MDBS RECOVERY & TRANSACTION LOGGING REFERENCE MANUAL

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(1)MDBS RECOVERY & TRANSACTION LOGGING REFERENCE MANUAL. The. MDBS. RTL MANUAL. Version. Micro. Data P.. Lafayette,. Base O.. 3.08. Systems,. Box. Inc.. 248. Indiana. 47902. USA. Telex:. (312). 209147. ISE. UR. (in Illinois). 303-6300. December. 1985. Copyright Notice This entire. employees . Inc . , and agreement. (C). and is provided for the use of the customer the customer ' g entire contents have been copyrighted by Micro Data Base Systems, reproduction by any weans is prohibited except as permitted in a written with Yicro Data Base Systems, Inc. manual. The. COPYRIGHT 1981,1982. Yicro. Data. Base. Systems,. Inc.. Rev.. 85A. 3251316.

(2) + Any programming. RPTF'P"F",. endeavor. VERSIONS,. AND. of the magnitude evolve over time. necessarily continue to Base Systems, provide vows Inc., to its version For a nominal handling fee.. A WARNING. of the MDBS software will Realizing this, Micro Data users with updates to this. versions of !áDBS software will be considered as separate products. bona fide owners oí previous versions are generally entitled a preferential to rate structure.. New. However,. Finally,. each copy There are. of our software is·persona1ized to identify the sorne licensee. of several levels of this personalization, which involve encryption methods guaranteed to be combinatorially to decypher. Our products have been produced with a very difficult to say nothinq of the substantial investment of capital and labor, base management of involvement area by our in the data years prior concerned we about any Accordingly, principals. are seriously unauthorized copying of our products and will take any and all available legal action against íílegaí copying or distribution of our products.. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc..

(3) MDBS. RTL. MDBS. MANUAL. MANUAL. RTL. Table of Contents CHAPTER A.. I.. OVERVIEW. Introáuction. RTL. B.. CHAPTER. II.. PAGE. A.. Overview.. El.. Command. C. Example. .. CHAPTER III.. Overview.. C.. Using. Command. CHAPTER. V.. CHAPTER. VI.. COPYRIGAT. .. . .. . .. .. .. .. . .. .. . .. . .. .. .. .. . .. .. .. .. IMAGE POSTING. . .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. .. . . .. .. . . . .. .. .. .. .. .. .. .. .. .. . .. 2. 3 3. .. .. .. Details .. .. .. .. . . .. .. .. .. .. .. .. .. .. .. . . .. . . .. TRANSACTION LOGGING. a. B.. CHAPTER IV.. (C). Commands.. .. 2= l l. .. .. .. . .. .. .. .. .. Details. RCV. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. DMS. ERRORS COMMAND. 1981,1982. Micro. .. .. .. .. .. STATUS. .. .. .. .. . . .. .. .. .. .. .. .. .. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . . .. .. .. .. .. .. . . .. . . .. . . .. TRANSACTION LOG FILE FORMAT RCV. .. .. . . .. . . .. .. .. .. MESSAGES. Data Base Systems,. Inc.. .. 3 6. .. 7 7 7 10. 15. 17. 19. i.

(4) MDBS. RTL. MDBS. MANUAL. I. A.. RTL. MANUAL. 'OVERVIEW. Introduction. component of a data base management system is a facility such from various catastrophic happenings as media human RTL form of MDBS has The system or error. failure, failure, through designed been its to provide special recovery capabilities RTL form Tlie image posting features. transaction logging and page consists of substantially modified data base control system, including the a special group of DML commands for controlling nature of image and posting that is desired during the page transaction logging the RTL execution of an application program. In some environments, OF MDBS stanáard form the than may a require larger page buffer form. Also supplied with the RTL form of mdbs is an interactive A. for. vital. recovering. recovery. III utility called. RCV.. transaction has occurred whenever the data base contents are RTL automatically changing, modified (creating, or deleting data). made data base logs all transactions on a data base since the last when a media failure occurs, data base information on disk back-up. is destroyed. when this happens, RCV can be executed to automatically apply all logged transactions to the back-up copy of the data base. This restores the data base to a point close to the last completed transaction before the media failure occurred. A. system interruptiorü power occurs, failure (e.g., in the main memory buffers may be destroyed before the data base is properly closed. This means that the data base may bu data base pages involved in a complex inconsistent, since some-revised of transactions may not yet have been flushed out to disk at sequence the the point of failure, while other revised pages involved in RCV" complex transaction sequence have already been written to disk. However, can be used to restore the data base to a consistent state. a transaction then was the in that log file buffer at failure time, a transaction is lost. prior to invoking RCV it is prudent to make back-up copy of the back-up copy of the data base. This can be time consuming Thus RTL provides an alternative for large data bases. defense against many system failures by allowing page image posting. This means that all pages revised during a complex transaction sequence are committed to disk only when that transaction is complete. System of a complex transaction will not result failure in the midst Only data base the interrupted transaction has been inconsistency. in when data base re-opened. Page image the is posting is not lost meaningful in multiuser processing situations, since all users share the same page buffer. when. a. information. if. when. human. error occurs the data base has been changed in an the standpoints of security and feasibility a data For instance, manner. but erroneous, entry restrictions), may have entered person transactions that were later discovered to be invalid. is important to be able to roll back In such a situation data base, This the deleting the erroneous transactions. effectively RCV, a data accomplished base which selective restoration of is with allows the transaction log to be scanned to identify the erroneous authorized. (from. it. (C). COPYRIGHT'. 1981,1982. Micro. Data. Base Systems,. Inc.. Rev.. 85A. 1. '.

