Glossary

Glossary of terms used in replication systems.

active database – In a warm standby application, a database that is replicated to a standby database. See also warm standby application.
Adaptive Server – The Sybase version 11.5 and later relational database server. If you choose the RSSD option when configuring Replication Server, Adaptive Server maintains Replication Server system tables in the RSSD database.
application programming interface (API) – A predefined interface through which users or programs communicate with each other. Open Client and Open Server are examples of APIs that communicate in a client/server architecture. RCL, the Replication Command Language, is the Replication Server API.
applied function – A replicated function, associated with a function replication definition, that Replication Server delivers from a primary database to a subscribing replicate database. The function passes parameter values to a stored procedure that is executed at the replicate database. The stored procedure executed at the replicate database by the maintenance user. See also replicated function delivery, request function, and function replication definition.
article – A replication definition extension for tables or stored procedures that can be an element of a publication. Articles may or may not contain where clauses, which specify a subset of rows that the replicate database receives.
asynchronous procedure delivery – A method of replicating, from a source to a destination database, a stored procedure that is associated with a table replication definition.
asynchronous command – A command that a client submits where the client is not prevented from proceeding with other operations before the completion status is received. Many Replication Server commands function as asynchronous commands within the replication system.
atomic materialization – A materialization method that copies subscription data from a primary to a replicate database through the network in a single atomic operation, using a select operation with a holdlock. No changes to primary data are allowed until data transfer is complete. Replicate data may be applied either as a single transaction or in increments of ten rows per transaction, which ensures that the replicate database transaction log does not fill. Atomic materialization is the default method for the create subscription command. See also nonatomic materialization, bulk materialization and no materialization.
autocorrection – Autocorrection is a setting applied to replication definitions, using the set autocorrection command, to prevent failures caused by missing or duplicate rows in a copy of a replicated table. When autocorrection is enabled, Replication Server converts each update or insert operation into a delete followed by an insert. Autocorrection should only be enabled for replication definitions whose subscriptions use nonatomic materialization.
base class – A function-string class that does not inherit function strings from a parent class. See also function-string class.
bitmap subscription – A type of subscription that replicates rows based on bitmap comparisons. Create columns using the int datatype, and identify them as the rs_address datatype when you create a replication definition. When you create a subscription, compare each rs_address column to a bitmask using a bitmap comparison operator (&) in the where clause. Rows matching the subscription’s bitmap are replicated.
bulk copy-in – A feature that improves Replication Server performance when replicating large batches of insert statements on the same table in Adaptive Server® Enterprise 12.0 and later. Replication Server implements bulk copy-in in Data Server Interface (DSI), the Replication Server module responsible for sending transactions to replicate databases, using the Open Client™ Open Server™ Bulk-Library.
Bulk copy-in also improves the performance of subscription materialization. When dsi_bulk_copy is on, Replication Server uses bulk copy-in to materialize the subscriptions if the number of insert commands in each transaction exceeds dsi_bulk_threshold.
bulk materialization – A materialization method whereby subscription data in a replicate database is initialized outside of the replication system. For example, data may be transferred from a primary database using media such as magnetic tape, diskette, CD-ROM, or optical storage disk. Bulk materialization involves a series of commands, starting with define subscription. You can use bulk materialization for subscriptions to table replication definitions or function replication definitions. See also atomic materialization, nonatomic materialization, and no materialization.
centralized database system – A database system where data is managed by a single database management system at a centralized location.
class – See error class and function-string class.
class tree – A set of function-string classes, consisting of two or more levels of derived and parent classes, that derive from the same base class. See also function-string class.
client – A program connected to a server in a client/server architecture. It may be a front-end application program executed by a user or a utility program that executes as an extension of the system.
