SASI ACCESSoo to DB2m software for Decision Support in a Large Industrial Organisation (Conversion,Experienees,Enbancements).

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1 SASI ACCESSoo to DB2m software for Decision Support in a Large Industrial Organisation (Conversion,Experienees,Enbancements). P van Kleef, Hoogovens Umuiden, The Netherlands Abstract Hoogovens IJmuiden are an integrated steel company, in which very modern steel technology is coupled to a high degree of automation. Decision Support is very strategic. The base architecture has been formed by DB2 of IBM for the storage of the data and by the software of SAS Institute for the exploitation of the. data. Hoogovens IJmuiden is using the combined power of IBM' DB2 and SAS. It is used bya large community of business professionals. The presentation gives an overview of the experiences in this area and explores the enhancements and requirements, which are put forwared to SAS Institute. Hoogovens Organisation Hoogovens Groep is an internationally oriented company with a revenue of 4 billion dollars. 28,000 employees are working for companies in many European countries and in the United States. This private company is one of the most modern European producers of high quality steel and aluminium. Besides these basic activities Hoogovens Groep is engaged in Technical Services, Industrial Supply, Steel Manufacturing, Trading and other activities. Hoogovens Groep has the strategy to deliver to the most critical clients in a technologically fast developing market. Research, product development, process improvements and co-makership do have a central place in the sales strategy for all companies of the Hoogovens Groep. Hoogovens IJmuiden are one of the companies of the Hoogovens Groep BV. Hoogovens IJmuiden are settled in IJmuiden at the North Sea coast near Amsterdam. The company has a revenue of 2 billion dollars and produces 5 million tons of crude steel. A total number of 16,000 people is employed with the company. Hoogovens IJmuiden are an integrated steel company. All activities, from the supply of raw materials, coal and ore, up to the delivery of the final products, are taking place in one location, covering an area of 2,000 acres (800 hal. The complete production process is executed in a series of factories. A continuous flow of material runs between the various production plants. Production is a complex technological and orderbased process, being very characteristic for the company. There is a large flow of information, parallel to the flow of material. Information Systems, architecture To manage the flow of information the company has developed an information system architecture, based on a functional hierarchy of computers in 4 levels. For each of the 4 distinguished levels a set of production process functions has been defined, specific for that level. level 1: contains the functions for order acceptance and processing and the mid-term planning functions. level 2: contains the functions, which refer to the installation planning and the logistic processes of a specific production area. level 3: contains the functions for running a single plant, installation or storehouse. level 4: contains all the process and installation or instrumentation functions. The exchange of information between functions from different levels is "top down" and."bottom up". A horizontal flow of information between the processes at the same level also exists. There is an overlapping level, in which the functions are embedded on behalf of reporting and analyzing of all production I": -","' t" "'"

2 processes. These Reporting and Analysis Systems (RAS) are basic for decision support and management information. The level 1 and 2 functions are implemented on two IBM mainframes, with IMS and DB2 as database management systems and System Network Architecture (SNA) for the communications. The level 3 and 4 functions are mostly implemented on PDP-11 and VAX computers from DEC and DECnet for the communications. DECnet and SNA networks are interconnected via a gateway, which enables communication between DEC and IBM domains. Op.ratlonal BYltem. la,.rad,truot... of I,,'ormallon.yetame has the strategy to do processing on the PC as much as possible and to use mainframe capacity mainly for queries on databases in the data warehouse and for heavy or special processing tasks. The Host/workstation connection is effected by a glass fibered tokenring structure. The selection of the proper end user tools has a longterm impact on the environment of enduser computing and decision support. Enduser tools that are strategic for Hoogovens IJmuiden are: - Query Management Facility and Interactive Chart Utility for data selection and reporting on the mainframe platform. - software of SAS Institute for all kinds of data selection and reporting on mainframe and PC platform. - Lotus 123 for reporting