L. A. Rowe and K. A. Shoens. Data abstraction views and updates in RIGEL. In P.A. Berstein, editor, Proceedings of ACM SIGMOD International Conference on Management of Data, pages 71--81, Boston, Mass., May-June 1979.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....by evaluating expressions in the relational algebra over relations and markings. Relational update operators almost identical with those in Pascal R are available. Unlike Pasal R, the foreach statement in PLAIN is consistently defined to be applicable to all structured variables. ffl RIGEL [RS79]extends Modula [Wir77] with relation, view, and tuple types. An expression that produces sequences of values, called a generator, is defined which integrates relational query expression with the for statement to provide a consistent form of iteration. The language also provides a data abstraction ....

L. A. Rowe and K. A. Shoens. Data abstraction views and updates in RIGEL. In P.A. Berstein, editor, Proceedings of ACM SIGMOD International Conference on Management of Data, pages 71--81, Boston, Mass., May-June 1979.

....view updates, additional semantic information must be provided by the definer of the view. One approach is to require that each collection be opaque which might become a view at a later time. In this case there is a group of functions through which all accesses to the collection are funneled [ROWE79], and the view definer must perform program maintenance on each of these functions. This will entail substantial program maintenance as well as disallow updates through the query language. Alternately, it has been shown [STON90B] that a suitable rules system can be used to provide the necessary ....

Rowe, L. and Shoens, K., "Data Abstraction, Views and Updates in RIGEL," Proc. 1979 ACM-SIGMOD Conference on Management of Data, Boston, Mass., May 1979.

....identities that allows persistent database objects to have an existence independent of their values. Some extensible database projects, such as 2 [12, 17, 39, 44, 45, 48] also have similar goals. O is in the same spirit as the work done in designing database programming languages, such as [7, 10, 19, 37, 43, 46, 47, 49, 52]; it strives to be the single language for data definition, data manipulation and general computation to avoid the problems arising out of impedance mismatch [19] O also shares the concerns of the persistent programming languages, such as [6, 16, 38, 40 42] persistence is a property of ....

....deliver them in the right order for the for loop. 9. The square brackets [ and ] indicate an optional item. The suchthat and by clauses are based on similar clauses in SQL [18] and Concurrent C [27] Similar for loops have been provided, among others, in Pascal R [47] Rigel [43], Plain [52] and Trellis Owl [38] and Vbase [7] 9 3.1.1 Iterating Over Cluster Hierarchies Clusters mirror the hierarchy relationship of the corresponding types. If type x is derived from type y, then the corresponding clusters also have the same relationship. It is sometimes necessary to ....

[Article contains additional citation context not shown here]

L. Rowe and K. Shoens, "Data Abstraction, Views and Updates in RIGEL", Proc. ACM-SIGMOD 1979 Int'l Conf. on Management of Data, Boston, Massachusetts, May-June 1979, 77-81.

....the database and the programming language this gap is often described as # Now at Bell Communication Research, Morristown, N. J, 07960 1 an impedance mismatch [CoMa] Yet, the approach favored by previous researchers has been that of interfacing relational DBMSs to traditional languages [RIGEL, Sch77] More recently, major e#orts have been made to integrate databases and programming languages under the Object Oriented paradigm [KiLo] These approaches tend to abandon relational databases in favor of an object oriented one often supporting a limited query capability and the navigational query ....

Rowe, L. and K.A. Shones, "Data Abstraction, Views and Updates in RIGEL", Proc. ACM SIGMOD Int. Conf. on Management of Data, pp. 71-81, 1979.

....and use any join algorithm that it determines to be optimal. 6. In O , angle brackets denote a set. The suchthat and by clauses were inspired by similar clauses in SQL [14] and Concurrent C [18] Similar for loops have been provided, among others, in Pascal R [31] Rigel [28], Plain [37] and Trellis Owl [23] Multiple loop variables in for loops are also allowed in Rigel [28] 4.3 Recursive Queries When iterating over a set or a cluster, we allow iteration to also be performed over the elements that are added during the iteration, which allows the expression of ....

.... denote a set. The suchthat and by clauses were inspired by similar clauses in SQL [14] and Concurrent C [18] Similar for loops have been provided, among others, in Pascal R [31] Rigel [28] Plain [37] and Trellis Owl [23] Multiple loop variables in for loops are also allowed in Rigel [28]. 4.3 Recursive Queries When iterating over a set or a cluster, we allow iteration to also be performed over the elements that are added during the iteration, which allows the expression of recursive queries [3] Thus, given a class person with a set component named children, the following ....

