DR4 Help
 Archive Intro
 Table Descriptions
 Schema Browser
 Introduction to SQL
 Sample SQL Queries
 Query Limits
 How To
 SkyServer Sites
 SkyServer Traffic Page
 Web Browsers
 Site News
 Contact Help Desk

secondary object The best observation of an object with multiple observation is called the primary object, and other observations are stored in the PhotoObjAll table and PhotoObj view as secondary objects.