GIS - Geographic Information System Geodatabase Design and Management Questions and Answers

Question 1

A GIS administrator is designing a geodatabase for a utilities company to manage water distribution assets. To ensure data integrity, the design specifies that for any 'Water_Mains' feature, the 'Material' field (e.g., 'Ductile Iron', 'PVC') must dictate the valid range of values for the 'Diameter_Inches' field. For instance, PVC pipes are only available in diameters from 4 to 12 inches, while Ductile Iron is available from 6 to 36 inches. Which geodatabase mechanism is specifically designed to enforce this type of conditional attribute validation?

Accepted Answer

Contingent values

Answer

Contingent values are the correct mechanism because they are designed to constrain the valid values for one field based on the value of another. In this scenario, the valid values for 'Diameter_Inches' are contingent upon the value selected in the 'Material' field. While subtypes can have different domains assigned to them, contingent values provide a more direct and scalable solution for creating dependencies between fields without necessarily categorizing the entire feature class. Coded value domains only restrict a field to a list of values, and relationship classes manage associations between objects, not conditional validation within a single feature's attributes.

Question 2

An enterprise geodatabase is experiencing performance degradation during periods of heavy editing by multiple concurrent users. A consultant has been hired to recommend maintenance tasks. Which of the following is a critical, routine maintenance operation for an enterprise geodatabase that removes unreferenced states and moves entries from delta tables into the base tables to improve query performance?

Accepted Answer

Compressing the geodatabase

Answer

Compressing the geodatabase is the correct answer. The compress operation is essential for maintaining performance in a versioned enterprise geodatabase by removing unreferenced states and their associated delta table rows, and moving entries common to all versions into the base tables. This reduces the depth of the state tree that the database must search through for queries. While rebuilding indexes and updating statistics are also crucial maintenance tasks, they address different aspects of performance optimization (speeding up data retrieval and aiding the query optimizer, respectively). Shrinking the database is a file-level operation that reclaims space and is performed less frequently.

Question 3

A county's planning department maintains separate feature classes for 'Parcels' and 'Zoning'. To enforce data integrity, they need to implement a rule ensuring that every parcel polygon must be completely contained within a single zoning polygon. Which of the following geodatabase components and rules would be most appropriate to enforce this spatial relationship?

Accepted Answer

A geodatabase topology with a 'Must Be Covered By' rule

Answer

A geodatabase topology is the correct component for managing and enforcing spatial relationships between features. The 'Must Be Covered By' rule specifically ensures that features from one feature class (Parcels) are geometrically contained within the features of another feature class (Zoning). A relationship class links records based on attributes but doesn't enforce spatial containment. Subtypes categorize features within a single class, and domains restrict attribute values, neither of which can enforce this kind of spatial rule.

Question 4

Which of the following best differentiates geodatabase replication from versioning?

Accepted Answer

Replication creates full copies of data in different geodatabases for synchronization, while versioning manages multiple states of data within a single geodatabase.

Answer

The primary distinction is that replication is designed to distribute and synchronize copies of data across multiple geodatabases, which might be in different geographic locations. In contrast, versioning is a mechanism within a single enterprise geodatabase that allows multiple users to edit data concurrently without applying locks or duplicating data, by managing different 'states' or versions of the data.

Question 5

When designing a geodatabase schema, a GIS analyst needs to categorize a 'Roads' feature class into 'Highway', 'Arterial', and 'Local' types. Each road type must have a different default value for the 'SpeedLimit' field and a different set of valid materials in the 'Pavement' field. What is the most efficient geodatabase design element to achieve this?

Accepted Answer

Implementing subtypes based on an integer 'RoadType' field.

Answer

Subtypes are the most efficient method for categorizing features within a single feature class. They allow you to apply different default values and attribute domains to specific categories of features. In this case, subtypes for 'Highway', 'Arterial', and 'Local' can be created, and each subtype can be configured with its own default 'SpeedLimit' and its own assigned domain for the 'Pavement' field. This is more efficient than creating separate feature classes and provides more advanced behavior than a simple domain.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Geodatabase Design and Management Questions and Answers