MDBS APPLICATION PROGRAMMING REFERENCE MANUAL -

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(1)PROGRAMMING. MDBS APPLICATION. REFERENCE MANUAL. -. The MDBS DMS MANUAL Version. Micro. Data. 3.08. Base Systems, Inc.. P. O. Box Lafayette,. 248. Indiana. 47902. USA Telex:. (312). 209147. 303-6300. ISE. UR. (in Illinois). December. 1985. Copyright Notice This entire. employees. Inc. . ,. and. agreement. (C). .. is provided for the use of the customer and the customer 's have been copyrighted by Micro Data Base Systems, entire contents reproduction by any means is prohibited except as permitted in a written with Micro Data Base Systems, Inc. manual. The. COPYRIGHT. 1981. Micro. Data. Base. Systems,. Inc.. Rev.. 85A 3250332.

(2) NEW. RELEASES,. VERSIONS,. AND. A WARNING. of the magnitude of the MDBS software will necessarily continue to evolve over time. ReaHzing this, Micro Data Base Systems, Inc., vows to provide its users with updates to this version for a nominal handling fee.. Any programming. endeavor. versions of MDBS software will be considered as separate products. bona fide owners of previous versions are generally entitled However, to a preferential rate structure.. New. Finally,. of our software is personalized to identify the some of licensee. several levels of this personalization,' methods be which involve encryption guaranteed to combinatorially Our products have been produced with a very decipher. difficult to investment of capital and labor, to say nothing of the substantial years of prior involvement in the data base management area by our we Accordingly, concerned about any principals. are seriously unauthorized copying of our products and will take any and all available legal action against illegal copying or distribution of our products.. (C). each copy There are. COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. ".

(3) MDBS. DMS. MDBS. MANUAL. DMS. MANUAL. PREFACE. application developers were well aware of the the miá-1960s, data handling limitations of programming languages and file management To overcome these limitations, data base management systems systems. approaches to data base By 1971, began four major to appear. shallow-network, had management the hierarchical, taken shape: approaches structuring CODASYL-network and logical data to relational, Each and manipulation. represented an advance over the old fileoffered oriented data handling methods and the latter two approaches advances over the former two. By the mid-1970s, data base management software was well established as the cornerstone for application development and some mini computers. on mainframes By. microcomputers end of the decade, with their computing basis -- -- began to dollar power on a per The acceptance of mainframe data base management systems proliferate. coupled with the rise of microcomputers led to the formation of Micro Data Base Systems in both Incorporated by a group with expertise make qenl1ine management base The data objective was to areas. in This objective was tools available in the micro realm. and viable data 1979 with the release of MDBS I authentic the -- microcomputers. Over the years, base management system (dbms) for which operates not only on has evolved into the present MDBS this microcomputers The evolution of machines many as well. but on larger. the. Near phenomenal. initial. fulfilled. first III. with micro dbms is highlighted with many firsts: first a and implementation of logging recovery, first full dbms micro dbms, dbms, postrelational to run first first multiuser MDBS. built-inIII under. PCDOS,. MSDOS. and UNIX.. MDBS Today, offers professional application developers a degree and of power unavailable with any other data base be management software This is minis or mainframes. on micros, -due implementation proprietary to the highly efficient, partially MDBS techniques. is not a mainframe retread shoehorned into a microcomputer. is also due to the innovative data modeling Because these features go far beyond features that MDBS provides. MDBS those of the older data base management approaches, is variously referred to as postrelational multiarchical extendedor or The emphasis in this approach network. to data base management is on The result natural representation of the application world. direct, As stated in the is a tremendous increase in developer productivity. DApt'ÁhÁqe r.he 7"Ñí generÁr.ic)n· authoritative qtAfe of fjie Arr. pepc)rt. 1982): L. Gradwell, Pergamon press, Oxford, England, (ed., D.. IIIflexibility it It III III. III. j.. "The. data modelling capability of MDBS other commercially available DBMS." MDBS that is, in many ways, ahead of mainframe gradwell). III is issuperior III DBMSs.""... (D.. All. of this translates into developers and administrators.. (C). COPYRIGHT. 1981. convenience. Micro Data Base Systems,. for. Inc.. a. application. to any product. j.. L.. system. Rev.. 85A. _.

(4) mdbs. dms. manual. mdbs. Dl4S. manual. The MDBS R&D Lab's expertise in the areas of decision support unique systems and artificial intelligence has resulteá in two environments for processing MDBS data bases. One is a decision support environment called Kmwledgeí·iam functions as a universal It knowledge management system, allowing users to represent and process knowledge in many different ways spreadsheets, text, -- including graphics, forms, procedural models, data bases, and relational MDBS The second data bases. postrelational is a revolutionary wakes Guru. environment called the artificial of intelligence and both technology language expert system benefits natural processing easily accessible to business users, without sacrificing familiar business computing capabilities. FIDBS III data base contents are directly accessible within the Guru environment.. III. III. It. This manual provides details on the features and utilization of Companion manuals Language. Data fianipulation discuss the I·1DBS Data and various optional modules. Language This Description manual is not intended to be a tutorial. For a tutorial treatment of s (including many advantages over f lle data base management management), the reader is advised to consult such suitable references the. l<DElS. it. as:. l.. i'iicrQ nAt'AhAse l'1AnAqpmenr, pra'w im'íl Tpchniq\Íes H. c(qt.ion Dpve1Apm.enr by r. Bonczek, et. al, New York, 1984. Academic Press,. 2.. "A. l, 3. 4. Perspective on Data Models,". pc Tech jc)l1rnÁ1. Mr. 53CC. P. 1984.. .. "Fiicros Get Mainframe Data Vol. 3, No. 5, 1984.. Scheme,". .. "Uniting Relational and Postrelational Tools," sYsrems arrí ,qoftware,, Vol. 3,. sY5r.elAs. No.. Áñá. t\pp1. i-. pages,. vol.. 2,. No.. 8oftwa.rp,!. Database bianagenent 1984.. li,. coverage to date of f irst reference provides the most definitive the postrelational approach, comparing and contrasting it with the That book also includes four oláer data base management approaches. !·ÍDI3S is through your usage. extensive examples of available It III Í4DBS, For many from from the publisher, Inc. orI'ÍDBS local bookstore, seminars has Company in training offered practical years, the III major cities and at customer sites.. The. Rev. .. 85A. (C). COPYRIGHT. 1981. i·licro Data Base Systems,. Inc.. -.

(5) MDBS. DMS. MANUAL. MANUAL. The. Inc. commitment to customer success does not stop with innovation, quality and support. The Company offers a full consulting and application development services to clients regional offices in the Dallas its regional Chicago and its Services include: areas.. software range of through New. MDBS. DEIS. York. l. 2. 3 4. .. . .. I'IDBS,. application. Customized. Customized. Knowledgeí·lan. systems development using application MDBS and/or the. Communications. Special specific. design. systems. interfaces. training. application. on. a. III. including mainf rame-wicro links wide. systems,. of topics including variety HDBS programming,. III. C. and Guru usage 5. .. Guru,. tools. General consulting including hardware/software recommendations. feasibility. usage,. studies. and. experienced, professional staff handles consulting and application and development needs of some of the world's largest corporations has developed very extensive micro application governments. systems in such diverse areas as cash management, strategic planning, human resources and management, administration, waste disposal these distributed service support. In many cases, application systems have involved multiuser processing or mainframe-micro links.. The. It. (C). COPYRIGHT. 1981. blicro Data Base Systems,. Inc.. Rev. .. 85A.

