Database Management
Reference Manual
Introduction to Database Concepts
:
Extracts
: Extract Operations
Extract Operations
The following operations are allowed:
Drop
This is the process of losing modifications done locally on an extract combined with the transfer of write extract back to the parent extract.
Partial Drop
This is the process of losing modifications done locally on a subset of elements, combined with the transfer of write extract back to the parent extract.
Issue
The local changes are copied to the parent extract, and the elements are released.
Flush
This term is used for issuing without doing a release.
Partial Issue
The Issuing of a subset of the modifications made in the current extract to the parent extract.
Refresh
The mechanism by which an extract is updated with changes made in the parent DB.
The refresh functionality is needed since users work on a constant view of the parent extract DB. Thus they will not see other users' issues until they do a REFRESH. It is akin to the GETWORK functionality in a single multiwrite DB.
All flushing, issuing, releasing and dropping operations work on one level of extract only. A Refresh can be done all the way up the tree using just one command.
If an extract operation fails, then the entire operation is aborted.
1974 to current year.
AVEVA Solutions Limited and its subsidiaries. All rights reserved.
