A query is a search on the database for objects that meet the specified criteria. The query is formulated by an individual and, in MQL, it must be saved for subsequent evaluation. A user has access only to queries created during a session under that user's own context. It is then run or evaluated and the 3DSpace finds the objects that fit the query specification. The found objects appear on the screen or are listed in MQL. If the found objects are often needed as a group, they can be saved in a set which can be loaded at any time in the session or MQL session under the same context.
Important:
Queries that might hit foreign vaults should be enclosed in transactions (start trans; ...; end trans;) to prevent locking problems.