GIS Geodatabase Design and Management 3 — Questions and Answers
Question 1: What is the role of the 'GDB_ITEMS' system table in an enterprise geodatabase?
- It stores spatial indexes for all feature classes
- It acts as the central catalog of all geodatabase datasets and their metadata (Correct answer)
- It logs all editing transactions performed by users
- It holds the projection definitions for coordinate systems
Correct answer: It acts as the central catalog of all geodatabase datasets and their metadata
GDB_ITEMS is the core system table that catalogs every item in the geodatabase, including feature classes, tables, domains, and topologies.
Question 2: A geodatabase subtype allows you to do which of the following?
- Split a feature class into multiple physical tables by category
- Assign different default values and domains per category within one feature class (Correct answer)
- Store features of different geometry types in a single class
- Enforce topological relationships between feature classes
Correct answer: Assign different default values and domains per category within one feature class
Subtypes partition a single feature class by a numeric code field, allowing different attribute defaults and domain restrictions per category without creating separate tables.
Question 3: Which privilege is required for a database user to create new feature classes inside an enterprise geodatabase owned by another user?
- SELECT on the owner's feature classes
- CREATE TABLE privilege in the DBMS (Correct answer)
- Explicit WRITE permission on the geodatabase connection
- No special privilege is needed beyond a valid login
Correct answer: CREATE TABLE privilege in the DBMS
Creating new tables (feature classes) in a relational database requires the CREATE TABLE privilege granted at the DBMS level.
Question 4: What is the function of a 'network dataset' in a geodatabase compared to a geometric network?
- Network datasets support turn features and multi-modal travel; geometric networks model flow direction in utility systems (Correct answer)
- Geometric networks support turn features; network datasets are for utility flow modeling
- Both are functionally identical but differ only in storage format
- Network datasets are only used for raster analysis, not vector routing
Correct answer: Network datasets support turn features and multi-modal travel; geometric networks model flow direction in utility systems
Network datasets (used with Network Analyst) model transportation networks with turns and multi-modal connectivity, while geometric networks model directed flow in utility infrastructure.
Question 5: In an enterprise geodatabase, what does 'reconcile' accomplish in versioned editing?
- It publishes edits from the default version to all child versions
- It merges changes from the parent version into the current editing version (Correct answer)
- It permanently commits edits to the base table
- It removes all edits made since the last save
Correct answer: It merges changes from the parent version into the current editing version
Reconciling a version incorporates changes that have occurred in the target (typically default) version into the edit version so conflicts can be identified and resolved.
Question 6: Which setting in a geodatabase feature class controls whether Z values (elevation) are stored and managed?
- Coordinate precision
- Has Z (Correct answer)
- Spatial reference vertical datum
- Feature class type
Correct answer: Has Z
The 'Has Z' property, set at feature class creation, determines whether three-dimensional elevation values are stored for each vertex.
Question 7: What happens to orphaned features when you delete the origin row in a geodatabase composite relationship class?
- Destination features are updated with NULL foreign keys
- Destination features are automatically deleted (cascading delete) (Correct answer)
- An error prevents deletion of the origin feature
- Destination features are moved to an error feature class
Correct answer: Destination features are automatically deleted (cascading delete)
In a composite relationship class, the destination objects are owned by the origin; deleting the origin triggers a cascade that also deletes all related destination features.
GIS Geodatabase Design and Management 3
What is the role of the 'GDB_ITEMS' system table in an enterprise geodatabase?