(6) .. MDBS. DMS. MDBS. MANUAL. DEIS. MANUAL. Table of Contents PREFACE CHAPTER A. b.. I.. OVERVIEW. . . . DRIL. Organization The Role of. . .. . .. . .. . .. . .. . .. in Application. . .. CHAPTER II. GENERAL BACKGROUND A. Data Transferral . . . . . . . B Currency Indicators. . . . . . . C Classes of D!4L Commands. . . . . D. . E . F .. CHAPTER A . B .. a. B.. CHAPTER. a. B.. CHAPTER A . B .. CHAPTER A . B .. FIND COMMANDS. III.. Overv iew. .. .. .. Details. Comnaaná. . .. . .. . .. . .. . .. V. MODIFY COMMANDS Overview . . . . . . .. Details.. Command. .. VI. ASSIGNMENT Overview . . . .. Details.. Command. . . .. . . .. .. CHAPTER. a. B.. .. .. . .. .. CHAPTER A B. (C). . .. . .. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. .. .. .. .. .. .. .. .. Development. . .. Comrtíand. .. .. .. Details.. VIII.. CONNECT. Command. Details. Overview. Command. . .. . .. . .. . .. . .. .. .. .. .. . .. . .. . .. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. Command. Command. . .. Details.. Details.. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . .. . .. . .. Command. Details.. 1981. Micro. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . .. .. . .. . .. . .. . .. . .. . .. . . .. .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. .. .. .. .. .. .. COMMANDS .. D. COMMANDS. .. Details.. XII. BOOLEAN Overview . . .. . .. COMMANDS. X. DELETION COMMANDS Overview . . . . . . . . .. COPYRIGHT. . . .. . .. . .. Data. . .. . .. . .. . .. Base Systems,. Inc.. l l l. -. 3 3 3. 5 5 8 9. . . .. COMMANDS. CHAPTER XI. UTILITY COMMANDS Overv iew . . . . . . . . A. B. . .. . . .. CREATION COMMANDS. VII.. Overv iew. CHAPTER IX. DISCONNECT Overview A. . . . . El. . .. Stating . . . . l·lultiuser Environment. . . . . Protecting Data Base Consistency against External Factors. . . . . . . . . . . Command.. DML. a. CHAPTER IV. RETRIEVAL COMMANDS Overview A. . . . . . . . . . . Command B. Details. . . . . . . CHAPTER. . .. Rev.. 85A. lili 12. 29 29 3 O. 33 3 3. 34 39 39 40 53 53 54 57 57 57 59 59 59 63 63 63 67 67 67 81 81 8 2. i.

(7) MDBS. DMS. MANUAL. 14DBS. DEIS. MANUAL. Ea= CHAPTER XIII. SPECIAL Overview A. . . . Commaná B. Details.. COMMANDS .. CHAPTER XIV. MULTIUSER Overview A. . O . . Command B. Details. CHAPTER RECOVERY XV. Overview A. . . . . Command B. Details. CHAPTER. TABLE. . .. .. .. .. .. . .. XIV"1: tiultiuser. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. .. Locking. . .. . . .. . .. .. . . .. . . .. . . .. . .. . .. . .. . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. .. . .. . .. . .. . .. . .. . .. . .. . . .. . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. .. . .. . . .. . . .. . . .. . . .. .. . .. . . .. .. .. .. .. .. .. DESCRIPTIONS. STATUS .. . . .. COMMANDS. COMMANDS. Status Details. Command. B.. . .. LOCKING. COMMAND. XVI.. Overview. a.. . .. . . .. . .. . .. . .. . .. . .. . .. Contention Protocols.. .. .. 89 8 9 89 93 9 3 9. 5. lOl. 101 102 107 107 107 94. APPENDIX A. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. A-l. APPENDIX B. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. T. .. .. .. .. .. .. B-l. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. COMMAND GENERAL. ii. Rev.. INDEX INDEX. 85A. .. (C). COPYRIGHT. 1981. Ezicro. Data. Base Systems,. .CI-l .GI-l. Inc..

(8) DMS. MDBS. COMMAND. MANUAL. DMS. MDBS. MANUAL. CLASSIFICATIONS ÉácLQ. ASSIGNMENT. COMMANDS. oft run unit to Data base key). . . of run unit based on MeInber) . . . (8et (Set of run unit to ]$[ull) . . . . . . . of run unit based on Qwner). . . . (8et (Set of run unit based on user indicator) (Save Qata base key for Qirrent of run unit). . (Set Member based on Cwxent of run unit) . . . (Set Member to current of run unit (£xception)) (Set ELe1Tber based on Member). . . . . . . . . . (,aet Member to fiull). . . . . . . . . . . . . . based on Qwner) . . . . . . . . . . (Set Member (Set Member based on Eser indicator). . . . . . (Set Qwner based on Current of run unit). . . . (£et Qwner to current of run unit (Exception)). (Set Qwner based on Member) . . . . . . . . . . (Set Qwner to Elull) . . . . . . . . . . . . . . (Set Qwner based on Qwner). . . . . . . . . . . (8et Qwner based on lZser indicator) . . . . . . (Set user indicator to Current of run unit) . . (Set ¶ser indicator to E!ember). . . . . . . . . (áet Aser indicator to HUD. . . . . . . . . . (Set LLser indicator to Qwner) . . . . . . . . . (Set Rser indicator to user indicator). . . . .. (Set. SCD SCM SCN. seo SCU SDC SMC SME SMM. spin SMO SMU SOC SOE SOM SON SOO SOU. sue SUM SUN SUO SUU. BOOLEAN AÑM. (Añd of (AM of (And of (And of (eXclude (eXclude (eXclude (eXclude. Members with Members) Members with Qwners). Qwners with Members). Qwners with Qwners) . Wembers from Members). Members from Qwners) Qwners from MeInbers) Qwners from Qwners).. (Lnsert Uember into 8et). (Lnsert Qwner into Set) .. lOS. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . .. 40.1 40.1 40.2 40.2 . . . . . . . . . . . . . . . . . . .. 41 41 42 43 43 44 44 45 46 46 47 47 48 49 49 50 50 51 52. . . . . . . .. . . . . . . . .. . . . . . . . .. . . . .. . . . . . . . .. . . . . . .. .. .. .. . .. . .. . .. .. . . .. . . . . .. .. .. .. .. . . . . . . . .. . .. . .. . .. . .. . .. . .. .. .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. . . . . . . . .. . . . .. .. . . . . . . . .. .. . .. .. .. . . . . . . . .. 82 83 83 84 85 86 87 88. . .. . .. .. . .. . .. . .. . .. . .. .. .. 57 58. COMMANDS. CRA CRS. (C). . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . .. COMMANDS. IMS. CREATION. . . . .. COMMANDS. AMO AOM AOO XMM XMO XOM XOO. CONNECT. Current Current Current Current Current. COPYRIGHT. (Cxeate. Becord. Greate Eecord. 1981. Micro. in Area) . 8tore). and. jjata Base Systems,. Inc.. Rev.. 85A. 54 55. iii. -.

(9) MDBS. DMS. DELETION. MANUAL. (IZelete. Qelete. DISCONNECT. Record Eecord. that is Current) that is Member) . that is Qwner) .. all all. RSÉ4. RSO. MANUAL. 63 64 65. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . . . . . . . . . . . . . . .. . . . .. . . . . .. . . . .. . . .. G. ©. 0. C. G. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .. O. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. 28.1 28.2 28.3. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. . . . . . .. COMMANDS. (Bemove fiember froríi Set) (Bemove Qwner from Set) (EeInove Bet MeInbers) (Bemve Set Qwners). RMS ROS. Dl4S. COMMANDS. (Qelete Record. DRC DRE! DRO. . . . .. . . . .. . . . .. . . . .. 59 60 60 61. COMMANDS. FIND. (Eind (Eind (Eind (Eirúí (Eind. FDRK. ffm. FEO FPS FLÍ'Í FLO FÉ4I F81SK. Member) Qwner) .. . . . . . Urst . . . . . Eirst aequential record) Eirst Member). j¿ást. (Eind (Eind (Eind (Eind (Einá (Eiñd (Eind. . .. 0. .. .. O. 0. *. 0. 0. 0. .. . . . e. .. . . . . . . . .. . . . . . . . .. . . .. . . .. ©. O. e. G. j',ember based on data ítem) © Kerber based on Sort [[ey) . Eext L1enber) . . . . . . . . Next áember based on data Ltem) 4ext l1elTber based on Sort Key) . Next Qwner) . . . . . . . . . . Next Qwner based on data ítem) 0 (EiU Eext Qwner based on ,áort Key) . (Eind Eext ,aequential record) . . . . (Einá Qwner based on data Ltem) . . . (Eind Qwner based on Sort U}') . . . . (EÁnd Etüor Member) . . . . . . . . . (Eind 2rior Éáerrlber based on data Ltera) (Eind 2rior Llember based on Sort %ey) (Eiñd 2rior Qwner) . . . . . . . . . . (Einá Erior Qwner based on data Lten'.) (Eind Erior Qwner based on Sort Key). (Eiñd Record based on calc Key) . . .. FNI'.II FNFISK. fno. FNOI FNOSK FNS. FOl FOSK FPt.l FPMI F!¥1SK FPO. FPOI FPOSK. frk MODIFY. Quplicate Record based on calc Key). (EiM Last Qwner). FN!·1. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . .. O. . . 0. . . .. e e G. @. 12 13 14 14 15 15 16 17 18 19 19 20 21 22 23 24 25 26 26 27 28. COMMANDS. (2ut data into (Eut data into (Eut data into (EñT data into data into (E9T data into. PFC pF!q PEO PUTC PUTI·1 PUTO. iv. !4DBS. Rev.. (=. 85A. (C). Ueicí of Current of run unit) Eield of Member) . . . . . . EidLd of Qwner) . . . . . . . Current of run unit) . . . . KeTaber). Qwner). COPYRIGET. . .. . .. . .. 1981. . .. . .. . .. . .. . .. . .. . .. . .. l'licro Data Base Systems,. 34 34 35 35 36 37. Inc.. ".

