the data base is loaded. Records can be added to and deleted from any of the data sets, but new data sets cannot be added, new relationships (linkage paths) cannot be established, and the disk storage area cannot
beexpanded without least partial regeneration of the data base, which entails reloading of all affected data files.
On
the whole, however, Total is one of the most ef-fective high-powered software systems in use today, and it is successfully displacing IBM's IMS-2 in numerous installations.
InSeptember 1972, Honeywell Information Systems announced an agreement to market the Honey-well Series 200/2000 version of Total through its own worldwide sales force, assuring further recognition and market acceptance for the already widely used Total system.
0~ generation stages. Master and variable-entry files cannot share the sarne I/O buffer. This facility for sharing I/O buffers provides the potential for saving a great deal of main memory space, but adds the burden of intelligent planning and possible future conflicts between space and performance as the applications processed against a data base grow and the combinations of files processed change.
Total allows you to set up a data base; it also provides the method for accessing the data base conveniently.
However, you must write the application programs that determine what information is to be retrieved, and how the information is to be processed, and must perform all procedural processing required to maintain the data base.
The three topics relevant to discussin!l what Total can do for' you are data base generation (DBGN), data base definition language (DBDL), and data management lan-guage (DML).
DATA BASE GENERATION: The DBGN program accepts the data base structural defmitions to DBDL and outputs an assembly language program. After assembly, this module is catalogued as a subroutine to be core resident with the application program. After executing the FORMAT program, which formats disk storage, applica-tion programs can be run which include one of the access phases as a subroutine. The first application program to be run must be one that loads data into the data base;
alternatively, the same program that normally would be used to add new records to a file can be used. It depends on the types of applications you are processing. Normally, there needs to be some sort of base to begin with.
Output from the DBGN program execution is a listing of the data base defInition statements which serve as a guide to the contents and structure of the data base records.
A randomizing algorithm is used to calculate master record physical addresses based on the value of the con-trol field. If duplicate addresses are calculated, a pointer is used in that record to show where the "duplicate" or . synonym record is stored. Thus, the complete disk space allocated can be used. Once all space is used up, the data file must be reloaded with new parameters.
DATA BASE DEFINITION LANGUAGE: Writin~ the control statements for structuring the data base IS not difficult. Essentially, it consists of a very short preamble identifying the data base by name and specifying whether concurrent update protection is required (to prevent con-flicts and errors due to two application programs modify-ing the file simultaneously in a multiprogrammmodify-ing environment) and descriptions of each single-entry and each variable-entry data set. The exact format depends on the operating system Total is to function under, but in general the total number of logical records, record length, number of records per block, and number of records per track must be specified for each data set.
A part of the description of each data set is the name of the I/O buffer, the names of all linkage fields, and the structure of the records. Total processes only fIXed-length records; i.e., all records in a data set must be Of the sarne length. Only one format can be specified in single-entry data sets, but multiple formats are allowed in variable-entry data sets, each identified by a two digit record code. Linkages between a single-entry data set and a variable· entry data set can be qualified by the record code, if desired.
Record structure is identified in a very straightforward manner by statin$ the name and size in bytes. No data format identification is required or can be specified. The data names refer to data elements, the smallest chunk of data that can be named for retrieval. Data elements may be subdefmed to a maximum of 32 levels of structure (comparing favorably with COBOL). The data elements mayor may not refer to individual fields used in an application program. For example, a complete data mi~t
be identified as a data element while the application program processed it as three fields (month, day, and year). Three separate elements could be ade out of the date if desired, but it would be unnecessary because the complete data is always transferred as an entity.
O>mments can be easily incorporated in the data defif'J-tion statements and are highly recommended to serve as ~
helps to application programmers. ~
DECEMBER 1972
©
1973 DATAPRO RESEARCH CORPORATION, DELRAN, N.J. 08075 REPRODUCTION PROHIBITED70E-132-01d Software
Total
Cincom Systems, Inc.
