Spatial databases and SQL Flashcards
1
Q
When would a file-based approach be preferred over a database based approach?
A
- single user
- small data
- low cost for simple projects
2
Q
How are geometries typically stored in spatial DBs?
A
-as a field data type in a table w the object’s attributes
3
Q
What are some examples of SQL standards?
A
- ANSI-1986
- ISO-1987
4
Q
What is data definition language?
A
-statements that define a DB’s structure. i.e. CREAT, DROP, etc
5
Q
What is data manipulation language?
A
-statements that manipulate records from tables. i.e. SELECT, UPDATE, etc
6
Q
List the logical operators and comparative operators
A
logical: AND, OR, NOT, IN, BETWEEN
comparative: IS, LIKE
7
Q
What are aggregate functions?
A
-fast calculations for values of a specified field. i.e. MAX, AVG, MIN. etc
8
Q
What services can metadata provide?
A
- documentation
- inventory
- catalog (provides structured search and comparison of help geospatial resources by others)