(10) MDBS. DMS. MULTIUSER MAU MCC MCF MCP MRTF MRTP MSF MSP. RECOVERY. LOCKING. (Multiuser (Mültiuser (Multiuser (Múltiuser (Multiuser (Multiuser (Multiuser (Mültiuser. (LoG start of ComELeX transactions) (LoG ENCL compleá transactions). . (LoG EILE specification). . . . . (LoG buffer El,úSH) . . . . . (LoG UJ& ]y[eSsage). . . . . . . . (EXe-Lmage Eile Declaration). . . AEoRT) (TEansaction . . . . . . . (=ansaction BeGiN) . . . . . . . (=ransaction CQélmit) . . . . . .. LGFILE. file. LGFLSH. lgmsg PIFD TRABT TRBGN TRCOE4. .. .. .. .. .. . . .. . .. . .. . . .. . .. .. .. .. .. . . .. . .. .95. . . .. 96. .96 .97. ". 98 98 99 99. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. . . . . . . . . .. .105 .106 .102 .103 .103 .104 .104 .105 .106. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . .. COMMANDS. GETC GETM GETO GFC GFM GFO ODRK OF'M OFO OLM OLO OMI OMSK ONM ONMI ONMSK ONO ONOI ONOSK OOI OOSK OPM OPPII OPMSK OPO OPOI OPOSK ORK. (C). indicators) . . . Count). . . . . . run unit Eree) . . run unit Erotect). Becord Type Eree). . . . . . Eecord jype Erotect) . . . . Set Eree). . . . . . . . . . Set Erotect) . . . . . . . .. Active Qser Gontention >rrent of >rrent of. COMMANDS. LGCPLX LGENDX. RETRIEVAL. MANUAL. DMS. MDBS. MANUAL. COPYRIGHT. from Current of run unit) . . . . from Member). . . . . . . . . . . from Qwner) . . . . . . . . . . . (Get Eield from Current of run unit). . . . (Get Uekí from Member) . . . . . . . . . . (Get Eield from Qwner). . . . . . . . . . . (Qbtain Duplicate Record based on calc Key) (GET (GEE (GET. data data data. (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Obtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain (Qbtain 1981. Eirst Qwner). Urst Member). Me1nber). j,ast Last Qwner). .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . .. . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . .. based on data ftem). Member based on Sort Key) . Next fjember). . . . . . . . Next MeInber based on data Ltem) Next E1elnber based on 8ort Key). Next Qwner) . . . . . . . . . . Next Qwner based on data ítem). Next Qwner based on Sort Key) . Qwner based on data ítem) . . . Qwner based on 8ort Key). . . . Erior Member) . . . . . . . . . 2Uor Member based on data Ltem). MeTnber based on 8ort Key) . 2rior Qwner). 2Uor . . . . . . . . . . 12rior Qwner based on data Lteni) . Erior Qwner based on Sort Key). . Eecord based on calc Key) . . . . Member. Micro. Data. Base Systems,. Inc.. . . . . . . . . . . . . . . . . . . . . .. Rev.. . . . . . .. 30 30 31 31 32 32. 32.1 32.2 32.3 32.4 32.5 32.6 32.7 32.8 32.9. .32.10 .32.11. .32.12 .32.13 .32.14. .32.15 .32.16 .32.17. .32.18 .32.19 .32.20 .32.21 .32.22. 85A. v.

(11) MDBS. DMS. SPECIAL. MANUAL. (ÁLíTer Eñd Qfi ,aet). . . . (IZata Base control system (Qata 2ase SEl,ection) . .. dbinit DBSEL. .. .. .. .. .. .. .. .. DMSSJP EXTEND MPL SETPBF. undef. varcs. . . . . . . . .. . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . .. .. .. . . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . . .. . . . . . . . .. (Allocate Aser Lndicators). . . . . . . (Check Qirrent of run unit against Yser. .. .. .. .. .. .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . .. . . . . . O . . . . . . . . . . . . . ·. . . . . . . . . . . . . . . . . . .. INITialization). data block) . . . . . (wis Set JimE). . . . . . . . (FYTFNP data block) . . . . . (Mu1tiuser Eriority j,evel). . (SEE Eage BuEfer region). . . (TjNr)EFine data blocks). . . . (miable for Command átatus) (PFFTNF. DEFINE. . . .. 89 90 90. 90.1 90.2 90.2 . . .. 91 92 92. 92.1. COMMANDS. AUI CCU DBCLS DBCLSA DBCNV DBENV. dbopn DBOPNA DBSAVE DBSTAT GMC GOC GTC GTM GTO NCI TCN TCT TMN TMT TON TOT TUN. vi. MANUAL. COMMANDS. ALTEOS. UTILITY. DMS. MDBS. Rev.. (Oata Base CCLoáe) . . . . . (Oata Base CL,oáe for Area). (pata Rase format CoNyersion) (Qata Base ENYironment) . . (Oata j3,ase QEeN). . € . . . (Oata Base QEeli Áxea) . . . (Oata E,ase . . . . . (Oata Base . . (Get fjember Count). . . . . (Get Qwner Count) . . . . . (Get Type of >rrent of run (Get Type of fjember). . . . (Get Type of Qwner) . . . .. .. .. . . . . . . . . .. . . . . . . . . . .. . . . .. . .. . .. . . .. unit). B. . . . . .. . . . . . . . . . . . . . .. (Null all >rrency Lñdicators). (Tfst Current of run unit for Eiull) (Fest Current of run unit Type) . . (Test Member for NUI). . . . . . . (Tést Member Type). . . . . . . . (Tést Qwner for tiull) . . . . . . . (Tést Qwner rype) . . . . . . . . . (Test Yser indicator for NullA . .. 85A. (C). COPYRIGHT. G. 1981. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . .. indicator).. Micro Data Base Systems,. . . . . .. 67 68 69 70 70. 70.1 . . . . . . . . . . . .. 71 72 73 74 75. 75 76 76 77 77. 78 78. 78.1 . 78 78.2 78.2 . 79. Inc..

(12) MDBS. DMS. MDBS. MANUAL. MANUAL. OVERVIEW. I.. a.. DMS. Organization. is the second component in the This is the MDBS DMS Manual. It MDBS Manuals and Reference assumes the reader is familiar with set of Manual. the MDBS DDL This in presented description data facilities and document Data Manipulation Language (DML) describes the MDBS command base DML data has each behavior of the the on the effect that The MDBS DMS Manual is written (MDBS.DMS). system on two control fundamental manipulation manipulation features and advanced levels: An is sufficient for features. understanding of the fundamentals The advanced features are developing useful application systems. perhaps These are denoted by a vertical bar in the outsiáe margin. needed, special less frequently but they are valuable for certain kinds of data manipulation.. III. in this manual is applicable to both versions describes those data manipulation features that of the host Version 3a. is also independent languageHost language(s) selected to interface with mdbs.dms. dependent aspects of the interface are described in appropriate MDBS System Specific Manuals. The documentation A 3a and 3c. Appendix are applicable only to. It. remainder of this chapter outlines the role of MDBS.DMS (DML), and Language Data Manipulation in software its associated background development. Chapter provides the detailed application that is necessary to effectively use the MDBS Data Manipulation Each Chapters Language. through XV documents a class of DML of commands. The commands individual in each class are presented When command a and each is described. alphabetically the function of command DML MDBS.DMS is executed, reports on the status of that command's Each possible command execution. status is explained in Chapter XVI. Tlíe. II. III. b.. The Role. of. DML. in Application. Development. Data Manipulation Language consists of a group of A DML of which performs some data manipulation task. command The programming is stated within an application program. language used to write an application program is called the hzak command 1(Ínql1(aqe. a DML is typically invoked as a function in the when a DML command host language. is given, the MDBS.DMS software. The commands,. MDBS. each. carries out the actual data manipulation. This could involve storing data from a host program variable into the data base. Conversely, could involve extracting data from the data base and depositing in Many a host language variable. other kinds of data manipulation are supported. In effect, the DML extends the data handling capability of language, a programming bases so that programs can utilize MDBS data in addition to traditional files.. it. it. Usage of the MDBS DML depends QIÜY upon a knowledge The application programmer need. searching (C). COPYRIGHT. indices, 1981. in developing an application program of the data base's logical structure. not be concerned with using pointers, disk I/O, file handling, free space management,. Micro. Data. Base Systems,. Inc.. Rev.. 85A. l. ".