Client/Server Interfaces (C/SI) – The Sybase interface standard for programs executing in a client/server architecture.
concurrency – The ability of multiple clients to share data or resources. Concurrency in a database management system depends upon the system protecting clients from conflicts that arise when data in use by one client is modified by another client.
connection – A connection from a Replication Server to a database. See also Data Server Interface (DSI) and logical connection.
connection profiles – Connection profiles allow you to configure your connection with a pre-defined set of properties.
coordinated dump – A set of database dumps or transaction dumps that is synchronized across multiple sites by distributing an rs_dumpdb or rs_dumptran function through the replication system.
database – A set of related data tables and other objects that is organized and presented to serve a specific purpose.
database generation number – Stored in both the database and the RSSD of the Replication Server that manages the database, the database generation number is the first part of the origin queue ID (qid) of each log record. The origin queue ID ensures that the Replication Server does not process duplicate records. During recovery operations, you may need to increment the database generation number so that Replication Server does not ignore records submitted after the database is reloaded.
database replication definition – A description of a set of database objects—tables, transactions, functions, system stored procedures, and DDL—for which a subscription can be created.
You can also create table replication definitions and function replication definitions. See also table replication definition and function replication definition.
database server – A server program, such as Sybase Adaptive Server, that provides database management services to clients.
data definition language (DDL) – The set of commands in a query language, such as Transact-SQL, that describes data and their relationships in a database. DDL commands in Transact-SQL include those using the create, drop, and alter keywords.
data manipulation language (DML) – The set of commands in a query language, such as Transact-SQL, that operates on data. DML commands in Transact-SQL include select, insert, update, and delete.
data server – A server whose client interface conforms to the Sybase Client/Server Interfaces and provides the functionality necessary to maintain the physical representation of a replicated table in a database. Data servers are usually database servers, but they can also be any data repository with the interface and functionality Replication Server requires.
Data Server Interface (DSI) – Replication Server threads corresponding to a connection between a Replication Server and a database. DSI threads submit transactions from the DSI outbound queue to a replicate data server. They consist of a scheduler thread and one or more executor threads. The scheduler thread groups the transactions by commit order and dispatches them to the executor threads. The executor threads map functions to function strings and execute the transactions in the replicate database. DSI threads use an Open Client connection to a database. See also outbound queue and connection.
data source – A specific combination of a database management system (DBMS) product such as a relational or non-relational data server, a database residing in that DBMS, and the communications method used to access that DBMS from other parts of a replication system. See also database and data server.
decision support application – A database client application characterized by ad hoc queries, reports, and calculations and few data update transactions.
declared datatype – The datatype of the value delivered to the Replication Server from the Replication Agent:
- If the Replication Agent delivers a base Replication Server datatype, such as datetime, to the Replication Server, the declared datatype is the base datatype.
- Otherwise, the declared datatype must be the UDD for the original datatype at the primary database.
default function string – The function string that is provided by default for the system-provided classes rs_sqlserver_function_class and rs_default_function_class and classes that inherit function strings from these classes, either directly or indirectly. See also function string.
dematerialization – The optional process, when a subscription is dropped, whereby specific rows that are not used by other subscriptions are removed from the replicate database.
derived class – A function-string class that inherits function strings from a parent class. See also function-string class and parent class.
direct route – A route used to send messages directly from a source to a destination Replication Server, with no intermediate Replication Servers. See also indirect route and route.
disk partition – See partition.
distributed database system – A database system where data is stored in multiple databases on a network. The databases may be managed by data servers of the same type (for example, Adaptive Server) or by heterogeneous data servers.
Distributor – A Replication Server thread (DIST) that helps to determine the destination of each transaction in the inbound queue.
dump marker – A message written by Adaptive Server in a database transaction log when a dump is performed. In a warm standby application, when you are initializing the standby database with data from the active database, you can specify that Replication Server use the dump marker to determine where in the transaction stream to begin applying transactions in the standby database. See also warm standby application.
Embedded Replication Server System Database (ERSSD) – The SQL Anywhere (SA) database that stores Replication Server system tables. You can choose whether to store Replication Server system tables on the ERSSD or the Adaptive Server RSSD. See also Replication Server System Database (RSSD).
Enterprise Connect Data Access (ECDA) – An integrated set of software applications and connectivity tools that allow access to data within a heterogeneous database environment, such as a variety of LAN-based, non-ASE data sources, and mainframe data sources.
