The data elements for a column of a table are fetched from irregular address locations in memory and stored as vector data with a regular address increment. Vector designating data is also generated which includes at least the first element address of the stored vector data and the increment of the vector. The vector data is processed by a program routine which can perform the processing required by a selected command and which includes vector instructions each designating at least one set of vector data elements to be executed, in such a manner that vector data elements are fetched successively from the data storage device and are supplied successively to a pipelined arithmetic or logical operation unit.
Apparatus used in a relational data base system to maintain a dependence between a user-defined field in a row of one base table and the state of a set of rows in another base table. There are three kinds of dependent fields: a count field which contains a count of the rows in the set, a sum field which is the sum of a field in the rows of the set, and a base copy down field, which is a field in the rows of the set which contains a copy of a value in a field in the row of the one base table. The two base tables make up a referenced-referencing pair and the row from the one table has a primary key which is used as a foreign key in the set of rows of the other base table. The apparatus consists of components in the data dictionary which define the user-defined dependent field and the nature of the dependence, including any conditions thereon, and components in the data base system's run time system for maintaining the dependence. Each time the state of a row in the referencing base table is altered, the run time system uses the data dictionary to determine whether there is a user-defined dependent field, and if there is, what kind of dependent field it is. Code in the run time system then reestablishes the dependence as required for the altered row.
A page-accessing method in a segmented tablespace 10 which eliminates unnecessary reading and locking. The tablespace comprises data pages 18 grouped into identically-sized segments 16, each segment storing data for a single table. A status indicator 26 for each data page of a segment is kept in a separate segment control block 20 stored on a space map page 14. Five data page status indicator values are maintained: (1) FULL (26a) - entirely full of current data; (2) PARTIALLY FULL (26b) - partially full of current data; (3) UNFORMATTED (26c) - empty; contains no data; (4) MASS DELETE (26d) - contains only obsolete data because of an unqualified deletion (mass delete) of data; or (5) QUALIFIED DELETE (26e) - contains only obsolete data because of a qualified deletion of data. When scanning over the data in a segment, UNFORMATTED and MASS DELETE pages are skipped. QUALIFIED DELETE pages are locked, and then skipped if they still contain only obsolete data when the lock is obtained. When inserting data into pages, preliminary reads of UNFORMATTED and MASS DELETE pages are avoided. Data integrity is ensured by placing integrity checking bits at the beginning and end of each page. If the bits contain the same value, the page's data integrity is intact. If the bits are different, the page's previous consistent contents are recovered from the log records.
A method, apparatus, and article of manufacture for handling access to multiple file-systems from a program written in a high-level language such as COBOL, programming language compilers and run-time environments. More specifically, the present invention provides a computer-implemented method for supporting multiple file-systems in file input/output (I/O) operations. As a result, an object program has access to different file-systems without recompilation. Further, the interfaces within the source language are independent of the specified file-system, so that support of any number of different file-systems can be accomplished with relative ease. In addition, the ability to dynamically select a file-system on a file-by-file basis is provided, thereby allowing the program to use a first file-system for one file and a second file-system for another file.
A method and system are provided for direct marketer personnel to enhance query performance. The query is performed on modified relational database data stored as contiguous data fields across all records in the database. The queries are performed using a process called bitmapping. A bitmap is a series of computer words strung together in a one dimensional array. It looks at data as a series of bits rather than a higher level data type such as an integer or floating point value. The system also provides the ability to provide a system that permits data segmentation, ad hoc requests, and systematic research. The system is also capable of producing a suite of reports that are specific to the needs of direct marketers. These include reports on RFM information (recency of last purchase, frequency of purchases, and monetary totals of life to date information. These reports are generated on a regular (usually monthly basis) and are used to drive the direct marketing process.
A method, apparatus, and article of manufacture for handling access to multiple file-systems from a program written in a high-level language such as COBOL, programming language compilers and run-time environments. More specifically, the present invention provides a computer-implemented method for supporting multiple file-systems in file input/output (I/O) operations. As a result, an object program has access to different file-systems without recompilation. Further, the interfaces within the source language are independent of the specified file-system, so that support of any number of different file-systems can be accomplished with relative ease. In addition, the ability to dynamically select a file-system on a file-by-file basis is provided, thereby allowing the program to use a first file-system for one file and a second file-system for another file.
