By managing access to buffer frames and coordinating access to shared data, buffer management helps ensure data consistency and integrity across concurrent transactions.
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Buffer management
is essential for ensuring data consistency and durability in the event of system failures.
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Recovery with early lock release
is a technique used in database management systems (DBMS) to improve concurrency and performance by releasing locks held by transactions as early as possible during the recovery process.
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B+Tree indexing
is a method of accessing and maintaining data
10rollback/ undo recovery technique
is based on the principle of backing out or undoing the effects of a transaction that has not been completed successfully due to a system failure or error
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commit/ redo recovery technique
is based on the principle of reapplying the changes made by a transaction that has been completed successfully to the database.
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ARIES recovery algorithm
is a well-known technique used in database systems to ensure atomicity, consistency, isolation, and durability following system crashes or failures.
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Remote Backup Systems
provide high availability by allowing transaction processing to continue even if the primary site is destroyed.
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Detection of failure
Backup site must detect when primary site has failed.
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Transfer of control
To take over control backup site first perform recovery using its copy of the database and all the long records it has received from the primary. Thus, completed transactions are redone and incomplete transactions are rolled back.
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Time to recover
To reduce delay in takeover, backup site periodically processes the redo log records (in effect, performing recovery from previous database state), performs a checkpoint, and can then delete earlier parts of the log.
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One-safe
commit as soon as transaction’s commit log record is written at primary.
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Two-very-safe
commit when transaction’s commit log record is written at primary and backup.
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Two-safe
proceed as in two-very-safe if both primary and backup are active. If only the primary is active, the transaction commits as soon as is commit log record is written at the primary.