Knowledge Base

KB10881 - Use of the Editor for multi-user GIS solutions.

Use of the TatukGIS Editor (or free Viewer) for a multiple user solution is possible when the data storage is in SQL map layers on a database server. Supported database engines and compatible SQL layer formats are presented in Knowledge Base item KB10639.

Multi-user viewing, querying, report generation, etc. from a common database is easy. The tricky part of a multi-user environment is creating and editing data. What if two or more users edit the same record (vector shape) in a map layer? Should rules be applied to prevent simultaneous editing of the same record or to determine user priority? Should there be a procedure to check out and “lock” a record during editing? Should there be a review/approval process before edited data is updated to the database?

No single set of rules could satisfy all situations and customer requirements. Therefore, the Editor's default configuration reflects a lowest common denominator approach, which is the record in the multi-user database reflects the most recent save operation performed by an authorized user. If, for example, two authorized users unknowingly edit the same record at the same time, with one user saving editing changes one minute before the 2nd user saves his changes, the record in the database will reflect the editing changes performed by the first user only for the one minute period until those changes are overwritten by the save operation performed by the 2nd user.

Just to be clear, a conflict is possible only when two or more users simultaneously access and edit the same database record, i.e. the same geometric shape. There is no conflict when multiple users simultaneously edit records in different map layers or different records in the same layer.

For situations involving a limited number of users who can coordinate to avoid simultaneously editing the same records, the Editor's default method can be just enough. For customer situations requiring more complicated record locking rules based on assumptions about various multi-user scenarios, the Editor’s scripting tools can be used to implement the exact multi-user rules and procedures the customer may require - keeping in mind that implementation must be to the database server side as well as to the Editor on the desktop.
Created: June 27, 2012, Modified: November 03, 2015
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