~ DATA MANAGEMENT LANGUAGE: DML provides the facilities for retrieving infonnation an;passing it to an application program, as well as for opening and closing program-ming language. For data transfer operations, the param-eter list includes an operation code, the name of the fde
The operation specified controls the parameters needed.
The exact procedures vary depending on the host pro-gramming language. The chief difference among the various languages supported is whether or not literals can be used in the parameter list.
A total of five sets of functions are provided: one for opening and closing fdes individually or via a list, one for serial retrieval of records from a single or variable entry file, one for resetting the serial record counters, one for working with single-entry (master) files and one for work-ing with variable-entry fdes. Under IBM's OS/360,
Serial processing of variable entry records can be accord-ing to actual layout on disk or accordaccord-ing to any linkage path. Nonnally this would mean that there is some order to the records. Serial processing provides some efficiencies when all records in a data set must be handled.
Processing functions available for master fdes include reading, writing, record addition, and record deletion_ All variable records linked to a master record must be deleted in a separate operation before a master record can be program other than identifying variable names where required. Because only a data element list is required in the CALL statement, modification of the data record structure to include new fields does not require that application programs referencing the affected files be changed. buffer sharing between files being accessed by multiple tasks and files being accessed frequently. Total 5/6 also provides transaction logging, including the "before" and
"after" images of modified data records. This allows the data base to be reconstructed if required.
Under Total 4, one record will be held for each fde until the record is written or another record is read. This prevents separate application programs from updating the same version of a record independently, which would cause the loss of a transaction. An application program attempting to access a fde already having a record being proceed will stall until the record is written.
Under Total 5/6, one record is held for each fde for each task. If subsequent access attempts to a "held" record cause application programs to stall, Total will monitor the occurrence of these attempts and will cause the record to be automatically released, allowing the application pro-gram to proceed, and a status indication will be returned to the first program indicating that reprocessing of the transaction involved is required.
A recently developed version, Total 7, provides additional facilities and increased modularity to Total 4. A Real-Time Version of Total 7 is scheduled to extend these facilities to on-line users. Both new versions will be avail-able in addition to Total 4 and 5/6.
PERFORMANCE: There are several aspects to evaluating the performance of Total. The basic ones boil down to efficiency of disk space utilization, speed of data access, and speed of loading data into the data base. It is not surprising to fmd these elements interrelated.
Data is distributed randomly based on a control field and when two records calculate to the same location, a secondary location is used. Thus, all disk space becomes closer to full, the occurrence of synonyms (identical addresses) will become more frequent. This discussion pertains only to master fdes because direct pointers are provided for access to variable-entry fdes. Synonyms are placed on the track (or cylinder) as the home record if possible. Cincom quotes an average of 1.1 seeks per record, an excellent figure.
HARDWAREiSOFTWARE REQUIREMENTS: Total 4 is currently operational on IBM System/360 and 370 operational on IBM OS installations.
The amount of main memory required by Total is
INITIAL DELIVERY: Early 1969.
CURRENT USERS: About 250 as of July 1972 __
©1973 DATAPRO RESEARCH CORPORATION, DELRAN, N.J. 08075 REPRODUCTION PROHIBITED
DECEMBER 1972
70E-132-02a Software
Environ/1
Cincom Systems, Inc.
MANAGEMENT SUMMARY
Environ/I is a modem data communications monitor and task management system that makes good use of some of the most sophisticated and up-to-date programming tech-niques to be found in today's software marketplace.
Importantly, Environ/I '8 LTlitial development strategy recognized that the EDP user community was heading toward an approach to data processing that would include integrated data bases, with data base/data communica-tions systems an important part of the ultimate picture.
Cincom is also the vendor of TOT AL (Report 70E-132-01), the leading alternative data base system to IBM's IMS. Thus, Cincom can supply a data base/data communications system that is integrated at the source and execution level for all users of IBM System/360 or 370 DOS, OS, DOS/VS, or OS/VS computer systems.