[Article contains additional citation context not shown here]

L. Rowe and K. Shoens, "Data Abstraction, Views and Updates in RIGEL", Proc. ACM-SIGMOD 1979 Int'l Conf. on Management of Data, Boston, Massachusetts, May-June 1979, 77-81.

....form of iterator that yields the results of a database query. Examples include Pascal R [Schm77] Plain [Wass79] and O [Agra89] These languages allow the programmer to write arbitrary i loops, but i functions can be specified only implicitly via predicates over sets of objects. Rigel [Rowe79], another DBPL, offers a more general design; it allows both implicit i functions, for iterating over built in container types (such as lists, arrays, and sets) and programmer provided i functions. In comparing E to these languages, recall that E was intended to be a systems programming language, ....

....defined. Pascal R [Schm77] introduced relation as a type constructor; tuples could be added or deleted under program control, although the relations themselves could only be named variables. One implication of this restriction is that nested relations were not allowed. Other DBPL s, e.g. Rigel [Rowe79] and Plain [Wass79] took a similar approach with similar restrictions. PS Algol [AtkM83] the first language providing fully general (orthogonal) persistence, made the runtime heap the basis for persistence. Any object reachable from a distinguished database root pointer would persist. However, ....

Rowe, L., and Schoens, K., "Data Abstraction, Views, and Updates in RIGEL," Proc. ACM SIGMOD Conf., 1979.

....be addressed. A second approach is to start from a database system and build into it a rich type system and other useful programming notions such as recursion and higher order functions, to make the database system have enough power to cope with complexities inherent in engineering environments [Shoens79, Stonebraker84, 86a, 87]. A third approach is to define new database programming languages from scratch. These database programming languages typically are rich in data structuring capability, versatile in data persistence and complete in computing power [Albano85, Cardelli84, Ohori89] 12 Object oriented programming ....

Shoens, K. A. and Rowe, L. A., "Data Abstraction, Views and Updates in RIGEL," Proceedings of the ACM-SIGMOD International Conference on the Management of Data, 1979.

....the database and the programming language this gap is often described as Now at Bell Communication Research, Morristown, N. J, 07960 an impedance mismatch [CoMa] Yet, the approach favored by previous researchers has been that of interfacing relational DBMSs to traditional languages [RIGEL, Sch77] More recently, major efforts have been made to integrate databases and programming languages under the Object Oriented paradigm [KiLo] These approaches tend to abandon relational databases in favor of an object oriented one often supporting a limited query capability and the navigational query ....

Rowe, L. and K.A. Shones, "Data Abstraction, Views and Updates in RIGEL", Proc. ACM SIGMOD Int. Conf. on Management of Data, pp. 71-81, 1979.

....2 Old Problems and New Opportunities The impedance mismatch problem is deep rooted in cultural and technological issues that have prevented the transfer to the commercial world of early research results aiming at solving the problem. Among the early attempts by database researchers, we find RIGEL [RoSh] and Pascal R [Schm] which focused on a better fusion of procedural languages and relational systems, and thus inherited the limitations of the relational data model. There were also several attempts from the programming language camp, which focused primarily on adding persistency to existing ....

Rowe, L. and Shoens K., "Data Abstraction, Views and Updates in RIGEL," Proc. ACM-SIGMOD Int. Conference on Management of Data, Boston, MA, 1979.

....(Furnace) Figure 7: Shared object relations. ######################################################################## two environments as specified by type conversion catalogs. Most programming language interfaces to database systems do not store type mapping information in the database [Ale85, Ale78, Ate83, Mye85, RoS79, Sch77]. We are maintaining this information in catalogs so that user defined data types in the database can be mapped to the appropriate Common Lisp data type. The type mapping information is stored in three catalogs: TYPEMAP, OFTOPG, and PGTOOF. The TYPEMAP catalog specifies a type mapping and ....

L. A. Rowe and K. A. Shoens, "Data Abstraction, Views, and Updates in Rigel", Proc. 1979 ACM-SIGMOD Int. Conf. on the Mgt. of Data, Boston, MA, May 1979.

No context found.

Rowe L.A. and K.A. Shoens [79], "Data Abstraction, Views and Updates in RIGEL", Proc. of ACM SIGMOD Conference, Boston, Mass., 71-81, 1979.

No context found.

L. A. Rowe and K. A. Shoens, "Data Abstraction, Views, and Updates in RIGEL", Proc. 1979 ACM-SIGMOD Intl. Conference on Management of Data, ACM, New York, 1979.

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