(5) MDBS. RTL. MANUAL. - I.. OVERVIEW. MOBS. -. RTL. MANUAL. RCV is then used to transactions. selectively apply only the valid transactions on the log file to the data base back-up, with the result that the effects of invalid transactions have been eliminated from the. data B.. base.. RTL. Commands. form of !4DBS supports all of the DML commands that form. are normally provided with the standard offers In addition, seven other D!4L commands that are specifically related to recovery. Invokinq a recovery command follows the same conventions as invoking The DblL recovery commands any other DML command. fall into two The. III. RTL. it. groups:. l). those that deal transactions. image. posting of complex. file. TRBGN TRCOFI TRABT. those. page. declaration page image begin postinq a complex transaction sequence the posted transaction sequence is committed to the data base abott the complex transaction sequence. PIFD. 2). with. that deal with the loqqing of transactions TR!3GN TRCOI4. specify an alternative log file sequence start logging a complex transactiontransaction end the logging of a complex. LGFLSá LGMSG. sequence flush the lQg buffer to the write a message to the log. LGFILE. log. file. file. When thus a log file must using RTL, all transactions are logged; on-line, preferably on some device other than the one(s) containing RTL The use of a paqe image is optional. the data base. file LGFLSH LGbíSG Eor ID6IL commands other than and are not available when IDF1L is configured with RTL (rather than Howevet, processing. DMS), automatic transaction loqging of all IDML transactions occucs. The IDI4L user can specify the log file name on the operating system command line, as described in the appropriate system specific manual.. be. Chapter describes describes page image posting. III II RCV The log and logging the the utilization of transaction utility. The chapter explains in is presented Chapter IV. final file format the error messages that can be issued by the RCV recovery utility. Chapter. 2. Rev.. BSA. (C). COPYRIGHT. 1981,1982. Micro. Data. Base Systems,. Inc..

(6) µDBS. RTL. MDBS. MANUáL. RTL. MANUAL. II.PAGE-IMAGEPOSTING A.. Overview. Page-linage of posting may be considered to form a line such as defense against data base inconsistency due to system failures The transaction logging commands provide the power interruption. against failures of many kinds, includinq power ultimate defense and erroneous (although authorized) failures, hardware malfunctions, Page-image data mocíification. posting can optionally' be used by an application program.. first. to specify Fosting allows the application develoeer of a complex transacticn (with the TREGN sequence command). The data base changes caused by the transaction sequence command commit the base the data are not incorporated into until A (TRCQM) TRCOM. DBCLS performs an automatic is invoked. Note that (TRABT) by be sequence can aborted invoking the abort transaction An abnormal termination command. of the program in the miást of a complex transaction sequence will not leave the data base When data base is re-QFenea, the inconsistent. it is consistent. It up the is current point of the last invocation of TRBGN before the to interruption. Page-image. the beginning. page-image preservation file is used by MDBS.DMS to provide this automatic recovery capability. The page-image file must bea declared with the PIED command ftÁÁjt to opening the data base. If page-image File of insufficient size is used, then the data base cQ\jj¿ become sequence inconsistent event, a a transaction is abnormally command interrupted. In this status error to that effect is returned when an attempt is made to re-open the data base. The log of transactions can be used to recover from such a situation (see A. if. Chapter. III).. The four commands used to control page-image posting within an of application program are described in the next section. Section shows example when program page-image an chapter flow using this posting. C. B.. Command. Details. EIEñ. 2age-Imaqe. Command. Elle Reclaration. EIER. and Arguments. PIFD,iblk Currency. Indicators. USM:. (C). COPYRIGHT. none. 1981,1982. chqng£jj:. none. Micro'Oata Base Systems,. Inc.. Rev.. 83A. 3.

(7) MDBS. RTL. MANUAL. -. II.. PAGE. IMAGE. POSTING. -. MDBS. RTL. MANUAL. oescriptimn. indicated by iblk's host language fully qualified file name, a be variable, is declared to image paqe image preservation file for in page use by MDBS.DNIS posting. If posting is áesireá, command be must invoked pricn to use of the TREIGN, TRCOM, this The host language variable must be and TRABT commands. The size (in bytes) is consistent with a string data item. operating system dependent and is documented in the correspondinq system IF EIEQ ia inyQk2g-L specific manual. openpd. it wjj§c áEE9:áK hefo.re 9b:é SA9: á Kass. The. i§. :. of Command block/Girect block/indirect recorá/direct record/indirect. Examples. Usage ED. ... ... ... .... = = = =. ED ED ED. ("iblk"). PIFD DNJS. E'IFD DMSD. ("PIFD,ib1k") (iblk) ("PIFD",iblk). TBansaction. =ART Command. and Arguments (no arguments). TRABT. Currency. ,áEoMF. Indicators. 9aaM:. chanqe(j:. none. currency indicators. most. Description Posting Effects (occur only if This command aborts a complex. <——null. has been invoked): transaction sequence that was TRBGN be aborted the command. by cannot transaction initiated has committed (with the TRCOM command). after command already been NCI invokes This internally to ensure that no inconsistent currency indicators will be present. E?IFD A. it. Logging Effects: TRA2T may be invoked only the transaction sequence RCV recovery processor. Examples. oÍl. Command. block/úúirect block/ináirect recorci/direct record/índirect. ED. ... ... ... .... = = = =. ED. invoked, in which case will be ignored by the. ED ED. OMS. ("TRABT") ). (. TRABT OMS. ). ("TRABT") EeCíiE. r=gN. and Arguments. TRBGN. Currency. aborted. (. TRABT. TEansaction. Command. has been. Usage. KREGN. (no argument). Indicators. timSN 4. PIFD if that is. chanqed:. none (C). COPYRIGHT. none. 1981,1982. Micro. Data Base Systems,. Inc..

