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Dokumentation

ABENSHARED_BUFFER - SHARED BUFFER

Cross-Transaction Application Buffer

The cross-transaction application buffer is an area of memory on an application server that can be accessed by all processes of an R/3 instance.

Application programs can make use of this buffer to

• Store (export) data with the EXPORT ... TO SHARED {BUFFER|MEMORY} dbtab(ar) statement,

• Read (import) data with the IMPORT ... FROM SHARED {BUFFER|MEMORY} dbtab(ar) statement and

• Delete data with the DELETE ... FROM SHARED {BUFFER|MEMORY} dbtab(ar) statement.

As soon as data has been stored in the application buffer, it is visible to all transactions on the application server.

With EXPORT TO SHARED BUFFER, if the memory limit is reached, data not used for some time may be pushed out by new data to be stored. For this reason, an application program should not assume that the stored data can always be reimported. It may have been deleted (for example by transactions running in parallel), replaced by new data or pushed out due to lack of space.

With EXPORT TO SHARED MEMORY, data is not automatically pushed out. Data must be explicitly deleted using DELETE FROM SHARED MEMORY before the maximum limit is reached.

As with EXPORT ... TO DATABASE dbtab(ar), the structures used with the EXPORT, IMPORT and DELETE statements (i.e. specification of the dbtab) must have a standardized structure.

The application buffer keeps the data of the different structures (dbtab) used with EXPORT statements separate.

Please consult Data Area and Modularization Unit Organization documentation as well.