This glossary includes terms and definitions either used or paraphrased from the following sources:
The IBM Dictionary of Computing
The American National Dictionary for Information Systems
The Information Technology Vocabulary, developed by Subcommittee 1, Joint Technical Committee 1, of the International Organization for Standardization and the International Electrotechnical Commission (ISO/IEC JTC1/SC1). Sybase also used definitions from draft international standards, committee drafts, and working papers being developed by ISO/IEC JTC1/SC1.
This glossary uses the following references:
Contrast with refers to a term that has an opposite or different meaning.
Compare with refers to a term that has a similar meaning.
See also refers to terms that have a related meaning.
Words containing these references are highlighted.
The part of the DB2 log where log records are written as they are generated. The active log always contains the most recent log records. The archive log holds older records that no longer fit on the active log. See also Database 2. Contrast with archive log.
The server in the Sybase Client-Server architecture. It manages multiple databases and multiple users, tracks the actual location of data on disks, maintains mapping of logical data description to physical data storage, and maintains data and procedure caches in memory.
An identifying number (often hexadecimal or binary) that describes a location in computer memory where information is stored.
The complete contents of a row after an update or insert. See also image. Contrast with before image.
A predefined functional interface, supplied by an operating system or other licensed program, that allows an application program written in a high-level language to use specific data or functions of the operating system or the licensed program.
Replication Agent for DB2 includes the Replication API, an open API to which application developers can write Replication Extract programs. See also Log Transfer Manager for z/OS, Replication API, and Replication Extract.
The part of the DB2 log that contains log records that no longer fit in the active log. See also Database 2. Contrast with active log.
The process of populating a replicate database using Replication Server commands that prevents client applications from executing transactions against the primary database while the subscription data is unloaded.
The process of granting a user either complete or restricted permission to access an object, resource, or function.
A facility that recognizes the programs authorized to use restricted functions.
The process of populating a replicate database using Replication Server commands. After the replicate database is populated with a copy of the primary data, this command automatically activates your transaction replication subscriptions. Replication Server supports automatic materialization only from primary databases to which it has a connection (through a gateway, if necessary) and that can process SQL.
The complete contents of a row before an update or delete. See also image. Contrast with after image.
A VSAM data set that contains name and status information for DB2 and RBA range specifications for all active and archive log data sets. See also relative byte address and Virtual Storage Access Method.
A transfer method wherein multiple rows of data are inserted into a table in the target database.
A method of initializing subscription data outside the replication system. This is also a process of populating replicate transactions into a remote database management system before receiving distribution of changes from the Replication Server. See also materialization and Replication Server.
A library of routines that is part of Open ClientConnect. Open ClientConnect’s Client-Library comprises a subset of the Open ClientConnect Client-Library routines.
An instruction to DB2 to make permanent the changes requested in a transaction. See also transaction. Contrast with rollback.
A transaction operation used to negate the effects of another operation with a lower origin queue ID in the same transaction. Replication Server reconciles compensatory operations and their counterparts so that neither are applied in the replicate database. See also origin queue ID.
To define to a system the devices, optional features, and programs installed on the system.
An IBM product that provides an environment for building, using, processing, and maintaining databases in the z/OS and VSE environments for online transaction processing (OLTP). See also online transaction processing.
A set of related data tables and other database objects that are organized and presented to serve a specific purpose.
A computer-based system for defining, creating, manipulating, controlling, managing, and using databases. The software for using a database can be part of the database management system, or it can be a stand-alone database system. Contrast with relational database management system.
A relational database management system for the IBM z/OS operating system. See also Multiple Virtual System.
The name of a JCL DD statement (also called “file name”) that identifies one or more input/output data sets. See also data definition statement.
A statement required in an z/OS job to describe an input or output file and associated data sets. See also job control language.
The process of partitioning data to more than one location. Data distribution is distinct from data replication. Distributed data is partitioned among different sites in the distributed system as a single image and is not necessarily replicated data. See also data replication.
A program that isolates applications from storage devices, storage management, and storage device hierarchy management.
The process of copying data to remote locations. The copied (replicated) data is then kept synchronized with the primary data. Data replication is distinct from data distribution. Replicated data is stored copies of data in particular sites throughout a system and is not necessarily distributed data. See also data distribution and transaction replication.