(13) MDBS.DMS. MANUAL. - I:. OVERVIEI·I. -. IQJBS.DMS. MANUAL. etc. All of these factors are automatically handled by the I'IDBS.DE1S software. Furthermore, all data manipulation occurs subject to the in a data base's DDL security and integrity constraints defined MDBS.DMS a specif ication. multiuser environment, In manages record lockout to prevent such problems as one user attempting to modify a record that another user is reading. Special DÍ4L commands are available to the application programmer who (beyond the standard passive lockouts) desires to actively lock out records, record types[ or sets. data manipulation language provides a procedural approach to be contrasted data manipulation. can therefore with a query a language, which provides nonprocedural approach to data the highest manipulation. From the standpoint of achieving performance for application software, using a DML is inevitably On the other hand, superior to using a nonprocedural query language. the application developer who is not experienced in using DEIL can very achieve by using a nonprocedural query more rapid development likely language (at the expense of a sacrifice in perll'-Xmance). In data base management systems that do not support both a DI4L and a query language, the application developer has no choice. Both kinds of languages recommended that the query is are available with FIDBS. be used in situations where the lanquage (see the MDBS QRS Manual) It need flor rapid development outweighs the need for optimal perforr.íance. performance is the overriáing consideration, then the MDEIS If optimal DML most is appropriate. In addition to QRS, there are other optional modules IBS, RDL and BLF. IDML, including access A. It. Although the MDBS DML makes many commands available, is the case that an application developer will need to use only typically a few kinds of DML commands in any given application Across program. DML a a about dozen application is there small of programs, group all commands that tend to be heavily used. Varying degrees of selective MDBS.DL4S used linking are permitted, depending on the host language (see MDBS System Specific Manuals for details). In other words, only of 14DBS.DI4S to execute an application that part DFIL that is needed commands program's is held in main meiaoryú Since the entire !4DBS.DMS software is not in main memory, there is more memory available for a larger appliCation program or a larger page buffer region.. it. component of FIDBS.DMS performs virtual buffer paging, based When a algorithm. page replacement on an enhanced least-recently-used MDBS.DMS DML command images executed, determines whether of is needed pages are not resident, needed pages are in main memory. !4DEIS.DMS has them read into main memory. Tíie larger the page buffer main is that needed pages are memory, region in the more and the Thus be. processing is important resident the Faster a the application developer to allow as large page buffer region for environment, the page buffer region as possible. In a single-user One. all. If. likely it will. it. assigned by the programmer. In a multiuser size is directly EÍDBS.DPIS determines the size of the page buffer region environment, by all users that i s shared i .e . , simultaneously executing programs) (. application. 2. Rev.. 85A. .. (C). COPYRIGHT. 1981. Micro Data Base Systems,. Inc.. -.

(14) MDBS. DMS. MDBS. MANUAL. Data. MANUAL. GENERALBACKGROUND. II. A.. DMS. Transfer. data from a host language variable into the data Others retrieve data from the data base into a host language variable, from which the data can then be used for There are two basic approaches for computation or program output. MDBS.DMS to accomplish the data transferral between a data allowing The approach used depends base and an application program. on the Non-record-oriented nature of the host programming language. Host languages (such as BASIC) require the data block approach. languages with a facility for defining program record types (e.g.r COBOL, PL/l, PASCAL) use the program record type approach. Füll details of the approach used for a particular host language appear in the MDBS System Specific Manual for that host language. Some. DML. commands. pass. base.. ElQgks. A data block is a named sequence of one or DML commands MDBS host language variables. exist to define, extend, and undefine data blocks (see Chapter XIII). a given host language variable can participate in many data A DML command to put data into a data base has a blocks. data block name as one of its arguments. The value(s) of the host language variable(s) for that data block is(are) put into the data base. ADMLcommandto retrieve data from a data base has a data block name as one of arguments. The retrieved value(s) becomes the new value(s)itsfor the data block's host language variable(s).. l.. Rata more. 2.. elq9lmd BegQrg Typq,s. A program record type plays the same role as a data block. It is a named sequence of one or more host language variables. is not defined with DML commands, but is specified with the host language's facility program record types (for example, a Dl level for defining or a record entry in a COBOL working storage section, A given host language PASCAL). of variable or structure usually cannot participate in more than one program record A DML command to put data into a data base has a type. The record type name as one of its arguments. program value(s) of the host language variable(s) that program for A DML commaná record type is(are) put into the data base. to retrieve data from a data base has a program record type The retrieved value(s) name as one of its arguments. becomes the new value(s) of the program record type's host language variable(s).. It. C. B.. Currency. Indicators. iÁÁicátQts are used by of which record occurrences maintains two interest. MDBS.DMS a schema: in data base's specified the cuixent id£iÜ2qL of the set. Cjjll£1jgy. track. (C). COPYRIGHT. 1981. Micro. Data. an application programmer to keep in a data base are currently of currency indicators for each set the cutxent qwrrl of the set and There can be many owner record. Base Systems,. Inc.. 3.

(15) MDBS. DMS. MANUAL. - II:. BACKGROUND. MDBS. -. DMS. MANUAL. occurrences in the data base for a given set. At any moment during the execution of an application program no more than one of those owner record occurrences is the csuxmt owner of the set. dml commands allow the application programmer to control which (if any) owner record occurrence is the current owner of a set. The SXSTEM LéQQKjj QggyKKeÁge ia aluavs the cjjtr£nt qwijal q£ 2y£ly sYskelD=Qwneg made be (unless sek to is explicitly null by the programmer). member be can many there record Similarly, occurrences in the data base for a given set. At any moment during the execution of an one of those member record application program, no more than DML member. commands the set's allow the mirrent occurrences is any) member programmer which record to application control (if occurrence is the current member of a set.. it. As soon. set,the. DML. as can. a. record occurrence. becomes. be used:. the current. of. owner. a. to find any of its related members through that set (Chapter III), to modify its data values (Chapter V), to retrieve its data values (Chapter IV), from the data base (Chapter X), to delete the record occurrence etc. As soon as be used:. a. record becomes. the current. member. of. a. set, the. IJML. to find any of its related owners through that set (Chapter to delete the record from the data base (Chapter IX), to modify its data values (Chapter V), to retrieve its data values (Chapter IV), etc.. can. III),. Another kind of currency indicator that can be used during data manipulation is called the CjjttMjt Q£ the ljji) jjjjit. A run unit is an There are many record executing instance of an application program. data a base. At moment during the execution of an any occurrences in than application program, no more in the entire one record occurrence data base is the current record of that run unit. The current of a found by the that was mostDMLrecently run unit is typically the record by commands the allow the run unit). application program (i.e., application programmer to control which (if any) data base record is the current of run unit. As soon as a record becomes the current of run unit, the DML can be used: to delete the record from the data base (Chapter to modify its data values (Chapter V), to retrieve its data values (Chapter IV).. IX),. These can be any a data base schema has five sets. Suppose N: N: M sets. N, An mixture of l: application program can make I: There use of any of eleven currency indicators. are five current owner indicators (one per set), five current member indicators (one per set), and the current of run unit. In a multiuser environment, each application program that is using this data base will have its own eleven currency indicators.. l,. 4. l,. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. -.

