Connection Capabilities

GeoCrew

Locking


A user can use locking to gain update control of an object in the data store to the exclusion of other users. There are two general types of locks - transaction locks and persistent locks. Transaction locks are temporary and endure only for the duration of the transaction. Persistent locks applied to objects by a user remain with the object until either that user removes those locks or the locks are removed by another user with the appropriate authority. Following locking types are available:



Transactions


A transaction changes the data store in some way. The way these changes affect the data store is determined by the transaction's properties. For example, the Atomic property specifies that either all changes happen or non happen. In transaction processing the data store treats a series of commands as a single atomic unit of change to that data store. Either all changes generated by the commands are successful or the whole set is canceled. A transaction is a single atomic unit of changes to a data store. The application terminates a transaction with either a commit, which applies the set of changes, or a rollback which cancels the set of changes. Further, the data store may automatically roll back a transaction if it detects a severe error in any of the commands within the transaction. A transaction has the following properties:



Long Transactions


A long transaction (LT) is an administration unit used to group conditional changes to objects. Depending on the situation, such a unit might contain conditional changes to one or to many objects. Long transactions are used to modify as-built data in the database without permanently changing the as-built data. Long transactions can be used to apply revisions or alternates to an object.


A root long transaction is a long transaction that represents permanent data and that has descendants. Any long transaction has a root long transaction as an ancestor in its long transaction dependency graph. A leaf long transaction does not have descendants.


Threading



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