ExpressConnect for Oracle – A set of libraries that can be used to provides direct communication between Replication Server and an Oracle database.
error action – A Replication Server response to a data server error. Possible Replication Server error actions are ignore, warn, retry_log, log, retry_stop, and stop_replication. Error actions are assigned to specific data server errors.
error class – A name for a collection of data server error actions that are used with a specified database.
exceptions log – A set of three Replication Server system tables that holds information about transactions that failed on a data server. The transactions in the log must be resolved by a user or by an intelligent application. You can use the rs_helpexception stored procedure to query the exceptions log.
Failover – Sybase Failover allows you to configure two version 12.0 and later Adaptive Servers as companions. If the primary companion fails, that server’s devices, databases, and connections can be taken over by the secondary companion.
For more detailed information about how Sybase Failover works in Adaptive Server, refer to Using Sybase Failover in a High Availability System, which is part of the Adaptive Server Enterprise documentation set.
fault tolerance – The ability of a system to continue to operate correctly even though one or more of its component parts is malfunctioning.
function – A Replication Server object that represents a data server operation such as insert, delete, select, or begin transaction. Replication Server distributes such operations to other Replication Servers as functions. Each function consists of a function name and a set of data parameters. In order to execute the function in a destination database, Replication Server uses function strings to convert a function to a command or set of commands for a type of database. See also user-defined function, and replicated function delivery.
function replication definition – A description of a replicated function used in replicated function delivery. The function replication definition, maintained by Replication Server, includes information about the parameters to be replicated and the location of the primary version of the affected data. There are two types of function replication definition, applied and request. See also replicated function delivery.
function scope – The range of a function’s effect. Functions have replication definition scope or function-string class scope. A function with replication definition scope is defined for a specific replication definition, and cannot be applied to other replication definitions. A function with function-string class scope is defined once for a function-string class and is available only within that class.
function string – A string that Replication Server uses to map a database command to a data server API. For the rs_select and rs_select_with_lock functions only, the string contains an input template, used to match function strings with the database command. For all functions, the string also contains an output template, used to format the database command for the destination data server.
function-string class – A named collection of function strings used with a specified database connection. Function-string classes include those provided with Replication Server and those you have created. Function-string classes can share function string definitions through function-string inheritance. The three system-provided function-string classes are rs_sqlserver_function_class, rs_default_function_class, and rs_db2_function_class. See also base class, class tree, derived class, function-string inheritance, and parent class.
function-string inheritance – The ability to share function string definitions between classes, whereby a derived class inherits function strings from a parent class. See also derived class, function-string class, and parent class.
function-string variable – An identifier used in a function string to represent a value that is to be substituted at run time. Variables in function strings are enclosed in question marks (?). They represent column values, function parameters, system-defined variables, or user-defined variables.
function subscription – A subscription to a function replication definition (used in both applied and request function delivery).
gateway – Connectivity software that allows two or more computer systems with different network architectures to communicate.
generation number – See database generation number.
heterogeneous data servers – Multi-vendor data servers used together in a distributed database system.
hibernation mode – A Replication Server state in which all DDL commands, except admin and sysadmin commands, are rejected; all routes and connections are suspended; most service threads, such as DSI and RSI, are suspended; and RSI and RepAgent users are logged off and not allowed to log on. Used during route upgrades, and may be turned on for a Replication Server to debug problems.
high availability (HA) – Very low downtime. Computer systems that provide HA usually provide 99.999% availability, or roughly five minutes unscheduled downtime per year.
high volume adaptive replication (HVAR) – Compilation of a group of insert, delete, and update operations to produce a net result and the subsequent bulk application of the net result to the replicate database.
hot standby application – A database application in which the standby database can be placed into service without interrupting client applications and without losing any transactions. See also warm standby application.