(8) MDBS. RTL. MDBS. MANUAL. RTL. MáNUAL. DescriEtion Posting Effects (occur ·only if PIFD has been invoked) : This command denotes the beginning of a complex transaction involving the use oÍl several DML commands. The chanCes sequence, cause in the data base do not become that these DML commands TRCÓM TRCOM the command is invoked. permanent commits until TRABT command changes base. The aborts a these to the data complex After TRCOM or TRABT has been invoked, transaction. TRBGN must be re-invoked to transaction. initiate another complex TRBGN a TRÁBT is re-invoked without having or TRCONI issued If command command, a status error is issued and the re—invocation of TRBGN is ignored by MDBS.DMS. L,ogging Effects: When this command complex sequence of. is invoked, indicates the beginning of a Although transactions. all transactions are RCV automatically logqed, ignore any that transactions will TRBGN unless-a subsequent TRCOM command is encountered. follow The TRBGN and TRCOM commands are used in tandem to ensure that a complex not of completed) or none sequence either is (if Form part oF a complex sequence, are useá all which the transactions, by RCV during recovery. Examples of Command Usage block/direct block/indirect record/direct recorá/indirect.. it. ED. . . . . . . .. ED. .. ... TRCQM. ED ED. -. Command. (. TRBGN. ("TRBGN"). OMS. (. TRBGN OMS. ). ). ("TRBGN"). TEansaction. CQL4mit. TRCQM. and Arguments. TRCC)M. Currency. = = = =. (no argume?ts). Indicators. UM:. none. rhñnq?1i:. Description Posting Effects. none. PIED (occur only has been invoked) : This command commits a complex transaction, that was initiated by the TRBGN command, to the data base. has the added effect of clearinq the contents of the page-image declared with the PIFD command.. if. It. file. Logging. Effects: This command indicates the end of a complex sequence of Any transactions transactions. loqged since the last TRBGN command by the RCV was invoked can now tie processed utility for data base restoration.. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc.. Rev.. 83A. 5.

(9) MDBS. RTL. Examples. MANUáL. QiÉ. MDBS. Ccimmand. MANUAL. Usage. block/direct block/indirect record/direct record/indirect C.. RTL. ED. ... ... ... .... ED ED. £0. ( ) = TRCOM OMS ("TRCOM") = ) ( = TRCQM OMS ("TRCOM") =. Example. using. The following example page-image posting:. illustrates. a. typical. program. ficjw when. pifd 0 0 0. dbopn e 0 0. ov. (obtain and validate. data. new. from. end user). e 0 O. trbqn 0 0 0. (incorporate. commands). new. data. into data. base. with appropriate. DML. 0 0 0. trcom 0 e ©. (iterate dbcls. to ov,. as. desired). Notice that the page-image betore cpening the data file is declared base. The end user is prompted complex new áata. transaction for sequence is initiated beby TRBGN. sequence of transactions is complex involves related changes tci generally consideredWhen to TRCOM executed, is several records. that make up the all changes data the base. complex transaction sequence are committed the to If the program is interrupted after TRBGN and betore TRCOM is completed, chanCes are not committed to the data base. Even though the data base in cari be reQpened and its contents closed not is this situation, are consistent. A. Áb. if it. it. 6. Rev.. 83A. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc..

(10) MDBS. RTL. MDBS. MANUAL. RTL. MANUAL. IILTRANSACTIONLOGGING a.. Overview OF. Transaction loqqinq allows an application program to make use the log file defined in the DDL specification. The name of the file used For loqginq a program's transactions can be changed with the LGFILE command. Aíl transactions since the last data base back-up are logged onto the log file. The log file is used by the automatically RCV RCV can be used (provided to with MDBS-RTL). back-up an copy of the data automatically re-aFply transactions to old an base, The user has up-to-date data base. thereby recreating which extensive control over transactions are re_applied.. utility. command is used to indicate the start of a complex transactions, for the purpose of transaction loqging. The command TRCOM terminates the complex transaction sequence started by TRBGN. RCV ignore any lc'qqed transactions that occur after an will TRCON! was not reached TRBGN, a subsequent durinq a run unit. Other commands that can be used in conjunction with transaction logging are LGFLSE and LGMSG which flush the loq buffer and insert messaqes file the into lcq file, respectively. The sequence. TRBGN. OE. if. The commands. next section of this chapter describes the five recovery that can be used in conjunction with transaction loqqing· explains how to use the RCV recovery utility to restore the Section data base or for the purpose of user surveillance. C. B.. Details. Command. -. T8ansaction. TEMN Command. aegiN. TREGN. and Arguments (no arcµments). TRE!GN. Currency. LGCPLX. (no arguments). Indicators. g§gg:. none. Description. Logging When. or. Ch4ngggj:. Effects:. this. is invoked, indicates the beginning of a Althouqh transactions. all transactions are automatically loqqed, RCV will ignore any transactions that TRBGN TRCOM command is encountered. unless a subsequent follow The TRBGN and TRCOt4 commands are used in tandem to ensure that complex sequence is not completed) of either all or none which (if aform the transactions, of a complex sequence, are used part by RCV during recovery. complex. (C). COPYRIGHT. command sequence of. none. 1981,1982. it. Micro. Data Base Systems,. Inc.. 7".