(16) MDBS. - II:. MANUAL. DMS. BACKGROUND. MDBS. -. DMS. MANUAL. to the three kinds of currency indicators already addition MDBS allows an application programmer to optionally define of an application scope currency indicators within the additional be used No than 255 In. mentioned,. user-defined currency indicators can These additional within an application program. currency indicators employed to "remember" can be usefully the current owner of some set, The same before processing causes that current owner to change. and members be applied the current of run principle can DML commandsto current used be processing to in can Various subsequent unit. access the remembered record. DML commands are also provided for the user (i.e., application programmer) to define additional currency indicators and to make the record that is a set's current owner (or member or current of run unit) the current record for a user-defined currency indicator. program.. more. All currency indicators are null when an application program begins execution, except the current owner of each system-owned set and the current of run unit, which also has the SYSTEM record as its current record. A currency indicator remains null until a DML command is executed to change it. C.. Classes. The has one. DML. of. DML. Commands. commanás. fall devoted to. chapter classes is as follows:. into thirteen classes. Each command class it. The order of presentation for these. Finding records (Chapter III) (Chapter IV) Retrieving data from records Modifying data in records (Chapter V) Assigning currency indicators (Chapter VI) Creating records (Chapter VII) Connecting records (Chapter VIII) Disconnecting records (Chapter IX) Deleting records (Chapter X). Utilities Boolean. (Chapter. XI). operations (Chapter XII) Special operators (Chapter XIII) Multiuser locking (Chapter XIV) XV) Recovery operators (Chapter. The the. within a given class are presented alphabetically in chapter for that class. In becoming acquainted with this manual, is recommended that these chapters be examined in sequence. Also, the reader may want to ignore the advanced manipulation features on the initial pass through this manual. DML. commands. it. D.. Stating. Each mnemonic. a. DML. Conunand. command consists of a short mnemonic. For instance, the is used for Finding the first újember record connected to A the current owner of a set. of zero, one, two, or three arguments is stated along with a DML command. An argument is either a DML FFM. list. (C). COPYRIGHT. 1981. >. Micro. Data. Base Systems,. Inc.. 5. -.

(17) MDBS. DMS. MANUAL. - II:. BACKGROUND. MDBS. -. DMS. MANUAL. set name, record type name, area name, data item name, or data block/program record name. For example, FEM needs a single argument: a set name, to indicate for which set we want to find the first member. Correct usage of a DML command depends on a knowledge of the kinds of arguments required by that commaná. If one of the arguments record), the application programmer must program is a data block (or the be aware of whether command will use the data block's variables as inputs or outputs. command can use currency indicators and can change currency An application programmer must know which currency indicators. a DML command can use and which currency ináicators indicators can (and the the of alterations) nature . alter A. DML. it. Command. Status. execution. The. of a DML command always results in aO cQIuDang command through status is an integer in the range from Státjjá. 2 55. The command status number is returned as the value of a host A command status of O language choosing. variable of the programmer's A completetL means that the execution of a command was successfully command status of 255 means that the data manipulation system tried to by the command, but that the find a record occurrence indicated does Any indicated record occurrence not exist in the data base. the command command execute did not normally. other status means that Generally speaking, this is caused by either faulty logic of the programmer, a mis-statement of the command, an attempt to violate or integrity constraints specified in the DDL, failure to security A have a needed disk on-line, or a hardware malfunction. detailed command Chapter each such XVI. description of status error appears in A. Comnand. Form. employed for stating a DML command depends on The MDBS System Specific Manual for a the host language being used. given host language shows the syntax for using DML within that host The. precise syntax. language. interfaces: a). There. are flour. C). d). categories of host language. DML invocation ith direct some some Data block oriented with indirect DML invocation (e.g., BASICS) Record oriented with direct DML invocation (e.g., C, PASCALS, PL/l) Record (e.g., oriented with indirect DML invocation COBOLS) PASCALS,. Data. block. FORTRANS,. b). major. oriented. w. BASICS). (e. g.. ,. some some some. some. does not allow program host language is data block oriented be Invoking a record oriented. is said to record types; otherwise, DML a DML command directly means that the host language allows a mnemonic be treated as host language function. This is not to. if it. A. it. 6. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. _.

(18) MDBS. DMS. indirect. allowed in the. arguments case the ED. =. where. case,. are. parameters of command has the. FFM. ("arguments"). FFM. BACKGROUND. - II:. MANUAL. a. DML. MDBS. -. mnemonic and For instance,. function. following generic form: a. MANUAL. OMS. associated its the direct. in. ". is a host language variable that receives the command status value returned by the FFM function. In the indirect case, the FFM command has the following generic form: where. ED. ED. where. ED. returned. ("FFM,arguments"). OMS. =. is. host. a. by the. language. DMS. function. variable that receives the command status as a result of executing the FFM command. String. Command When. a. quotes is string are. command is stated, the portion called the command string.* Two separated by. a a a. Two. DML. of that command within elements in a command. series of one or more blanks, comma, comma. consecutive. or embedded commas,. in. series of blanks.. a. without. an. intervening. nonblank character,. indicate a missing element in a command string (e.g., "X,,Y"). A command string with one fewer than the permitted number of elements is rightmost treated as if the element is missing (e.g.r if typically then the rightmost element three elements are permitted, is regarded The exception is when the omitted element as missing from "X,Y"). name) have been a (or should data block name program record type immediately following a data item or record type name (e.g., with the CRS command). In this case, the data block name is assumed to be the a"s same the record type or data item name (e.g., is a data item name, then "X,Z" is equivalent to "X,Z,Z").. if. Z. command string there are no All elements are missingsomefromDMLa commands, ifpermissible quotes. For is for a command command string to be the entire it string or 'missing (e.g., FE'S). Some DML commands have no command string (e.g~ DBCLS) elements in the an argument in .. Command. Descriptions. As each DML command is described in the following chapters, examples of the four different categories of command usage are Even within a category, provided. the exact syntax for using a *. 0. host languages do not use double quotes (""). by a host language is described in convention employed specific manual. Some. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. The. its. exact system 7.

(19) MDBS. DMS. MANUAL. - II:. BACKGROUND. MDBS. -. DMS. MANUAL. command. may differ slightly from one host language to another. To repeat, the 4pprQptiat£ áYátéw áHqgi£ig wanml ahQula Kq cQn,ajjlkQg £ql The mnemonic, the exact §YjjtÁx L£AjjjL£g Ky a gjj¿qjj jjQSt l@Dgjj4ge. arguments, currency indicators used, currency indicators changed, and impact on the data base for each dml command are all independent of the host language used. All of these factors are described in subsequent Thus the logic employed chapters of the MDBS DMS Manual. the data manipulation language is the same, regardless of the iii using used. languages host. In presenting the DML commands following conventions are used:. in subsequent Chapters,. the. host language variable for the command status itío the name of a data item defined with the DDL k9g the name of a record type defined with the DDL áeF=LL 'M_?, sgt=3 the names of sets áefined with the DDL áLé@ the name of an area defined with the DDL name the klk of a data block (or program record type) whose host name of adata block (or program recordtype) ihlk the language variables provide input to a DML command oklk the name of a data block (or program recordtype) whose host language variables receive output from a DML command CEUI current of run jjnit indicator CQSsqtL gurrent Qwñer of the indicated set CMLáétL current wember of the indicated set CiLLiL gurrent ijser-defined indicator i (lSiS255) example, CU(7) denotes the current record for the for seventh user-defined indicator EQ. I. Although the description. it. a. E.. for a DML command may refer to a data block, understood should that a program record type takes the place of data block for record-oriented host languages. be. Multiuser. Environment. In a multiuser environment, many run units can simultaneously code. They also share the same copy of serially reentrant MDBS.DMS Each has a common page buffer area. share run unit its own programa region, which contains the application program and program buffers. run unit's program buffers are used by MDBS.DMS to manage the specific Each operations pertinent to that run unit. run unit has its own group of currency indicators, which are maintained independently of other run units' currency indicators. and actively lock various record run unit can passively them from being altered and/or read by other occurrences to prevent The rules governing active and passive locking are run units. Also presented Chapter XIV. in that chapter are the DML presented in and commands unlocking and for controlling the for active locking number of times (and the time interval length) that a DML command will re-try to access a previously locked record. A. 8. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. ".

