The speed of multi-user access to geo-spatial databases has been increased in the GIS Server


In KB "Panorama" the GIS Server version 7.3 is developed. The new version increases the speed of access to large arrays of information in spatial databases. This is achieved by the flexible configuration of data caching and the possibility of cache distribution over disk arrays.

The program provides caching of information from a spatial database in the form of a cartographic representation already in established conventional symbols. This allows you to maximize the speed of multi-user access to this data. In the new version, for each GIS Server connection with the geo-spatial database, a separate directory can be assigned in the disk space for cache placing. This approach allows the server administrator to flexibly distribute the load to the disk subsystem.

The GIS Server allows not to reread from the database the previously received information and stored in the cache, even if this information has not been accessed for a while by any server client, or even if the GIS Server has been restarted. If data logging is available in the database, the GIS Server updates the data in the cache only in the part of the data that has changed since the previous access to the spatial data base. Logging of operations is carried out using an additional table in the database - "Log of data changes". The period of poll by GIS Server of the table of changes log is installed by the manager in program settings.

If the logging of operations is not performed in the spatial database, then the GIS Server must update the entire cache. To minimize the time and resource costs required for this operation, the new version introduces the notion of "time of data relevance". Now the cartographic representation generated by the original data set (geospatial database table or SQL query) is not recreated until the established interval of relevance of the received data has expired, even if during this period the operating system or the GIS Server was restarted. After the time of data relevance expires, the cartographical representation will be automatically re-configured if there are active connections to this data set on the GIS Server. If no one is connected to the dataset and the data timeliness has expired, the cartographic view will be re-formed at the first access of the user to this set. The relevance time for the data set of the spatial database is determined by the administrator of the Server GIS based on what spatial information is contained in this set, how much and how often it is updated for the server's clients.

GIS Server provides remote access to vector maps, remote sensing data, matrices, documents and spatial databases. There is supported a multilevel connection of servers among themselves for the distributed storage and processing of spatial data with automatic replication, backup and data protection. The program gives users the opportunity to make changes to geo-spatial data bases through the graphical interface of GIS "Panorama" by means of editing digital terrain maps. In this case, the GIS Server monitors the changes in these databases, performed by any external applications.

The new version of the program is available for download on the Download page.

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