(11) MDBS. RTL. MANUáL. TRANSACTION. - III.. LOGGING. MDBS. -. RTL. MANUAL. PIFD has been invoked) : Posting E££ecta (occur only This command denotes the beginning of a complex transaction sequence, involving the use of several DML commands. The changes that these DN!L commands cause in the data base do not become TRCOM permanent the TRCOM command is invoked. commits until The TRABT command aborts a these changes to the data base. complex transaction. After TRCOM or TRABT has been invoked, be TRBGN must re-invoked to initiate another complex transaction. TRBGN re-invoked without having issued a TRÉ\E1T or TRCOM is If a command command, status error is issued and the re-invocation MDBS.DMS. TRBGN ignored by of is. if. of. Examples. Command. block/áirect block/indirect record/áirect record/indirect. Usage ED. ... .. ... .. . .. = = = =. ED ED ED. ... ( ) TRBGN OMS ("TRBGN") ( ) TRBGN OMS ("TRBGN"). Command. ED ED ED ED. = = = =. ( ) LGCPLX Dt4s ("LGCPLX") ) LGCPLX (. DN!S. ("LGCE'LX"). CQEMt. T8ansaction. TRCQM. or or or or. and Arguments. TRCOM. (no arguments). (no arguments). LGENDX. or. Indicators. Currency úáéd:. rhanqpd:. none. none. Description. Logging Effects: This command incjicates the end of a complex sequence or Any transactions logged since the last trbgn transactions. by the RCV command was invoked can now be processed utility for data base restoration.. Posting Effects (occur This command commits a the TRBGN commaná, to clearing the contents PIFD command.. Examples. of. Command. block/direct block/indirect record/direct record/ináirect. 8. Rev.. 83A. (C). PIFD has been invokeci) : complex transaction, that was initiated by has tm aáieá effect Ci£ the data base. declared with the of the paq+image. only. it. It. file. Usaqe. ... ... ... .... ED ED ED. £0. COPYRIGáT. = = = =. TRCOM DN!S. ). ("TRCOM"). TRCOM OMS. (. (. ). ("TRCOM"). 1981,1982. or or or or. Micro. ED. £0 ED ED. = = = =. LGENDX OMS. ). ("LGENDX"). LGENDX OMS. ('. (. ). ("LGENDX"). Oata Base Systems,. Inc..

(12) 9DBS. RTL. MANUAL. -. LOG. UI'TTP Command. LOGGING. TRANSACTION. III.. MDBS. -. MANUAL. T'PFTTF. specification. ELLE. RTL. and Arguments. LGFILE,iblk indicators. Currency. u=d:. ch('ínqpd:. none. none. Description. fully qualified name of a file to which transactions can be logged is specified by iblk's host language variable. This must be consistent with a string data item, whose variable maximum length is operating system dependent (see the appropriate manual system information). size specific for If the file to which transactions are to be logged is the same as the log file specified in the DDL specification, this command need no.t be IE invoked. is invoked, this command must appear before the. The. it. command.. DBOPN. Examples. of. Command. block/áirect block/indirect record/direct record/indirect. Usage ED ED ED ED. .... ... ... .... U'PUH. LoG. Command. ("iblk"). ("LGFILE,ib1k") (iblk) ("LGFILE",ib1k). file. buffer ELuáá. TGW¶¶. and Arguments. LGFLSH. Currency. = LGFILE = DMS = LGFILE = DMSD. (no arguments). Indicators. lláM:. ch('ínqpri:. none. none. Description The buffers holding transactions to be logged are flushed to the LGFLSH is automatically log file when this command is invoked. invoked This is especially useful when an important by DBSAVE. transaction has been processed by the system. It can be written to the log file before the log file buffer is full. Examples. of. Command. block/direct block/indirect record/direct. Usage. .... ... ... record/indirect.... (C). COPYRIGHT. 1981,1982. ED ED ED ED. ( ) = LGFLSH = DMS ("LGFLSH") ( ) = LGFLSH = DMS ("LGFLSH"). Micro. Data. Base Systems,. Inc.. 9.