A database management system program that responds to client requests. See also local area network.
A thread from Replication Server into the replicate database used to transfer messages from Replication Server to the replicate data server.
A keyword that identifies the characteristics of stored information on a computer. Some common datatypes are char, int, smallint, date, time, numeric, and float. Different databases support different datatypes.
The process of turning the data contained in operational systems into data that can be used by analysts and management to make business decisions. This typically involves:
Moving the data to new servers, both to avoid overloading operational systems with analysis queries and to take advantage of database engines more efficient for decision support
Transforming, summarizing, and reconciling the data gathered from disparate operational systems into formats more suitable to decision support
A database application characterized by ad hoc queries, reports, calculations, and few data-update transactions.
In contrast to online transaction processing (OLTP), processing that is characterized by fewer, more complex, longer-running transactions from fewer users. Transactions are typically queries only and may reference data from many tables. Database systems designed and tuned for DSS are commonly used to hold Data Warehouse data gathered from operational systems. Contrast with online transaction processing.
A Sybase Open Server application that provides access management for non-Sybase databases, copy management (transfer), and remote systems management. Each DirectConnect consists of a server and one or more service libraries to provide access to a specific data source. DirectConnect replaces the products “MDI Database Gateway” and “OmniSQL Access Module.” Contrast with EnterpriseConnect.
A DB2 sample program written in Assembler language that uses dynamic SQL. DSNTIAD is used to issue all SQL statements except SELECT in batch mode.
A file containing executable code and data bound to a program at load time or runtime, rather than during linking. The code and data in a dynamic link library can be shared by several applications simultaneously.
A unit of functional capability expressed by an individual command in an application program interface. See also application program interface.
Connectivity software that allows communication between two or more computer systems with different network architectures.
A LTM for MVS subsystem that ensures the transactions entered into the replication system are properly distributed, even following an interruption caused by the failure of one or more replication system components. See also Replication Agent for DB2.
An IBM z/OS system utility that performs copy operations including backup copying, unloading, reloading, and compressing partitioned data sets; and merging partitioned data sets to create new partitioned data sets. See also Multiple Virtual Storage.
A set of pointers that are logically ordered by the values of a key. Indexes are used to provide rapid access to data and can enforce uniqueness on the rows in a table.
A process for loading system programs and preparing a system to run jobs.
An IBM licensed program that serves as a full-screen editor and dialog manager. Used for writing application programs, ISPF provides a means of generating standard screen panels and interactive dialogues between the application programmer and terminal user.
A file containing information that Sybase Open Server/Open ClientConnect applications (including Replication Server and Adaptive Server) use to establish TCP/IP connections to other Open Server/Open ClientConnect applications. Sybase interfaces file names differ across platforms: interfaces for UNIX platforms, sql.ini for Windows NT, and win.ini for Windows. See also SYGWHOST macro and TCP/IP.
The internet protocol address at which TCP/IP expects to find the defined device. See also TCP/IP.
In z/OS, a control language used to identify a job and describe its requirements to an operating system. See also Multiple Virtual Storage.
A computer network located on the user’s premises and covering a limited geographical area. Communication within a local area network is not subject to external regulations; however, communication across the LAN boundary can be subject to some form of regulation.
The definition of memory allocation and usage for areas containing the commands and data passed from the Replication Extract to the Replication API. See also Replication API and Replication Extract.
A written record of operations performed, normally used for recovery. See also active log, archive log, or transaction log.
A subset of Replication Agent for DB2 that interacts with data sources to replicate logged transactions marked for replication. Replication Extract is the log extract supplied with Replication Agent for DB2. Replication Extract uses the Replication Application Program Interface (API) to convey the transactions to the Log Transfer Interface (LTI), which transforms them into Log Transfer Language (LTL) and sends them to a Replication Server. Replication Server then replicates the data changes to replicate databases. See also Log Transfer Interface, Log Transfer Language, Log Transfer Manager for z/OS, Replication API, and Replication Server.
