Orange County: Web-based Record Retrieval and Management System

Read more in the Dec. 2000 EOM Magazine article

In 1999, The County of Orange contracted MRF Geosystems Corporation to develop a Web-based record viewing and retrieval system. In undertaking the project, MRF scanned and geo-referenced all 266,000 public records and linked each set of resulting TIF images to a geographic location within the county’s vector GIS land base. In May 2000, the system was made available via an intranet to all applicable County departments.

County employees can now search, query, and retrieve public records (raster images) and vector GIS data that is stored in Intergraph’s MGE/MGDM system using a standard Web browser with the appropriate plug-in. In the browser, users simply draw a polygon on top of a vector land-base display, and the system will then report and provide links to scanned images of all requested land records that fall inside the polygon.

Oracle database and GeoMedia Web Map were used to support the large volume of data management and web GIS capability. Please refer to the following screenshot:

This project demonstrates the following capabilities of MRF:

Ability to administrate an Oracle Database

  • Design and creation of an Oracle Database: Designed and created database new tables and table relationships in Oracle V7.3.3 and V8.0
  • Loading of an Oracle Database: Used SQL Loader and custom utilities to load data into Oracle tables for the “Populate Image Attributes” deliverable
  • Create and Maintain Indexes in an Oracle Database: Created and maintained indexes for the Oracle tables
  • Performance Optimization of an Oracle Database: Created and expanded tablespaces and expanded the rollback segment, to improve database performance
  • Database Recovery of an Oracle Database: Performed database recoveries for the project when the database became corrupted in a batch table creation process. The recovery process consisted of fixing the join relationships, and restoring the database and rolling forward the journal transactions.
  • Client/Server Configuration of an Oracle Database: Developed client/server configurations for the project.

Ability to develop Web-enabled applications

MRF implemented the Web-based Record Viewing and Retrieval System for the Orange County using GeoMedia Web Map. Related tasks include:

  • Web interface design
  • Viewing of Geotiff images together with vector data
  • Use of GeoMedia Web Map objects to create maps and special filtering of the vector data
  • View the landbase data, based on scale setting. Four groups of different vector data at different scales were used for display. For example, Group A scale allows the display of all the detailed vector data such as parcel maps, street names. Group D will display larger scale vector features such as the city boundary and major highways.
  • Using MGE connections to directly view landbase data. No other conversions are needed.

Ability to create MGE features

MRF created non-graphical (i.e. Parcel Map Record) and graphical MGE features (i.e. township plats) for the project through the following steps:

  • Created an Oracle database user
  • Create an MGE Schema, an MGE Project, MGE Tables, and the MGE Features
  • For non-graphic features, entered attributes to the MGE table

For graphical features, MRF used Microstation to digitize the features and entered the attributes into the corresponding table record, then link the MicroStation element to the database table record.