(13) MDBS. RTL. MANUAL. -. III.. fcMqc. TRANSACTION. Log. Command. File. LOGGING. MDBS. -. MeSsaGe. RTL. MANUAL. TcMqcF. and Arguments. LGMSG,iblk Currency. Indicators. 4:. ch¶nqpc1·. none. none. Description. specified in iblk's host language variable is written This variable must be consistent with a string tile. 90 bytes. Messages written to the log item exceeding data not be listed using the RCV utility program. can file command is especially useful for surveillance. The use of the LGMSG. The message to the log. ExampÍes. OF. Command. block/direct blocklindirect recorcildirect record/indirect. 10. Rev.. 85A. (C). Usage. ... ... ... .... ED ED ED ED. COPYRIGHT. ("iblk"). = LGMSG = DMS ("LGMSG,iblk") = LGMSG = DMSD ("LGMSG",. (iblk). 1981,1982. iblk). Micro. Data. Base Systems,. Inc..

(14) mBs C.. RTL. MANUAL. Using. RCV. -. III.. LOGGING. TRANSACTION. MDBS. -. RTL. MANUAL. to display logged transactions copy of the back-up data base. to to apply these transactions RCV enforces A user all security conditions specified in the DDL.type, cannot display a transaction involving a data item, record set A have read áoes he apply which cannot not user or area to access. transactions to the data base unless he has write access to all data items, record tyoes, sets, and areas involved in the transactions. The. RCV. and. enables. processor. a. user. a. Before. using. RCV,. several precautions should. be. taken:. is you are using RCV, RA= 8Aá£ F\Acr-rTp' If has been This way. lost in somebase your master data base is that the information in your back-up data important. Do not risk losing it during the recovery process.. BACX. it. !12. because means. The RCV processor does not write to the EAcRjlE=ARLAgEILE! transaction log file, but a back-up is cheap insurance.. is executed from the operating system as described in the The disk containing the main data pertinent system specific manual. base area must be on-line. RCV can be invoked with a -tj argument on the command line to explicitly allocate the page buffer region. If this argument is not specified, approximately half of the available The remainder memory is automatically allocated. of available memory is reserved as a non-data base working space (e.g., file control IF the argument is used, has the form -bnnnnn blocks, stack). where nnnnn is the (decimal) number of bytes to be allocated for the page butter region. This number should be at least as large as the Dl.lS "minimum region size" reported by the DDL Z'malyzer, buffer DMS command status error 31 results. otherwise too large a page region is requested, an error message indicating "excessive buffer request" memory is displayed. The remaining memory reserved for nonbase However, data working space is normally sufficient. in rare cases this working space may be insufficient, in various resulting kinds of error conditions and situations where the data base may be left open. In such a case, -b can be used to allocate a smaller page buffer region to allow a larger non-data base working space. RCV. it. If. When. is executed, the RCV banner message appears on the by including a -m console screen. This banner can be suppressed RCV. command used argument in the In any event, the to invoke line user is prompted for the ful-ly qualified file name oÍi the main data base area, user name, and user password. These prompts can be suppressed by including -d, -u, and -p arguments on the command line used to invoke RCV. I: used, the -d should be followed immediately by the main area's tile name, the -u by the user name, and the -p by the password. RCV checks to see whether the user name and password are valid for the indicated data base. RCV. E. (C). COPYRIGHT. l98l,l982. l4icro. Data. Base Systems,. Inc.. Rev.. 85A. 10.1.

(15) MDBS. RTL. If. MANUAL. - III.. TRANSACTION. LOGGING. MDBS. -. RTL. MANUAL. they are. valid, the user is prompted to specify the log file is specified, the data base's default log file (as DDL specifications) The log defined in is assumed. file name inantia RCV be can pre-stored subsequent prompts to responses all separate file. argument or the this file name appears after a RCV command line, then its responses are automatically input in Another reaction to RCV prompts. optional argument is -v which means that RCV will operate in a verbose mode, giving a running commentary a log of its actions as processes file. name.. If. none the. -i. If. it. Once. Eollowinq. log. a menu. Options:. 10.2. Rev.. BSA. has been file options: of. (List, Quit,. (C). COPYRIGHT. designated,. Reset,. Scan,. 1981,1982. a. user. is prompted. with the. Update)?. Micro. Data. Base.. Systems,. Inc..

(16) MDBS. RTL. MANUAL. options is. MDBS. -. RTL. MANUAL. When range. a. RCV. log Elle (S). Scan the. the. LOGGING. selected option is completed the menu of displayed. These options are described below.. of After processing again. l.. TRANSACTION. - III.. this option is selected, the of transactions to be scanned: '. First transaction Last transaction. user is prompted. for. Ill?. #. t Ihighestl?. Transaction numbers are entered as eight hexadecimal digits (i.e., OOOOOQOl through FFFFFFFF). Pressing a carriage return in has the same result as to the first transaction response OOOOOOOl. a Pressing entering carriage return in response to the same has the effect as entering the number of last transaction : the log file. last transaction on #. is. when the transaction presented with: User. range. has been. specified,. the. operator. lalll?. name. This allows the operator to scan only that information which pertains to the specified user. The user name which is entered must be a name which appears in "User Login" transactions. If the default is entered (i.e., the RETURN or enter key is pressed), information pertaining to all user8 within the range is scanned.. In scanning the log file, RCV displays all messages, data opens, data base closes, user logins, and user logouts appearing on the log within the indicated range of The user name associated transaction numbers. with each login is also displayed. base. file. 2. range. List of the log file (L) When this option is selected, the user is prompted for the of transactions to be listed: Ill? First transaction #. Last transaction. Ihighestl?. #. Transaction numbers are entered as eight hexadecimal digits (i.e., OOOOOOOl through FFFFFFFF). Pressing a carriage return in has the same result as to the first transaction response OOOOOOOl. Pressing a entering carriage return in response to the number has the same effect as entering the last transaction number of the last transaction on the log file. #. When. the. is presented User (C). COPYRIGRT. transaction with:. name. range. has been. specified,. the. operator. lalll?. 1981,1982. Micro. Data Base Systems,. Inc.. li.

