Hello, Data is said to be persistent in RDBMS when the transaction that has written it is commited. One of cornerstones of RDBMS is the ACID contract between the system and the components that issue transactions. ACID stands for Atomicity, Consistency, Isolation, Durability. The Durability property sais that once a transaction has been commited, its modifications are guaranteed to survive any failure of system, once the permanent storage is not damaged. Another term for Duarbility is Persistence(they just use Durability because ACID is the cutest abbreviature one can think of :) ) So, basically, persistent data is the data that has been issued by a transaction which has already been commited. It is guaranteed to survive any system failures.
Persistent Data is data that stays around after the application has terminated. In the case of an RDBMS, it would refer to data which had been committed to tables. It would not refer to items stored in temporary tables or units of work that the server accumulated while processing a query -- work tables. It would also not refer to variables defined and used during processing.
Definition of 'Persistent Data'
CostasZ
Hello,
Data is said to be persistent in RDBMS when the transaction that has written it is commited. One of cornerstones of RDBMS is the ACID contract between the system and the components that issue transactions. ACID stands for
Atomicity, Consistency, Isolation, Durability. The Durability property sais that once a transaction has been commited, its modifications are guaranteed to survive any failure of system, once the permanent storage is not damaged. Another term for Duarbility is Persistence(they just use Durability because ACID is the cutest abbreviature one can think of :) )
So, basically, persistent data is the data that has been issued by a transaction which has already been commited. It is guaranteed to survive any system failures.
Regards,
Andranik
Jan Kučera
hi kat,
joey
Patrick_Kirk
Vitalijus
Persistent Data is data that stays around after the application has terminated. In the case of an RDBMS, it would refer to data which had been committed to tables. It would not refer to items stored in temporary tables or units of work that the server accumulated while processing a query -- work tables. It would also not refer to variables defined and used during processing.