on the PC platform - Rbase, mainly for local or departmental systems on PC's. For the PC platform PS/2's with a processor are the current standard and Windows 3.0 has been chosen as a new standard for the user interface. Decision Support, strategy The decision support strategy is strongly based on end user computing and development by business professionals. The role of the information systems department is restricted to: - architectural matters. - delivery of information (company data), in a form which enables the professional to use that information for his business functions. selection of and support for software tools enabling the enduser to extract information from corporate databases. - supplying facilities to the end user necessary to support the software and assuring that these facilities meet high standards of reliability and availability. In accordance with these policies the so called "data warehouse" concept has been adopted, in which all company and business relevant data are available. For both performance and cost reasons the company SAS & DB2, "installed base" The mainframe environment at Hoogovens is based on two IBM mainframes, an IBM model J and a IBM , working with the operating system' MVS/ESA. On both systems the DB2 version 2.2 relational database management system has been installed together with Distributed Data Facility and the Data Propagator product of IBM. April '91 about 750 production tables and 1200 end user tables in the DB2 363

3 environment for operational systems, and production tables and 8800 enduser tables in the DB2 environment for Reporting & Analysis IRAS) are available. Altogether representing 40 Gigabytes of DB2 data. Production tables are grouped in 90 application systems. The following SAS modules are available for the end user: SAS/ASSIST, SAS/GRAPH, SAS/AF, SAS/FSP, SAS/IMl, SAS/OC, SAS/ETS, SAS/ACCESS to DB2, SAS/IMS-DL/I, SAS/DB21*). With exception of the modules for accessing databases, the same m()dules are installed both on mainframe and PC platform, which enables the end user to run his application on the platform, that services him best. In the DEC domain mainly the base module and SAS/GRAPH are installed to report on INGRES databases. About 150 business professionals are active in developing SAS applications for their own use and for some 1000 endusers. The major purpose of these applications is for decision support. Considerable effort is invested in departmental or local systems. The SAS community at Hoogovens altogether owns about 4000 SAS libraries and an unknown number of SAS applications. One can estimate that an active SAS enduser spends 20 hours/week at developing or maintaining. SAS applications. This implies for 150 users with 40 working weeks I year and an hourly rate of $ 50 in a 6 million dollar budget. Hoogovens has applied SAS since Conversion VS/V6, overall experience The majority of the applications has been developed with mainframe version 5 software. May '90 version 6 was installed for the MVS systems, which was recommended by the lis department for the following reasons: - Version 5 libraries do have the ancient BDAM-file architecture. This file architecture is for several years no longer strategic in IBM's future plans and for that reason not fully supported by IBM's new System Managed Storage ISMS). - Same version at all hardware platforms. - Increased functionality. However, version 6 is not fully upwards. compatible with version 5 of the SAS software. A time consuming conversion is necessary. Summary of the experiences at Hoogovens IJmuiden: - Functionally there are no difficulties in converting Base, FSP, OC and Graph. applications, including formats, macros and libraries. A serious cost problem is the increase of the CPU consumption, which is estimated to be % on the IBM mainframes. SAS/AF applications can be converted by using PROC V5TOV6, but the final result is in many cases hardly a maintainable product. Endusers are advised to rebuild their applications instead of converting them. SAS/IMS is not available in version Therefore one has the option of doing nothing and waiting for the next release or the option of isolating the IMS-part and converting the remaining part into version 6. A first impression of the new SAS/ACCESS to DL/1 suggests that a conversion is necessary anyhow; - The Micro-To-Host-Link brings along a nice experience. No problems, faster and consuming less CPU in a token ring or coax PC/Host connection. SAS/ACCESS to DB2 instead of SAS/DB2. These modules are completely different. Although the direct accessibility of the DB2 tables is a strategic improvement of the product, the module is not capable enough for applications with multi table SOL queries. There are also some shortcomings in specific features. The incompatibility with version 5 and the laborious route of applying the irreplace- 364