(20) MDBS. DMS. - II:. MANUAL. BACKGROUND. MDBS. -. DMS. MANUAL. is a mechanism that allows an Built-in to the multiuser MDBS.DMS |appiication both binary and n-ary deadlock developer to prevent a unit attempts an access that will create a situations. run If command a deadlock status error to that effect is returned situation, command DML The run unit can use the access. that attempted for the deadlock a " avoid control to structure information in its this situation. F.. Protecting. Data. Base. Consistency against External Factors. base for processing, a run unit opens a data can specify images then in the case, page is the read-only processing. If this buffer region are always identical to their corresponding pages page Thus data base in auxiliary memory). in the data base (i.e., power (e.g., consistency is not damaged by an abnormal interruption of the run unit, which does not allow the run unit to close failure) the data base.. it. When. unit does not open the data base for read-only Since these then the run unit can alter the data base. region, are necessarily buffered through the page buffer alterations to the can happen that a page image in this region is not identical An abnormal interruption of the run corresponding data base page. unit could leave the data base inconsistent since the latest changes to page images in main memory might not have been written to the data When base. to open the data base efforts this occurs, subsequent command a backup 15. a copy of the data base status error of yield must be used in this event or the recovery utility furnished with the RTL form of MDBS can be used to restore the data base. There are two of such a situation. ways to drastically reduce the likelihood a If processing,. run. it. (DBSAVE) One method makes use of a DML command that rewrites changed page images into the data base. This memory flushing command be used wherever and whenever desired in an application can program. when a run unit abnormally terminates, no changes have been made then the data base to the page images in memory since the last flush, is consistent and error 15 will not occur in a subsequent attempt to open the data base for processing.. all. If,. The second method is available with the RTL form of MDBS in single user situations. allows the run unit to specify a page-image via the PIED command. This method of preserving consistency is particularly useful changethe run unit carries out a complex kind of At some moment transaction that can records on several pages. during the execution of a complex transaction, some changed page image may have been rewritten into the data base, while other altered images may An abnormal termination reside in the buffer region. at would data base inconsistent. the data base leave the this point could be restored to its former state, that existed at the start of complex then data base would be consistent and the transaction, that be the interrupted transaction could reinitiated. This is the purpose of the page image. It. file. if. still. If. file.. (C). COPYRIGHT. 1981. Micro Data Base Systems,. Inc.. Rev.. 85A. 9.

(21) t. MDBS. DMS. MANUAL. - II:. BACKGROUND. -. MOBS. DMS. MANUAL. juncture in a run unit, the TRBGN command can be used to When commit a the beginning of a complex transaction. (TRCOM) command the complex invoked, transaction entire is is committed changes made since TRBGN to the data base. was All last (TRABT) invoked incorporated into the data base. are an abort If command made TRCOM, is invoked instead of no changes that were since TRBGN was last invoked are incorporated into the data base. If the unit abnormally terminates after a TRBGN and before a TRABT run or TRCOM, command then a subsequent to open the data base finds the data base in the state that existed at the beginning of the complex With operating systems that do not dynamically allocate transaction. is important to create a page image file of sufficient sizes, file Because size. posting is not meaningful in multiuser page image available situations, only for the single user version of MDBS. isTRCOM TRBGN, TRABT commands are described in Chapter The PIED, and XVI and in the MDBS RTL Manual. At declare. any. it it. The foregoing mechanisms do not help in the Selective RQ11r)a.ck. hardware event of a failure that physically destroys a portion of the data base. In this case the RTL transaction logging and recovery The DML commands are used to restore the data base. for facilities automatic a unit are run transaction logging within utilizing Thé transaction log in the presented in Chapter XVI. file (defined Either, DDL specification) is distinct from the page-image file. both, or neither can be used by a run unit. In the event of AIEL type termination, in the data base (due to abnormal of inconsistency data entry, etc.) the transaction log file hardware failure, incorrect automatically be applied to a data base back-up copy by using the can RTL This recovery can be selective recovery utility (RCV). logged transactions are used to recover. desired, so that only certain Bad transactions data incorrect entry) can be discarded during (e.g., the selective rollback.. if. about the MDBS recovery facilities available details form of MDBS, of including its use for surveillance activities, are presented in the KDBS RTL Manual.. Full. the. RTL. 10. Rev.. 85A. (C). COPYRIGHT. 1981. Micro Data Base Systems,. with users'. Inc..

(22) MDBS. DMS. MOBS. MANUAL. III. a.. DMS. MANUAL. FINDCOMMANDS. Overview. Manipulation t,anguage supports twenty-four find providing an application programmer with many ways to find a Thé principal objective of any find command is to make given record. a record the current the current member of a set, the owner of a set, The found some the of combination or of these. run unit, current is program record becomes one of the records that the application can mirrmt.1v interested in; as soon as a record becomes current, be processed in various ways by other DML commands. The find commands main groups: into four fall TPíe. MDBS. Data. conunands,. it. 1.. Find. a. member. record via find the. some. record set:. that. is related to. a. given. owner. member, first next member,. last member, prior member,a member member member. which. with particular sort key value, with a particular value for some data item, with the same value for a data item or sort key as an already found member.. is first, next, last, or prior depends on the set's order specified in the DDL. If the member order is sorted, members can quickly be found on the basis of their sort key values.. 2.. member member. Find an owner record that is related to record via some set: find the. a. given. member. owner, tirst next owner,. last owner, prior owner, a owner owner owner. with particular sort key value, a with particular value for some data item, the same with value for a data item or sort key as an already found owner.. Which. owner is first, next, last, or prior depends on the the owner order set's owner order specified in the DDL. If be found sorted, owners can quickly is on the basis of their sort key values.. (C). COPYRIGHT. 1981. Micro Data Base Systems,. Inc.. Rev.. 85A. li.

(23) MDBS. DMS. MANUAL. -. III:. FIND. COMMANDS. MDBS. -. DMS. MANUAL. If a record type was declared in the DDL to have a calc key, then any of its records can be found "out Qt the blue," without reference to any set in which the record type MDBS.DMS participates. finds the desired record on the basis of a calc key value furnished by the application IE "duplicate program. calc keys are allowed, then all records with the same calc key value can be fQund.. 3.. The. application prograiu can sequentially find the records in desired area or areas. This refers to the physical sequence of recorcts.. 4.. a. find command returns a command status of zero, then the the command record was found. then the status is 255, If through a find command does not exist in the data record requested The branching and control structure of a host language base. program is typically based quite tieavily on the command status returned by the various find commands used in the program.. If desired. a. security. DDL schema conditions, in a as defined command when a find are specification, automatically enforced is the user of an application a invoked. program perform attempts to If codes, a read access with user's that inconsistent the "find" is command status will result which indicates that the find was not performed.. Data. 0. Corutµnci. B.. Detai18 EiM Ruplicate Record. EREK. Command. based. on. calc Xey. EJ2RK. and Arguments. FDRK,rec,iblk Currency. Indicators. =:. chanqpd:. cru. record having duplicate calc key value. cruc. Description JLE invQkea: ila AQÉ nUí wtm Un cl]rrent Qt same occurrence as Find an the current of run of the record type matches the calc key value unit, and having a calc key value that a is found, held in iblk's variab1e(s). record If such This command becomes the new current of run unit. is valid only the record that is the current of run unit is an occurrence of rec and rec has been ctefined (in the DDL) as having a calc key. The calc key value indicated by iblk must duplicate the calc key status value of the current of run unit, otherwise a command unit is altered). (the of run results current not error :. = jj=. u. it. if. 12. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. '. ".

(24) MDBS. DMS. FIND. - III:. MANUAL. COMMANDS. MDBS. -. DMS. MANUAL. of FRK, followed by repeated use of FDRK, will find all records of a given record type having the same calc key value. an FDRR The order in which these are found is not guaranteed. If when of a command there are no more duplicatesbecomes is given calc key value, then the current of run unit particular does not have read a user command status is 255. and the null If access to all data items that form the calc key, then a command status error is returned. khe currmt Qt jjñit is FRK. null jÚj£jj EDEE is irlyQkeg: fork tjjlj has exactly the same effect as. Use. If. Examples. of. Command. Usage. block/direct block/indirect record/direct. ED. ... ... ... recorá/indirect.... ED ED ED. = FDRK = DMS = FDRK = DMSD. Eind. EU Commaná. ("rec,iblk"). ("FDRK,rec,iblk") ("rec", iblk) ("FDRK,rec",. Eirst. iblk). =. Member. and Arguments. FFM,set-l Currency. Indicators. IISM:. Chajjgeg:. CO(set-l). member CM(set-l)c first <——first member. CRU. (set-l) (set-l). Description. member connected to the current owner of set—l becomes first member of set-l and the current of the run unit. the current Which member is depends on the set-l member order, as first DDL. owner of set-l has no specified with thecommand If the current member, 255, the then the current of run unit status is becomes null, and the current member of set—l is null. If a user does not have read access to set-l, then a command status. The. error. is returned.. Examples. of. Command. Usage. block/direct block/indirect record/direct. ED. ... ... ... record/indirect.... (C). COPYRIGHT. 1981. Micro. ED ED ED. = = = =. FEM dms. ffm DMS. Data. ("set-l") ("set-l"). ("FFM,set-l") ("FFM,set-l"). Base Systems,. Inc.. 13. ".