(17) MDBS. RTL. MANUAL. : III.. TRANSACTION. LOGGING. MDBS. -. RTL. MANUAL. This allows the operator to only that information which pertains to the specified user. The user name which is entered must be a name which appears in "User Login" transactions. If the default is entered (i.e., the RETURN of ENTER key is pressed), information pertaining to all users within the range is. list. listed.. list within the indicated The. option displays. log file all transactions in the The of transaction numbers. data values involved in transactions displayed by this not are command. This command is useful for determininq the starting and ending transactions to be used in recovery processing. oF. Theformat run. unit id. range. outputfrcm transaction. the. lístoption is. number. as. transaction. ... follows: description. number transaction number is a unique eight digit hexadecimal The number a run unit id is that identifies the transaction. assiqned by RTL to a tmn unit; the meaning OF this number is system specific and is generally of interest to the RCV The Eollowinq transaction descriptions can appear for a usec. log file. The. little. Abort Transaction Sequence Appearance TRABT in preceding. recovered.. this message indicates a successful invocation of Any transactions between the source program. "Begin Transaction Sequence" and the abort will not be of. a. Transaction Sequence. Begin. this message indicates that the user has called the Any further transactions for in a source program. be processed by RCV unless an TRCOM this user willa nak user/system loqoff transaction is encountered. transaction or. Appearance. of. command. TRBGN. Commit. Transaction Sequence. This transaction Create. indicates. the. end. of. a. transaction. sequence.. Record. type of the record is listed, followed by the the record Note that the newly created record. identifier ofmember or owner of any sets, several "Insert Record is the auto Set" transactions inay Eollow. in. The. record. Data. Base Closed. if. additional information is listed. Note that for system, this indicates the close of the data base. close is,indicated by a User Logoff.. No. 12. (C). COPYRIGHT. 1981,1982. Micro. a. multi-user run unit. A. Data Base Systems,. Inc..

(18) MDBS. RTL. MANUAL. LOGGING. MDBS. -. RTL. MANUAL. Base Opened. Data. additional. No. TRANSACTION. - III.. information is. listed.. Delete Record The. record. identifier. OF. the. deleted record is. listed.. Insert Record in Set of the set is listed, followed by the identifier of the record which is being added to the set. For certain classes of sets, the identifier of the current owner (member) of the set is displayed, followed by the identifier of the current member. The ,. name. (owner).. Message A. entereá. message. in the transaction. displayed.. file. by the. LGMSG. command. is. put Data in Record The. record type of the record. Put. followed by the record. is displayed,. identifier. Field in Record. The. record type is displayed, followed by the item type. The record identifier of- the record to be stored will also be displayed. Record. Remove. From Set. The name of the Setr the current owner record's the current member's identifier are displayed.. and. identifier. .. Set Members. Remove. The. set. User. and. set. name. and. User. data. base.. identifier. are. displayed.. its current. owner. identifier. are. displayed.. indicates. that. specific. user. has been. a. using. Logout. This transaction the data.base.. (C). owner. Login. This transaction the. its current. Set Owners. Remove. The. name. COPYRIGHT. 1981,1982. indicates that. Micro. Data. a. specific. Base Systems,. user. Inc.. has ended. use. of. 13.

(19) MDBS. RTL. MANUAL. 3.. -. Update. the. III.. TRANSACTION. data. LOGGING. MDBS. -. MANUAL. RTL. (U). base. when this option is selected, the user is prompted for the range of transactions that are to be used for updating the copy oÍl the back-up data base:. First transaction. Last transaction. # #. Ill?. lhighestl?. Transaction numbers are entered as eight hexadecimal digits (i.e., OOOOOOOl through FFFFFFFF). Pressing a carriage return in has the same result as to the first transaction response OOOOOOOl. Pressing a entering carriage return in response to the number has the same effect as entering transaction the last number of the last transaction on the log file. #. the. When. is presented User. transaction with:. name. range. has been. specified,. the. operator. Ialll?. This allows the operator to update using only those transactions in the range that pertain to the specified user. The user name which is entered must be a name which appears in "User Login" the default is entered, transactions pertaining transactions. If the range are used for updating. within users to all The update option automatically applies all log transactions within the indicated range for the indicated user(s) to the copy of the back-up data base.. file. 4.. Reset. the. log. file. (R). the reset option is selected, the user is prompted to that the reset is actually desired. The reset option has the effects OF deleting all information from the indicated log and re-initializing that Extreme caution must be file file. when cowmand, since exercised using this destroys the log The user maywish to make an archival copy of the log before the reset option is used. When. assure. it. file.. file. P. If a data base has been initialized withoutRTL, thatdata base can. and loaded using MDBS DMS When RTL. later be used with and revise any switching to RTL, execute the reset option The necessary that involve transactions. application programs make each must the LGFILE program use of revision that is command, with the name of the that was reset.. first. file. 5.. Quit. (Q). When. this option is selected, the. closed.. 14. ,Control is returned to. (C). COPYRIGHT. 1981,1982. the. data. base and. operating system.. Micro. log. file. Data Base Systems,. are. Inc..

