26,895 research outputs found
Implementation of the GOQL language
The Graphical Object Query Language (GOQL) is a
graphical query language that complies with the ODMG
3.0 standard and runs on top of the o2 DBMS. GOQL
provides users with the User's View (UV) and the Folders
Window (FW), which serve as the foundation upon which
end-users pose ad-hoc queries. The UV is a graphical
representation of any underlying ODMG scheme. Among
its advantages is that it hides from end-users most of the
perplexing details of the object-oriented database model,
such as methods, hierarchies and relationships. To
achieve this, the UV does not distinguish between
methods, attributes and relationships, it encapsulates is-a
hierarchies and it utilises a number of desktop metaphors
whose semantics can be easily understood by end-users.
The FW is a condensed version of the UV and provides
the starting point for constructing queries. In this paper,
we demonstrate the UV and the FW and discuss GOQL's
system architecture, its various components and the way
these components interact to generate the UV and the FW
and to provide an ad hoc query construction mechanism.
We also present the screen interface of the language
Object-oriented querying of existing relational databases
In this paper, we present algorithms which allow an object-oriented
querying of existing relational databases. Our goal is to provide an improved query
interface for relational systems with better query facilities than SQL. This
seems to be very important since, in real world applications, relational systems
are most commonly used and their dominance will remain in the near future. To
overcome the drawbacks of relational systems, especially the poor query facilities
of SQL, we propose a schema transformation and a query translation algorithm.
The schema transformation algorithm uses additional semantic information to enhance
the relational schema and transform it into a corresponding object-oriented
schema. If the additional semantic information can be deducted from an underlying
entity-relationship design schema, the schema transformation may be done
fully automatically. To query the created object-oriented schema, we use the
Structured Object Query Language (SOQL) which provides declarative query facilities
on objects. SOQL queries using the created object-oriented schema are
much shorter, easier to write and understand and more intuitive than corresponding
S Q L queries leading to an enhanced usability and an improved querying of
the database. The query translation algorithm automatically translates SOQL queries
into equivalent SQL queries for the original relational schema
A rapid prototyping/artificial intelligence approach to space station-era information management and access
Applications of rapid prototyping and Artificial Intelligence techniques to problems associated with Space Station-era information management systems are described. In particular, the work is centered on issues related to: (1) intelligent man-machine interfaces applied to scientific data user support, and (2) the requirement that intelligent information management systems (IIMS) be able to efficiently process metadata updates concerning types of data handled. The advanced IIMS represents functional capabilities driven almost entirely by the needs of potential users. Space Station-era scientific data projected to be generated is likely to be significantly greater than data currently processed and analyzed. Information about scientific data must be presented clearly, concisely, and with support features to allow users at all levels of expertise efficient and cost-effective data access. Additionally, mechanisms for allowing more efficient IIMS metadata update processes must be addressed. The work reported covers the following IIMS design aspects: IIMS data and metadata modeling, including the automatic updating of IIMS-contained metadata, IIMS user-system interface considerations, including significant problems associated with remote access, user profiles, and on-line tutorial capabilities, and development of an IIMS query and browse facility, including the capability to deal with spatial information. A working prototype has been developed and is being enhanced
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