4 ".),' able qualities of the DB2 optimizer in processing multi table SOL queries cause the enduser a time consuming conversion. Altogether the module is hardly acceptable for the end user. SASI ACCESS to DB2, the less ej\joyable part. Combining tables in a SOL query is synonymous for using relations and for that reason the essential part of every relational system. Each supplier of a relational system is concerned to optimize the process of combining tables, especially when those tables are large. The optimizer of a relational system is in many cases an excellent model of an expert system. The DB2 optimizer is one of those excellent models. With the version 5 DB2EXT procedure the SAS end user indeed had. the possibility to develop multi table SOL queries, fully processed by the DB2 optimizer. With version 6 SAS/ACCESS to DB2, the SAS enduser in many cases is forced to create DB2 views for multi table SOL queries. These DB2 views have to be created by the database administration (DBA) department with the necessary access and view descriptors and with all the granting activities. For maintenance reasons it is not recommended that an individual end user creates the DB2 views by himself. Besides, when the enduser would have the possibility to create the view, he may not have the authorization to do the granting on the view created, based on the complex authorization model of DB2 and IBM's security software Resource Access Control Facility (RACF). For each DB2 table or view in use by the SAS community, at least one access descriptor and one view descriptor has to be created and maintained. It is strongly recommended to put the responsibility for the creation of the descriptors at the database administration department. But creation of access and view descriptors can only be done online in the ACCESS procedure, meaning a lot of dull and fault promoting labour for the specialists of the database administration department. If the database administrator is responsible for creating access and view descriptors, then he is also responsible for translating a lot of DB2 column names into SAS variable names. Using the FSEDIT or FSVIEW procedure for updating DB2 tables with a primary key, gives -535 SOL return code, implying that it's not allowed to update a primary key column, even if one did not change that column. This problem prevents the conversion of some SAS/AF applications, that use FSEDIT on such a table. The problem is registered in number V6-ENGINE of the SAS usage notes. The corresponding advice to create a DB2 view without the primary key columns is not very useful. In most cases those columns are essential for the application. The version 6.06 access descriptor has not been prepared for the distributed environment of DB2. The access panel doesn't contain a parameter field for the location of the distributed DB2 table. Furthermore, there is the rigidity of holding the DB2 SSID in the acces descriptor, forcing one to create as much access and view descriptors for a single DB2 table as there are DB2 subsystems. DB2 tables may contain columns bigger than 200 characters, SAS can not. This problem is also registered in the SAS usage notes. The missing value in SAS is not the same as the NULL value in DB2 and it is not conform to the specifications of the ANSI2 standard. Particularly in the SOL language the NULL value often is a reason of misunderstanding. SASI ACCESS to DB2, in practice. At Hoogovens the database administration department is responsible for creation and maintenance at least one access and view descriptor for each DB2 production table and view. The database administrator creates the acces descriptor with the "assign =yes" parameter, forcing SAS to generate the 8 character variable names. 365

5 All descriptors are created into two SAS libraries, corresponding to the two DB2 subsystems. When an end user starts a SAS session with the intention to make use of the data in a specific DB2 subsystem, he automatically gets the proper library allocated by filling the SSID in a startup parameter. The libref of the library has the same name as the authorization identification of the production tables, making the conversion of the queries slightly easier. The information centre gives assistance in conversion of applications by: organizing workshops presentations (monthly local SAS usergroup meeting) helpdesk support planned and occasional conversion support planned conversion projects Endusers, who build their own applications, are responsible for maintaining those applications and are for that reason also responsible for the conversion effort. Endusers are strongly advised to make use of the acces descriptors, created by the DBA-department, particularly when they want to create their own view descriptors with the purpose of subsetting or excluding variables. Some central organisation within their own department for creation and maintenance of