(For a comparative examination of data base/data com-munications systems, the reader should refer to Reports 70E491-01 and 70E491-02, on IBM's IMS and CICS, respectively, and also to other data base systems and communications control routines listed in the Index.) Cincom's position as a single source for a data base/ data communications (db/dc) software system considerably elevates the importance of Environ/I.
Typically, few data processing executives give proper recognition to the complexities of telecommunications when they develop their companies' plans for terminal-oriented computer networks or for distributed intelligence systems in which remote locations have processing capabilities that are tied together either by direct links or via a central processor. Many of the standard operating system facilities provided for the central computers require extensive interfacing in order to be operated from a remote on-line station. These communications-oriented considerations include system start-up and cycle-down, file and communication access methods interfaces, system recovery procedures, security measures, etc.
From an overall point of view, it is commonly desirable for telecommunications to be handled as one of a number of jobs under control of the computer's operating system, instead of dedicating an entire processor to controlling the multi-station network. As the number of terminals and concurrent tasks in a telecommunications network increase, the requirement for allocating and accounting for the system resources demanded by each user program becomes very complex. Solutions to resource contention depend upon the application of highly sophisticated programming techniques. These include the establishment and maintenance of message queues, assignable task priori-ties, program swapping into and out of main memory, sharing of common code through program "re-entrancy,"
etc. Furthermore, hardware changes to the central com-
1:>
Environ/1 is a communications monitor and task management system that runs on any System/3GO or 370 DOS, OS, or virtual storage system and uses advanced paging teChniques to achieve impressive periormance with compara-tively small main memory requirements. Its interface with Cincom's TOTAL elevates its importance.
CHARACTERISTICS
SUPPLIER: Cincom Systems Inc., 2181 Victory Parkway, Cincinnati, Ohio 45206. Telephone (513) 961-4110.
FUNCTION: Environ/l is a general-purpose data como.
munications monitor that operates in a partition or region of an IBM System/360 or 370 under DOS, OS, or their virtual storage counterparts to control multiple on-line user terminals and applications. By consolidating all of the com-munication interfaces and I/O and control functions requir-ed in the telecommunications network, Environ/l isolates the user's application programs from the communication environment. Environ/l also provides paged or "virtual memory" support for both COBOL and Assembly lan-guages, while FORTRAN and PL/ 1 are supported in a non-paged mode. Thus, on-line applications can be develop-ed without significantly greater diffICulty than development of. similar batch programs.
OPERATION: As the interface between user-written applications programs, the operating system, and com-munications requirements, Environ/l operates with the highest priority in a partition or region that contains about 30K. to 33K bytes for Environ/I, about 2K. to 3K bytes for each typical on-line application program, about 10K. bytes for message buffers and interface code for the terminals, and a 3K. to 5K "context" for each program that includes specific parameters for each user's version of that program.
Of particular significance in the operation of Environ/l is that only 2K. to 3K bytes of main memory are required for each user's version of an application program, no matter how large the program really is; and only 30K. to 33K bytes of main memory are required. to hold the resident portion of Environ/l 's several hundred thousand bytes of code.
These small main memory residence areas are made possible by extensive use of paging and a virtual memory mode of operation, not only for Environ/l 's own code, but also for user programs.
A variety of sophisticated techniques are employed that automatically divide each user's application area in main memory into 512-byte pages. Cincom notes that most com-petitive telecommunications monitOIS, including IBM's CICS, have been designed to handle pages from about 2K to 6K bytes in length, which creates an unnecessary overhead burden for data transmission and storage in an on-line environment. Also, studies made of on-line systems indicate that less than 10% of the code in most on-line programs is accessed more than 80% of the time; this makes it possible for very large programs to be executed efficiently from a much smaller area in main memory. Specifically, byallow-ing as much (or as little) as 10K. bytes of a Wier's program to reside in main memory, Environ/l provides good support for application programs that typically can be in excess of
lOOK bytes long. ~
MARCH 1974 ©1974 DATAPRO RESEARCH CORPORATION, DELRAN, N.J. 08075 REPRODUCTION PROHIBITED
70E-132-02b Software