A 6-byte value that DB2 generates and associates with each log record. The LRSN is contained in the DB2 log record header and tablespace header page. The LRSN replaces the RBA in a data-sharing environment, although each member continues to use the RBA for its own logs and BSDS. A number that DB2 generates and associates with each log record. DB2 also uses the LRSN for page versioning. The LRSNs generated by a given DB2 data-sharing group form a strictly increasing sequence for each DB2 log and a strictly increasing sequence for each page across the DB2 group. See also relative byte address.
A component of the Log Transfer Manager that provides the session between any z/OS-based Log Transfer Manager for z/OS and a Replication Server. The LTI receives z/OS data changes in Sybase Adaptive Server datatype values and transforms the changes into Log Transfer Language transactions, which are then sent to the Replication Server. See also Log Transfer Language, Log Transfer Manager for z/OS, and Replication Server.
The subset of the Replication Command Language that Log Transfer Manager for z/OS uses for submitting the information retrieved from the primary database transaction logs to Replication Server. See also primary database, Replication Agent for DB2, Replication Server, and transaction log.
An application that communicates updates made at a primary data server to Replication Server. Examples include the Log Transfer Manager for Sybase Adaptive Server, and Replication Agent for DB2, which consists of Sybase’s LTM for z/OS and Replication Extract. See also Database 2, LTM, Replication Agent for DB2, Replication Extract, and Replication Server.
Log Transfer Manager for z/OS is an application that communicates transactions identified by a Replication Extract to Replication Server. See also Replication Agent for DB2, Replication Extract, and Replication Server.
A file that contains the configuration parameters needed to operate LTM for MVS. A sample file is shipped in the hlq.JCL data set as the LTMCNFG member. See also Log Transfer Manager for z/OS.
An origin queue ID that identifies the last transaction operation successfully saved in Replication Server’s inbound queue. Replication Extract uses the LTM Locator to identify the location in the log to begin scanning during start-up and restart. See also origin queue ID and Replication Extract.
An IBM or IBM-compatible computer that conforms to the System/370 or System/390 architecture and supports z/OS. Sometimes referred to as a host. See also Multiple Virtual Storage.
An identifier defined in the replicate database that is used by Replication Server to identify the Replication Server maintenance user. See also Replication Server.
The method or process by which data is placed into a replicate table in preparation for replication. See also replicate table.
A program unit that is discrete and identifiable with respect to compiling, combining with other units, and loading; for example, the input to or output from an assembler, compiler, linkage editor, or executive routine.
The process of populating a replicate database using Replication Server commands that allows client applications to execute transactions against the primary database while the subscription data is unloaded.
A system that is characterized by many small, simple, short-duration transactions from many users. These transactions tend to be oriented toward data manipulation (insert, update, delete), and to only reference one or a few tables.
A Sybase product that provides customer applications, third-party products, and other Sybase products with the interfaces required to communicate with Open ClientConnect and Open ServerConnect applications. Open ClientConnect allows Open Client-style communication between DB2 and Replication Server.
The combination of Open ClientConnect and Open ServerConnect, which provide the connectivity backbone for Sybase’s distributed client-server architecture.
A Sybase product that provides the tools and interfaces required to create a custom server. Clients can route requests to DirectConnect through an Open Server that they configured to meet specific needs, such as the preprocessing of SQL statements or decision making about routing RPCs to Transaction Router Service for DB2 or to other servers.
A group of programs that translates commands to the computer, helping to perform such tasks as creating files, running programs, and printing documents.
An identifier built by Replication Extract that uniquely identifies each transaction operation transmitted to Log Transfer Manager (LTM) for z/OS. Replication Server maintains the origin queue ID of the last update that was successfully stored in the Replication Server stable queue during a given connection. LTM for MVS requests this identifier from Replication Server upon start-up and restart. See also Log Transfer Manager for z/OS, LTM Locator, Replication Agent for DB2, Replication Extract, and Replication Server.
A routine that converts a primary database log record into a LTL record, which is then sent to Replication Server. See also Log Transfer Language and Replication Server.
Multiple sessions running simultaneously between two LUs across a single LU 6.2 conversation. See also session.
A method used to create a connection to determine the availability of a process or data source.
The version of a set of data in a replicated data system from which replication occurs. With Replication Agent for DB2, primary data is stored in DB2. See also Database 2, Replication Agent for DB2, and Replication Server.
