Definition of 'Persistent Data'

What is the definition of 'Persistent Data' as related to the definition of a RDBMS?

thx,

Kat

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.

|||In a simple form it means saved to disk (not only used for data, any file could be persisted-saved).|||

hi kat,

i encounter the term "persistent data" in the .net terminology

which refers to data in the cache of an asp.net application

its in one of the three caching method of .net which are page, fragment and data caching.

you can also persist the data from the dataset to a XML file

oh well, terms are used in different ways and honestly

i dont have any idea about the subject matter.

well, just wanna say hi!

anyway, here are some usefull link

http://en.wikipedia.org/wiki/Persistent_data_structure

http://www.techweb.com/encyclopedia/defineterm.jhtml?term=persistent+data

joey

|||

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