A SELECT * statement returns all the properties identified in the expected
content class list for the specified
folder. When constructing this list of properties to return, the schema scope
for the folder is used. If any required schema definition items are not present
within this schema scope, only the default properties for items are
returned.
Similarly, sending a PROPFIND Method using the
WebDAV protocol with a depth of 1 to find all item properties returns only
the properties defined by the expected
content classes of the folder.
Using SELECT * can be an unnecessarily broad use of a Structured Query Language (SQL) query and may return information that will not be used
by the application. In most instances, queries with specified property names and other search criteria will provide better results.
Using SELECT * also results in the
Exchange store having to
look up the schema for item being searched so that it can determine which set of properties to return. This schema lookup can be expensive
and may constitute a large part of the search process.