(20) MDBS. RTL. MANUAL. MDBS. IV.. RTL. MANUAL. TRANSACTIONLOGFILEFORMAT. functions are currently defined in the transaction file. desc: is given on the brief iptionThe of the format oF each function follQwinC pages. transacticm file consists of a byte stream in which transactions immediately follow one another (Le., no separatcm The byte of each loCícal disk recotd contains a characters). First hex Á7, except that the last block contains a hex value, indi'catinq an end oí second byte is a checksum such that the sum of The file. all bytes cjfin the record is zero. There is an 'xx' byte header at the Twenty. A. AB. the'file.. beginning. NOE?. O. l. No-op. CR. l. 9+. Create. Qffs?r}. paramer?rj(>Y"p. ?'ín"tMn Vái= Terwth Y?ñnjnq. none. Record. l2-. Run Unit Id 3: Data Length :. 4. S9+. Type. : Run Unit Id 2- 3: Set Type 4- 7: Record Identifier. IMS. 2. 8. Add. Record to Set (System-owned, non Next/prior Set). I. INS. 3. 12. Add. l2-. Record tcj Set (System-Qwned, Next/Prior Set). Recaed. :. 8: Recorá Identifiet : Data Values. : Run Unit Id 3: Set Type 4- 7: Recoui Identifier 8~11: Aíijacent Recorá. Identifier. IMS. IMS. 4. 5. 12. 16. Add. Record to Set (non System-Qwned, non Next/Príor Set). Record to Set (non System-Owned, Next/?rior Set) Add. : Run Unit Id 3: Set TyFe 4- 7: Record IdentiZiec. l2-. Qwner/Member. B-ll:. Identifier. : Run unit Iá 3: Set Type 4- 7: Record Identi£iet. l2-. Qwner/Mentber. B-ll:. Icíentifier. 12-15:. Adjacent. Record. Identifier IMS. 6. 16. Record to Set (non System-Owned, Next/Príor Set). Add. CQPYRIGRT. 1981,1982. Micro. Data. Run. :. IRentifier. Aíijacent '. 3ase. unit Iíi. 2- 3: Set Type B-ll: Cwner/Xember 12-15:. member->owner. (C). 1. Systems,. Recorá. Identifier. Inc.. Rev.. 823. IS.

(21) MDBS. RTL. F'iñ'Tl"m. MANUAL. itu=. - IV. r?nqth. TRANSACTION. LOG. N"nñiN. FILE. FORMAT. -. MOBS RTL. ?ír?n)"!"@r¶(hYrp. MANUAL. QfF¶pt-). ?FC. 7. ll+. Set Fielá in Record. : Run Unit u 3: Data Length 4- S: Item Type 6 : Record Type 7-10: Record Mentífier ll+ : Data. E'UTC. 8. 9+. Set Field in Recorci. l2-. RMS. g. Remove. l2-. 12. l2-. : Run Unit Id 3: Data Lenqth 4 : Record Ty?e S- 8: 2ecorcí Uentifie: 9+ : Data. Member. from Set. :. Run. : Cí. Unit. 3: Set Type 4- 7: Owner rdentiFieF. B-ll:. Member. IdentiZier. RSX. IQ. 8. ASO. li. 8. Remove Cwner. Set. l2-. DRC. 12. 6. Delete. Record. l2-. : S:. (jLI. 13. 5+. User Login. l2-. Cjriit Id Run 4: External : User Name. RemQve Membecs. Set. : Run Unit Id I 2- 3: set TYpe 4- 7: Cwner Identifier : Run Unit u 3: Set Ty?e 4- 7: Member UíentiZier. 5+. :. Unit f¿ Record Mentífíer. Run. Run. (JL(J. 14. 2. User Lciqout. !. :. Run. ljñit Id. ESZQ. 15. 2. ZÁíi Transacticm Sequence. l. :. Run. Unit. Ici. BSEQ. !6. 2. Beqin Transaction. I. :. Run. Unit. ui. :. Sequence 17. ,usg. DBCL. 18. DBQP. 19. AET. 20. 4+. Messaqe. 16. Rev.. 823. 3:. 4+. :. Run Unit LenccU Messaqe Messacce. :. Run. Data. Base. Clased. none. Data. 3ase. Cpened. none. 2. Abort. T: ansacticin. Seq't'ence. (C). C2PYRIGEIT. 1981,!982. u. l2-. l l. l. Micro. Data. fjnit Iá. Unit. Base. u. Systems,. Inc..