(25) MDBS. DKS. MANUAL. - III:. EEQ. Eind. Command. FIND. Eirst. COMMANDS. MDBS. -. DMS. MANUAL. Qwner. EEQ. and Arguments. FFO,set-l Indicatprs. Currency u§£g:. ChaAgeg:. CM(set-l). CO(set-l)<——£irst. c——first. CRU. Description The. owner owner. (set-l) (set-l). first. owner connected to the current member of set—l becomes owner of set—l and the current of the run unit. Which depends owner on the owner order, as is member has no DDL. with the the of current specified owner, then the command status is255, the current of run unit is and the current owner of set-l is null. a user does not null, have read access then a command status to is. the current. first. of. Command. ED. ... ... ... record/indirect... Eiñd. Command. ED ED ED. = = = =. FFO OMS FFO OMS. ("set-l") ("set-l"). ("FFO,set-l") ("FFO,set-l"). Eirst Sequential record. EES. and Arguments. FFS,area Currency. error. Usage. block/direct block/indirect record/áirect. EES. set-l. If. set-l,. returned.. Examples. set-l. If. (the area argument. is optional). Indicators. UáC9:. ch@ng£g:. none. first. cru(. record in area. Description The record that is physically first within the indicated area becomes the current of run unit. I: the indicated area has no records, then current of run unit becomes null and the command status is 255. When the area argument is omitted, FFS operates on the main area and then on all subsequent areas until a record main have data recordsA may no the found area (i.e., is E. allows a user with any access code to find the physically record of an area regardless of the access codes of that first However, the user will be unable to record's record type. FFS. 14. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc..

(26) MDBS. FIND. - III:. MANUAL. DMS. COMMANDS. MDBS. -. DMS. MANUAL. retrieve data from the found record or modify its data unless the user's access authorization permits read or write access to occurrences oil the record type. Examples. of. Command. block/direct block/indirect recorá/direct. Usage ED. ... ... .... ED. record/indirect.... ED ED. = = = =. Eind. ELM. Command. ("area") ("FFS,area") ("area") ("FFS,area"). FFS DMS FPS DMS. Last. or or or or. ED ED ED ED. = = = =. FFS DMS FFS DMS. ") ("FE'S") ") (" ("FFS"). (". EIM. Member. and Arguments. FLM,set-l Indicators. Currency. CO(set-l). tlsé9:. ChgRgQd:. CM(set-l) CRU. (. last. member. last member. <. (set-l) (set-l). Description The. last member connected to the current owner of set-l becomes the current member of set-l and the current of the run unit. which member is last depends on the set-l member order, as with the DDL. the current owner of set-l has no specified member, then the command status is 255, the current of run unit a becomes null and the current member of set—l becomes null. If does have command a read access to set-l, then status not user error is returned.. If. Examples. of. Command. Usage. block/direct block/indirect record/direct. ... ... ... record/indirect.... ED ED ED ED. = = = =. FLM DMS FLM DMS. Eirid. ELQ. Command. ("set-l") ("set-l"). ("FLM,set-l") ("FLM,set-l"). Last Qwner. ELQ. and Arguments. FLO,set-l Currency. Indicators. Ué9: (C). COPYRIGHT. CM(set-l) 1981. Micro. Cbanged:. CO(set-lA——last. CRU. Data. Base Systems,. <———last. Inc.. owner owner. (set-l) (set-l) 15.

(27) MDBS. MANUAL. DMS. - III:. FIND. COMMANDS. MDBS. -. DMS. MANUAL. Description The. last owner connected to the current member of set—l becomes the current owner of set—l and the current of the run unit. which owner is last depends on the set-l owner order, as member has with the the of no current ddl. specified If set-l owner, then the command status is 255, the current of run unit becomes null, and the current owner of set-l becomes null. If a user does not have read access to set-l, then a command status error is returned. of. Examples. Command. Usage. block/áirect block/indirect record/direct. ED. ... ... ... record/ináirect... Eind. MI Command. ED ED ED. = FLO = DMS = FLO = DMS. Member. ("set-l") ("set-l"). ("FLO,set-l") ("FLO,set-l"). based. on data. MI. Item. and Arguments. FMI,item,set-l,iblk Currency. Indicators CO(set-1). tl§eg:. ch!angQg:. CM(set-l). first. having. CRU. member(set-l) data item value. Description. The member record connected to the current owner of set-l, and having a value for itm that matches the value of becomes the current member of set—l. also becomes the current of run unit. Iii there are two or more member records for the current owner of set-l, all having the iblk value for itin, which depends on the set-l member order. The command FNMI one is can be used to find the next member having the same ib1k value. first. iblk,. It. first. for itm.. host languagevariableof iblkmust be consistent in size and type with the itm data item (as specified in the DDL). If the value of iblk's host language variable does not match the itm value of any member record connected to the current owner of set— then the command status is 255, the current member of set—l I, becomes becomes null, and the current of runa unit does null. A command status error is returned have read not user access to both itm and set-l. The. if. 16. (C). COPYRIGHT. 1981. Micro. Data. Base Systems,. Inc.. ".

(28) MDBS. DMS. Examples. Command. of. COMMANDS. MDBS. -. DMS. MANUAL. Usage ED. block/direct block/indirect recorá/direct. ... ... ... record/indirect... Eind. Command. FIND. - III:. MANUAL. = = = =. ED ED ED. FMI DMS FMI DMSD. ("itm,set-l,iblk") ("FMI,itm,set-l,iblk") ("itm,set-l",iblk) ("FMI,itm,set-l",iblk). based. Member. on. ". EMSK. Sort Key. and Arguments. FMSK,set-l,iblk Currency. Indicators Cbanged:. CO(set-l). QSé9:. CM(set-l). first. ". CRU. having. Description. member. (set-l). sort key value. member record that has the sort key value of iblk first connected to the current owner of set—l becomes that is member of set—l. also becomes the current of the current It a sorted member order. have must unit. Set-l The. member records for the current key value, the one that is. several If same sort. sort-clause. and. the run. owner of set-l have the depends on the DDL member order (either. first. the set-l specification for The IMMATERIAL). host language. variable(s) of or key contain there are the desired value. sort iblk If key value the items key, the data sort sort for set-l multiple must be for iblk consistent with the sequence, types and sizes of RECORD-TYPE the data items in the DDL sort key specification. If the key, then is part of the name of the desired record type sort must appear as part of the iblk sort key value; the host language variable holding the record type name must be consistent with a string data item of 8 bytes in size.. LIFO,. FIFO, must. current owner If thematches the sort value. of the set-l has no member whose sort key key value of iblk, then the command status whose 255. The member sort key value immediately follows the is becomes key the current member of set-l, as well value iblk sort The exceptions are when the current as the current of run unit. owner of set-l has no members or when iblk's sort key value is greater than the sort key value of the last member of set—l's current owner. In these cases, the current member of set—l becomes null and the current of run unit becomes null. command access to key.. A. (C). COPYRIGHT. status error. set-l. 1981. and. Micro. all. isdatareturned. Data. if. a. items that. Base Systems,. does not have read user make up the member sort. Inc.. 17.

(29) MDBS. DMS. Examples. MANUAL. of. - III:. Command. COMMANDS. MDBS. -. DMS. MANUAL. Usage. block/direct block/indirect record/direct. ED. ... ... ... record/indirect.... = = = =. ED ED ED. ("set-1,iblk") ("FMSK,set-l,iblk") ("set-l",iblk). FMSK DMS FMSK DMSD. Eind. ENM. Command. FIND. ". ("FMSK,set-l",iblk). Next. Member. =. and Arguments. FNM,set-1. Indicators. Currency Yáé9:. CO(set-l) CM(set-l). chang£g:. CM(set-l)<——next member(set-l) CRU <µ——ñext member(set-l). Description the. ID£¡Dbqt oE set=l is ñQt null wheri ENÉI is inyQk£sj: gjjrr£nt member record (connected to the current owner of set-l) member of set-l becomes the new current the current following which becomes the current of run unit. member of set—l. also member record is Itlogically next depends member on the set-l order, as specified with the ddl. If the current member of set-l current owner of set-l, then FNM is the last member for the When cannot find a next member. there is no next member for the command of the owner status is 255, the current current set-l, member of set-l becomes null, and the current of run unit becomes A conunand status error is returned if a user does not have null. read. If The. next. access. to set—l.. tjjQ current If has exactly the Examples. of. Command. IDQIDkQK same. is null. when enei. FFM.. is. injLQkeg:. fnm. Base Systems,. Inc.. Usage. block/áirect block/indirect record/direct. ED. ... ... ... record/ináirect.... 18. Qt set=1 effect as. (C). ED ED ED. = = = =. FNM DMS FNM DMS. COPYRIGHT. ("set-l") ("FNM,set-l") ("set-l"). ("FNM,set-1"). 1981. Micro. Data.