The database that contains the transactions to be replicated or processed. See also primary data.
A DB2 table used as a source for replication or processing. See also Database 2, primary data, and primary database.
A temporary solution or by-pass of a problem to resolve a defect in a current unaltered release of a program.
A list constructed and maintained so that the next data element to be retrieved is the one stored first.
The DB2 relative byte address of the log record associated with the insert, update, or delete that Replication Agent for DB2 sends to Replication Server. Replication Server maintains the QID of the last update that was successfully stored in the Replication Server stable queue for this connection. Requesting this QID is part of the initial conversation that occurs between Replication Agent for DB2 and Replication Server (analogous to the get truncation point in Log Transfer Manager for Sybase Adaptive Server). See relative byte address.
The event control block passed to the Replication Extract at start-up that, when posted, indicates that there are messages for the Replication Extract. The Replication Extract can obtain the messages using the Replication API’s LTMSEND function call. See also Replication API and Replication Extract.
A collection of data in which relationships between data items are explicitly specified as equally accessible attributes. The data is viewed as being stored in tables consisting of columns (data items) and rows (units of information). Relational databases can be accessed by SQL requests. See also Structured Query Language.
The application that controls relational databases. See also relational database. Contrast with database management system.
The address of a byte in the DB2 log. The address is the byte’s offset from the beginning of the log.
The database to which Replication Server is replicating transactions. There can be more than one replicate database for each Replication Server. See also primary database and Replication Server.
A database management system table maintained by Replication Server. See also Replication Server.
Information copied from a primary database using Replication Server and stored in a replicate table. See also replicate table and Replication Server.
A data-processing system in which data is replicated in multiple databases to provide remote users with the benefit of local data access.
The Sybase application consisting of LTM for MVS and Replication Extract. Replication Agent for DB2 allows the replication of transactions from a primary database to replicate databases through Sybase’s Replication Server. See also Log Transfer Manager for z/OS, Replication Extract, and Replication Server.
An interface for LTM for MVS used by Replication Extracts to communicate transactions to Sybase’s replication system. See also application program interface, Log Transfer Manager for z/OS, and Replication Extract.
A description of a table for which subscriptions can be created. The definition, maintained by Replication Server, includes information about the columns in the table, the location of the primary version of the table, and some options that specify how the table can be used. See also Replication Server and subscription.
A log extract that is a component of Replication Agent for DB2. Replication Extract interacts with primary data servers to capture updates of transactions marked for replication. See also log extract and Replication Agent for DB2.
A DB2 table named LTMOBJECTS that controls the replication of DB2 data and each row of which identifies a primary DB2 table that has been registered by the user. See also Database 2.
A Sybase Open Server application that maintains replicate transactions received from a data source, which can be either the source data server or another Replication Server. See also Adaptive Server Enterprise.
A thread from a primary Replication Server into a replicate Replication Server used to transfer commands from the RSI outbound stable queue to the replicate Replication Server. There is one RSI thread for each replicate Replication Server that is a recipient of commands from the primary Replication Server. See also Replication Server and stable queue.
The system database in which Replication Server stores its system information. The tables reside in a Sybase Adaptive Server database. See also Database 2, Replication Server, and Adaptive Server Enterprise.
A programming guide for the Replication API and sample log extract programs to allow a customer or third-party vendor to develop a Log Extract program that interfaces with the Log Transfer Manager.
One or more database operations the application sends as one unit to the database. During a request, the application gives up control to the DBMS and waits for its response. Depending on the response, the application commits or rolls back the request. One or more requests can be grouped into a single unit of work.
Any facility of a computing system or operating system required by a job or task, including main storage, input/output devices, processing unit, data sets, and control or processing programs.
A transaction operation instructing the DBMS to ignore the changes requested in a transaction. See also transaction. Contrast with commit.
A connection from a primary Replication Server to a replicate Replication Server. See also Replication Server.
A DB2 facility that enables users to execute SQL statements without embedding them in an application program.
A store-and-forward queue in which Replication Server messages destined for a route or database connection are stored. Messages written into the stable queue remain there until they can be delivered to the replicate Replication Server or replicate database. See also Replication Server.
