Simple Multiwrite Databases

Administrator User Guide

Multiwrite Databases and Extracts : Simple Multiwrite Databases

Multiwrite databases allow more than one user to write to the same database. Elements in multiwrite databases must be claimed when they are modified so that no other user can change them at the same time. When you create a multiwrite database, you must set its claim mode:

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If the claim mode is explicit, users must explicitly claim any element they wish to change before the modification starts.

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If the claim mode is implicit, an element will automatically be claimed when it is modified.

If a user tries to claim an element that has already been claimed, the second claim will fail. The disadvantage of implicit mode is that users may spend some time defining a change, for example, filling in a form, and then not be able to apply the form if the element has been claimed by someone else.

In a simple multiwrite database, all claimed elements are released when you change modules. Elements can be released at any other time, providing they have not been modified since the last SAVEWORK.

You can only claim primary elements. See the appropriate Reference Manual for each AVEVA E3D™ module for information about primary elements, and what happens in special cases.