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Track: Database Management and SDE
Bruce Tepley
Thomas Bros. Maps
17731 Cowan
Irvine, CA 92714
Telephone: 714-757-5574
Fax: 714-851-2463
E-mail: stepley@thomas.com
Bruce Thomas
Managing Selected Sets of Library Layer Features in ARCPLOT
Defining Issue: Spatial database managers often need to filter and selectively recombine selected subsets of features from large geospatial data sets. ARCPLOT writeselect files are very useful for such purposes; however, they are not usable with ArcInfo LIBRARIAN and ArcStorm layers. GIS Solution: The ArcInfo solution presented is based upon two features of ARCPLOT: 1. Readselect/Writeselect can be performed dependably on INFO key files. 2. Key file selects can be used to transfer the results of combining such selections on the key file to the library layer. Methodology: A layer item is designated for feature identification, the key item. Other layer items are used for selection criteria. A separate "reference" INFO table of these items for identification and selection is created by INFOFILE from all features in the library layer. Indexed key file selection may be used to transfer equivalent record selection sets back and forth between the layer and the reference set. Whenever a set is used for
efficient Boolean combinations (AND, OR, XOR), a writeselect of the reference set is saved. The readselect options are later used for convenience in logical (Boolean) filtering. The resulting records in the reference set will then contain the appropriate key file values in the key item, which are then used to select the same set of features in the layer. Software: Implementation examples are in AML.
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