In programming languages, a language construct that represents a step in a sequence of actions or a set of declarations.
A named set of direct access storage device (DASD) volumes. DB2 data can be stored in storage groups. See also Database 2.
A language developed by IBM to process data in a relational database. SQL is an industry standard.
A request for Replication Server to maintain either a replicated copy of a table or a set of rows from a table in a database at a specified site. See also Replication Server.
The SYGWHOST TYPE=ENTRY macro, distributed in the XCPHPING member of the hlq.JCL data set, serves as a directory containing network addresses and other information that controls how Replication Agent for DB2 connects to other servers, and configures the Open ClientConnect component of LTM for MVS to use IBM TCP/IP for a TCP/IP connection between Replication Agent for DB2 and Replication Server. The SYGWHOST TYPE=ENTRY macro can be a member of a Partitioned Data Set (PDS) or a sequential file.
The Replication Agent for DB2 TCP/IP installation requires a SYGWHOST TYPE=ENTRY macro entry for each primary Replication Server in your replication system. You can define any number of Replication Server entries in the SYGWHOST macro.
The SYGWHOST TYPE=ENTRY macro replaces the interfaces file required in earlier versions of the Replication Agent for DB2 software. See also interfaces file and TCP/IP.
The method that ensures primary and replicate tables are equivalent. For example, if transaction number 100 is successful in the primary database, the 100th transaction in the replicate database should also be successful.
The process of initiating, configuring, monitoring, and adjusting applications on a system.
A set of z/OS systems communicating and cooperating with each other through certain multisystem hardware components and software services that protect customer workloads.
The person at a computer installation who designs, controls, and manages the use of the computer system.
In a relational database management system, a two-dimensional array of data or a named data object that contains a specific number of unordered rows composed of a grouping of columns specific for the table.
The database receiving the replicate data in a replication environment. Also known as a destination.
An z/OS control block used to communicate information about tasks within an address space. There is one TCB per task in an address space. An address space can support one or more tasks, but any task may reside in only one address space. See also Database 2 and Multiple Virtual Storage.
The process of recording the sequence in which the statements in a program are executed and, optionally, the values of the program variables used in the statements.
A group that can include zero, one, or many database transaction operations (including inserts, updates, and deletes) that are applied or rejected as a whole.
A condition in which all transactions in the primary database are applied in the replicate database in the same order that they were applied in the primary database.
The log of transactions kept by a database server. Replication Extract reads these logs to identify the changes to primary databases. See also log extract, Replication Agent for DB2, and Replication Extract.
A program that processes transactions. There are two kinds of transaction programs: application transaction programs and service transaction programs.
The process of copying transaction operations (updates, inserts, and deletes) to remote locations. The replicated transactions are then kept consistent with the primary transaction. See also data duplication and data replication.
A Sybase Adaptive Server SQL extension that allows procedural programming within a DBMS to access and manipulate data. See also Adaptive Server Enterprise and Structured Query Language.
A computer network communications protocol designed by the Department of Defense Advanced Research Projects Agency. Contrast with advanced program-to-program communications.
The location in a DBMS transaction log that separates the part of the log verifiably received by Replication Server from the part that has not yet been verifiably received. In Adaptive Server, the transaction log entries that precede the truncation point have already entered the replication system, so that portion of the log can be safely truncated. See also database management system, LTM Locator, origin queue ID, Replication Server, Adaptive Server Enterprise, and transaction log.
An operating system developed by Bell Laboratories that allows multiple programs to run and multiple users to work concurrently.
The log RBA of the beginning of a recovery unit. The UR identifier is the earliest relative byte address required to process the UR during restart. See also relative byte address.
A user-defined, custom-built, Replication Server function whose name and parameters exactly match the name and parameters of a replicated stored procedure.
A user-written transaction program that can be given control at a determined point in a program.
In Replication Agent for DB2, a program called by the Replication API’s LTMSEND function call to alter transaction operations before sending them to Replication Server. See also Replication API.
An alternative representation of data from one or more tables. A view can include all or some of the columns in a table. Refer to Sybase Adaptive Server or IBM DB2 documentation for more information about Adaptive Server views. See also Database 2 and Adaptive Server Enterprise.