(30) MDBS. DMS. - III:. MANUAL. FIND. COMMANDS. MDBS. -. DMS. MANUAL. E=. Eind Bext Member based on data 1tem Command. and Arguments. FNMI,itm,set-l,iblk Currency. Indicators m~. sI=a:. CO(set-l). charlqed:. CM(set-1). member(set-l) CM(set-l)<i__next CRU with item value. Description i.ñvoPeck LE the curre.rlt .µleFtjber QÉ smt-1 1& iuüj when The next member record connected to the current owner of set-l, and the value of iblk, having a value for itm that matches becomes the current member of set-l. It also becomes the current The host language of iblk must be of run unit. variable consistent in size and type with the itm data item (as specified in the DDL). If there are two or more member records following the current member of set-l, all having the iblk value for itm, which one is next depends on the set-l member order. If such a record does not exist, the command status is 255, the current member of set-l becomes null, and the current of run unit becomes does not have read access to both itm and set—l, null. If a userstatus then a command error is returned. As in\Tokea: IE Ehe c|lrrent menjber "mt-l túLl JÚléll FNMI member has exactly the same effect as FMI. The record first connected and having a value for to the current owner of set—l, itm that matches the value of iblk, becomes the current member of :. :. =. =1 u. u. GLÉ. set-l.. Examples. of. Command. Usage. block/direct. block/indirect ... ... record/direct ... reeord/indirect.... FNMY. ED. ED ED ED. = = = =. FNMI DMS FNMI DMSD. ("itm,set-l,iblk") ("itm,set-1",iblk). ("FNMI,itm,set-l,iblk") ("FNMI,itm,set-l",iblk). EiM Bext MeInber based on Sort Key. Command. FNMqK. and Arguments. FNMSK,set-l,iblk Currency. Indicators. Used:. CO(set-1). cha.nqe{í:. CM(set-l) (C). COPYRIGHT. 1981. Micro. CM(set-l). CRU. Data. Base Systems,. <. Inc.. 6ext. member. (set-l) having Sort key value Rev.. 85A. 19.

(31) X. MDBS. OMS. MANUAL. - III:. FIND. COMMANDS. WJBS. -. DMS. MANUAL. Description The. next member record (after the current member) that has the sort key value OE iblk and that is connected to the current owner of set-l becomes the current member oE set-l. It also becomes the current of the run unit. Set-l must have a sorted member order. has no current member, then FNMSK behaves just If 8et-l member records for the current owner of set-l If several same sort key value, the one that next depends on. is specification for the set-l member IMMATERIAL). Tlíe language. as fmsk. have the. the DDL sort-clause order (either LIFO, FIFO, host variable(s) of or the desired sort key value. there are iblk must datacontain If items for the set-l sort key, multiple the sort key value be consistent with the sequence, types and sizes of for iblk must DDL RECORD-TYPE items the data in the sort key specification. If then the name key, desired record type the of is part of the sort must appear as part of the iblk sort key value; the host language variable holding the record type name must be consistent with a string data item of 8 bytes in SiZee the. IE. the of the set-l has no member (after current sort key value matches the sort key value The next member of iblk, the command status is 255. member becomes immediately following the current the current The member of of run unit. as well as the current set-l, has when members no the current owner of set-l exceptions are or when iblk's sort key value is greater than the sort key value of the last member of set-l's current owner. the In these cases, current member of set-l becomes null and the current of run unit current. member) then. becomes. A. owner whose. null.. a user does not have status error is returned make and data that up the member items to set-l all. if. command. access key. Examples. Qt. Command. sort. Usage. block/direct. ... block/indirect ... record/direct ... record/indirect.... ED ED ED ED. = = = =. FNMSK OMS FNMSK DMSD. ("set-l,iblk") ("set-l",iblk). ("FNMSK,set-l,iblk") ("FNMSK,set-l",iblk). EiM Next Qwner. ENQ Command. read. ENQ. and Arguments. FNO,set-l Currency jjs,e,d,:. Indicators chanqeq:. CM(set-1). CO(set-l) 20. CO(set-l)<. CRU. (C). COPYRIGHT. 1981. Micro. next owner(set-1) next owner(set-l). ( Data. Base Systems,. Inc.. -.

(32) MDBS. DMS. FIND. - III:. MANUAL. COMMANDS. MDBS. -. DMS. MANUAL. Description Invokea: 1& XE the current owner 9É ff't-i is ñQt Áüáí whm ENQ member (connected of set-l) The to the current next owner record the following current owner of set-l becomes the new current also becomes the current of run unit. Which owner of set-l. It record is logically next depends on the set-l owner order, owner the current owner of set-l is the as specified with the DDL. If member of set-l, then FNO cannot find the current last owner for When a next owner. there is no next owner for the current member command status is 255, the current owner of set-lA of set-l, the the and becomes current of run unit becomes null. null, read command does not have a user status error is returned access to set~l. .. if. the cuFrent QYner Qt rM"1 1& has exactly the same effect as FFO. :. If. Examples. of. Command. JCL9ÁJ. jÚLéjll. u. ENQ. fno. in\Topea:. Usage. block/direct block/indirect record/direct. ... ... ... record/indirect.... ED ED ED ED. = FNO = DMS = FNO = DMS. ("set-l") ("set-l"). ("FNO,set-l") ("FNO,set-l") .. Eind. ENQI Command. Bext. ,Qwner. based. on data. ENQL. Item. and Arguments. FNOI,itm,set-1,iblk Currency. Indicators. Used:. CM(set-l) CO(set-l). ChanqeQ:. CO(set-l)< CRU. Description. next owner(set-l) with item value. LE : Éhe cl]rrent. owner Q£ fíf't-i la i.n\/okea: Ájjíi Ehm enqi member The next owner record connected of set—l, to the current and a matches having the value of iblk, value for itm that becomes the current owner of set-l. also becomes the current The host language variable of run unit. of iblk must be consistent in size and type with the itm data item (as specified in the DDL). there are two or more owner records following the current owner of set-l, all having the iblk value for itju, such a which one is next depends on the set-l owner order. record does not exist, the command status is 255, the current and the current of run unit becomes owner of set-l becomes null, a does have read access to both itm and set-l, user not null. then a command status error is returned.. u=. It. If. If. If. (C). COPYRIGHT. 1981. Micro Data Base Systems,. Inc.. Rev.. 85A. 21.

(33) MDBS. DMS. JL£. MANUAL. - III:. FIND. m. COMMANDS. MDBS. -. u. OMS. MANUAL. c11rrent c)wner StE símT-1 in\/nked: fnoi ñjúj U&ii has The exactly the same effect as FOl. owner record connected to the current member of set-l, and having a value for matches itm that the value of iblk, becomes the current owner of. u first. set-l. Examples. Command. of. Usage. block/direct. biock/indirect ... ... record/direct record/indirect. .... ... ED ED ED ED. = = = =. ("itm,set-l,iblk") itm,set-l,iblk") FNOI ("itm,set-l",iblk) DMS ("FNOI, itm,set-l",ib1k) FNOI. DMS. ("FNOI,. Eind Next Qwner based on Sort Key. pNnqr Command. pjqcwp. and Arguments. fnosk, Currency. set-l,iblk. Indicators. ILs,e.d,:. CO. (set-l). cha.rlqpc1:. CM(set-l). co. (set-l). CRU. <. íiext owner (set-l) having sort key value'. Description The next owner record (after the current owner) that has the sort key value of iblk and that is connected to the current member of the current owner of set-l. also becomes the set-l becomes It have a the must run unit. sorted owner order. Set-l current of has no current owner, then FNOSK behaves just as fosk. If set-l several owner records for the current member of set-l have the If same sort key value, the one that is next depends on the DDL. sort-clause specification for the set-l owner order (either LIFO, IMMATERIAL) The host language variable (S) of iblk must or . contain the desired sort key value. are multiple data If there items for the set-l sort key, the sort key value for iblk must be consistent with the sequence, types and sizes of the data items RECORD-TYPE in the DDL sort key specification. is part of the If sort key, then the name of the desired record type must appear as variable part of the íblk sort key value; the host language holding the record type name must be consistent with a string data item of 8 bytes in size. FIFO,. If the current. member of the set-l has cur rent no owner (after the owner) whose sort key value matches the sort key value of status is 255. The next owner immediately ibik, then the command member becomes the current owner of set-l, following the current Tite exceptions are when the as well as the current of run unit.. 22. (C). COPYRIGHT. 1981. Micro Data Base Systems,. Inc..