The user can assign tags (both preset and user-definable) and perform queries by different criteria.
They may be used to gather runtime status reports, perform distributed queries or any other type of data collection where a persistent identifier is desired.
The database can be downloaded in its entirety, or one can perform limited queries using a web interface.
It provides a way for a software user to perform queries without having to know a query language (such as SQL).
On SourceOECD, they are accessible in their interactive form: the user can perform queries online.
Minimally, just about all of them support XPath for performing queries against documents or collections of documents.
The query language was designed to perform complex queries in as simple a manner as possible.
They were able to perform spatial queries and analyze neighborhood problems.
Kexi can be used for designing and implementing databases, data inserting and processing, and performing queries.
Many of these properties are exposed through regular expressions to perform complex queries on text.