(22) MDBS. RTL. MDBS. MANUAL. RTL. MANUAi. V. RCVERRORS. ***. CAN'T. CREATE. specified. The. CAN'T. ***. file. OPEN. specified. The. ***. could. FILE. file. ERROR. DMS. 'name'. FILE. not. be. created.. be. opened.. 'name'. could. not. DETECTED. n. This message is usually caused by the same factors as the UPDATE ERROR FOUND message. Note that "n" corresponds to a data base error number. *** Two. or. IMPROPERLY. transactions transactions.. TRBGN TRCOM. ***. TRANSACTION. WBEDDED. were. SEQUENCE. encountered. without any intervening. TRABT. MEMORY. INSUFFICIENT. not have sufficient memory available to allocate needed The pointers buffers tables. described in the installation information may be altered to increase the memory available.. RCV. does. and. *** An. INVALID. TRANSACTION. TYPE. ENCOUNTERED. invalid. transaction was.encountered This in the transaction file. An due to a damaged transaction end of file is file. may continue. at the error point in the file, and processing. is usually assumed *** I/O An. m'*. ERROR. ON. Input/Output RUN. PILE. 'name' detected. error. was. NOT. FOUND. UNIT ID. on the. specified. file.. multi—user systems, a compact user id is maintained in the transaction file. If a transaction with an invalid or unknown user id Usually this will only is encountered, this message ishasdisplayed. happen a User Login not been encountered for the user, function of which is often the result an improper specification of the first transaction number. For. if. ***. SYSTEM. CLOSE. WITHOUT. PREVIOUS. OPEN. message may come abciut due to a damaged transaction file or due to use of a first transaction specification of a transaction which is not a "system open" transaction.. This. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc.. 17.

(23) MDBS. RTL. 'u'". MANUAL. SYSTEM. -. OPENED. BUT. NOT. V.. RCV. ERRORS. PREVIOUSLY. MDBS. -. RTL. MANUAL. CLOSED. This rather unusual message indicates that two "system open" transactions without an intervening "system close" transaction were encountered. This may indicate a damaged transaction file.. '^*. UPDATE. ERROR. FOUND. This message may indicate several problems. occurs Generally, the data base and transaction file do not correspond (i.e., using a transaction file associated with data base "A" won't work you are applying to data base "B").. it. if. it. m'*. USE. HEX. This message number for a ***. USER. In. a. NOTATION. is generated when the user. RCV. LOGIN. prompt.. NOT. PREVIOUSLY. fails. to enter. a. valid. have two "user login" transactions intervening "user logout" transaction.. 0. USER. without. TABLE. hex. LOGGED. multi-user system, an. encountered. ***. if. been. OVERFLOW. multi-user system, the transaction File may contain transactions Since RCV is initialized a large number of simultaneous users. 20 simultaneous users, this message probably indicates a to handle damaged transaction file. In. a. from. -. 18. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc..

(24) MDBS. RTL. MANUAL. MDBS. RTL. MANUAL. VI.DMSCOMMANDSTATUSMESSAGES There are several command status error messages that are exclusively related to the posting and logging as described in Chapters. II. and. III:. **55**. file. Log. Possible Causes: l. An I/O error 2.. file.also. See. **56**. **55**. error. encountered when. was. Command. I/O. Status Log. file. (in the. 51. not. trying to. MOBS. OMS. open. ttie log. wanual).. **56**. current. Possible Causes: l. The log file is not up-to-date. Loqqing. **57** Possible Causes: An Í/O error l.2. The log file **58**. was may. **57**. inhibited. detected on the log already be open.. Page-image. file. I/O. file. **58**. error. Possible Causes: l. An I/O error read. 2.. See. was encountered when an attempt was made to write to the page-image preservation file. Manual). also Command Status 51 (in the MOBS from. or. **70**. OMS. No. transaction. in proqress. **70**. Possible Causes: attempt was made to abort or commit a transaction l. An sequence without having previously invoked TRBGN. "*71**. Transaction already in proCress. Possible Causes:. l.. (C). TRBGN TRCOM. COPYRIGHT. was invoked twice without between the two TRBGNS.. 1981,1982. Micro. Data. Elase. **71**. having invoked. Systems,. Inc.. Rev.. TRABT. 83A. or. 19. '".

(25) MDBS. RTL. MANUAL. - VI.. OMS. COMMAND. Page-image. **72**. STATUS. MESSAGES. -. MDBS. RTL. MANUAL. **72**. posting not active E. Possible Causes:. l.. TRABT. imaqe". without having previously declared preservation file with pied.. was. invokeá. Page-image. **73**. file. index. Log. -. file. not. page-. **73**. overflow. possible Causes: a transaction sequence was too long. l. 2. More than sixty paCes have been altered transaction sequence. **74**. a. in the course of. a. **74**. present. possible Causes: the RTL fortn of MOBS, the data base was opened without l. Using Processing the log file being present. continues.. 20. Rev.. 83A. (C). COPYRIGHT. 1981,1982. Micro. Data Base Systems,. Inc..

(26) DOCUMENTATION. MDBS. CGMMENT. FGRM. Title:. Document. welcome and appreciate all comments and suggestions that can Use this form to help us to improve our manuals and products.' express your views concerning this manual.. we. Please do not use this form to report system ?roblems or to request materials, etc. System problems should be reported to MDBS by pMne or telex, or in a separate to the letter addressed the Requests technical for support division. attention of published materials should be addressed to the attention of the marketing division. Sender: (posLtIQnj. (name). (telephone). (company) (adGress). (ctty, state, zípÍ COMMENTS:. Areas of comment are general presentation, Format, organization, completeness, a comment applies to a accuracy, etc. clarity, specific page or pages, please cite the page number(s).. If. Continue. on. adáitional. pages,. as needed.. Thank you. for your response..

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