the view descriptors is strongly recommended. Endusers are advised to specify so-called "SAS DB2 views", which are DB2 views with 8 character column names. The database administrator creates those views and the referencing descriptors. When a version 5 DB2EXT application has to be converted, a thorough analysis of the SQL query and the effected DB2 data is necessary. The analysis focusses on questions as: how many DB2 tables are effected in the SOL query how large are those tables (how many pages) who is authorizing (granting) those tables which parts of the WHERE-clause refer to inter table relations and which to inner table relations. Number of tables There are no serious problems with a single table query. See SUGI 15 papers for conversion of SAS/DB2 applications (*). With multi table queries one should distinguish between queries on small tables (less than 10 pages of 4 kb) and queries on large tables. Size of tables Queries on small tables can be converted straightaway, using SAS for optimization and neglecting the qualities of the DB2 optimizer (1). For queries, referring one or more large tables, a DB2 view must be created together with the necessary SAS access and view descriptors. The subsequent conversion of the application is straightforward. But, depending on the particular authorizations upon the tables it is not always possible to create a DB2 view. Creation and authorisation of the tables: If all tables are production tables, the enduser may ask the database administrator to create the view and the referencing access and view descriptor. He also may ask the "owner" of the data for the grants on the new created view. If all tables are end user tables from one creator (which is not always the "owner"), the creator can do the job. If the application happens to be a mixture of end user and production tables (which often is the case), neglect the conversion, keep using version 5.18 and formulate a complaint to the SAS representative of the organization. WHERE-clause relations: The WHERE clause should be analyzed to distinguish the statements, that refer to inter table relations (join/union/sub-selects)' and the statements, that refer to inner table relations (select, project). The join and subselect should always be part of the DB2 view, that has to be created. A DB2 view cannot be created using a union. One may transform the union into an "OR" statement and then create the DB2 366

6 :; r [,; I " t f: r,-. I C' f : :rj h y j; i; }< ).r: y,.? i", [;. ';' 1", '.' ]i f: '{, r. r: ", view,,trusting the DB2 optimizer to be smart enough to transform it backwards into a union. In specific applications the union can be handled by the SAS optimizer. Inner table relations may be part of the DB2 view, but they may also be put into a subset of the view descriptor or in a separate WHERE clause in the converted SAS application. It is not always obvious which option should be taken. Enhancements Allow the Engine Manager to analyse a data request in such a way, that all related elements for a specific database engine, are extracted and put forward to that specific engine for processing by the optimizer of the corresponding DBMS. It should be possible to convert a SOL query in the DB2EXT procedure straightforward in PROC SOL query with some minor changes for table-names into view descriptors. In PROC FSEDIT/FSVIEW, allow update of all columns in a DB2 table excluding the primary key columns. Mark the primary key columns in the screen as non-updateable. Extend the DB2 acces descriptor with the location part of the DB2 table name for use in the distributed environment of DB2. The use of access and view descriptors should not be restricted to the DB2 subsystem, at which they are created. The SOL of SAS is close to the ANSI2 standard. It would be very helpful if processing of the NULL value by PROC SOL corresponds with the same standard. Bibliography 1.SUGI 15 papers for conversion SAS/DB2 applications. - Converting SAS/DB2 Applications from version 5 to version 6. Bradley W Klenz - SAS Institute Inc. - Writing efficient SAS/DB2 applications in version 6 of the SAS system. Charles A Jacobs III - SAS Institute Inc. - Performance Considerations for the Database Engines. Howard Plemmons Jr.- SAS Institute Inc. - SAS Software and IBM's DB2: an enduser computing strategy. T Miron - System Seminar Consultants. For more information, contact: P van Kleef Information Systems and Automation P.O. Box CA IJmuiden - The Netherlands Tel: Fax: SAS, SAS/ACCESS, SAS/AF, SAS/ASSIST, SAS/ETS, SAS/FSP, SAS/GRAPH, SAS/IML, SAS/IMS-DL/I, SAS/OR, SAS/OC, SAS/ST AT are registered trademarks of SAS Institute Inc., Cary, NC, USA. SAS/CALC, SAS/CONNECT, SAS/DB2 are trademarks of SAS Institute Inc., Cary, NC, USA. Database 2 (DB2) is a registered trademark of the IBM Corporation, Armonk, NY, USA }. r... k ft >, ; ;; :;; :,, 1.'.;-: '.;;:' <.:;l, t. \: 367