ID Server – One Replication Server in a replication system is the ID Server. In addition to performing the usual Replication Server tasks, the ID Server assigns unique ID numbers to every Replication Server and database in the replication system, and maintains version information for the replication system.
inbound queue – A stable queue used to spool messages from a Replication Agent to a Replication Server.
indirect route – A route used to send messages from a source to a destination Replication Server, through one or more intermediate Replication Servers. See also direct route and route.
interfaces file – A file containing entries that define network access information for server programs in a Sybase client/server architecture. Server programs may include Adaptive Servers, gateways, Replication Servers, and Replication Agents. The interfaces file entries enable clients and servers to connect to each other in a network.
latency – The measure of the time it takes to distribute to a replicate database a data modification operation first applied in a primary database. The time includes Replication Agent processing, Replication Server processing, and network overhead.
local-area network (LAN) – A system of computers and devices, such as printers and terminals, connected by cabling for the purpose of sharing data and devices.
locator value – The value stored in the rs_locater table of the Replication Server’s RSSD that identifies the latest log transaction record received and acknowledged by the Replication Server from each previous site during replication.
logical connection – A database connection that Replication Server maps to the connections for the active and standby databases in a warm standby application. See also connection and warm standby application.
login name – The name that a user or a system component such as Replication Server uses to log in to a data server, Replication Server, or Replication Agent.
Log Transfer Language (LTL) – A subset of the Replication Command Language (RCL). A Replication Agent such as RepAgent uses LTL commands to submit to Replication Server the information it retrieves from primary database transaction logs.
Log Transfer Manager (LTM) – The Replication Agent program for Sybase SQL Server. See also Replication Agent and RepAgent thread.
maintenance user – A data server login name that Replication Server uses to maintain replicate data. In most applications, maintenance user transactions are not replicated.
materialization – The process of copying data specified by a subscription from a primary database to a replicate database, thereby initializing the replicate table. Replicate data can be transferred over a network, or, for subscriptions involving large amounts of data, loaded initially from media. See also atomic materialization, bulk materialization, no materialization, and nonatomic materialization.
materialization queue – A stable queue used to spool messages related to a subscription being materialized or dematerialized.
missing row – A row missing from a replicated copy of a table but present in the primary table.
mixed-version system – A replication system containing Replication Servers of different software versions that have different capabilities based on their different software versions and site versions. Mixed-version support is available only if the system version is 11.0.2 or greater.
For example, a replication system containing Replication Servers version 11.5 or later and version 11.0.2 is a mixed-version system. A replication system containing Replication Servers of releases earlier than release 11.0.2 is not a mixed-version system, because any newer Replication Servers are restricted by the system version from using certain new features. See also site version and system version.
more columns – Columns in a replication definition exceeding 250, but limited to 1024. More columns are supported by Replication Server version 12.5 and later.
multi-site availability (MSA) – Methodology for replicating database objects—tables, functions, transactions, system stored procedures, and DDL from the primary to the replicate database. See also database replication definition.
name space – The scope within which an object name must be unique.
nonatomic materialization – A materialization method that copies subscription data from a primary to a replicate database through the network in a single operation, without a holdlock. Changes to the primary table are allowed during data transfer, which may cause temporary inconsistencies between replicate and primary databases. Data is applied in increments of ten rows per transaction, which ensures that the replicate database transaction log does not fill. Nonatomic materialization is an optional method for the create subscription command. See also autocorrection, atomic materialization, no materialization, and bulk materialization.
network-based security – Secure transmission of data across a network. Replication Server supports third-party security mechanisms that provide user authentication, unified login, and secure message transmission between Replication Servers.
no materialization – A materialization method that lets you create a subscription when the subscription data already exists at the replicate site. Use the create subscription command with the without materialization clause. You can use this method to create subscriptions to table replication definitions and function replication definitions. See also atomic materialization and bulk materialization.
online transaction processing (OLTP) application – A database client application characterized by frequent transactions involving data modification (inserts, deletes, and updates).
Origin Queue ID (qid) – Formed by the RepAgent, the qid uniquely identifies each log record passed to the Replication Server. It includes the date and timestamp and the database generation number. See also database generation number.
orphaned row – A row in a replicated copy of a table that does not match an active subscription.
outbound queue – A stable queue used to spool messages. The DSI outbound queue spools messages to a replicate database. The RSI outbound queue spools messages to a replicate Replication Server.
parallel DSI – Configuring a database connection so that transactions are applied to a replicate data server using multiple DSI threads operating in parallel, rather than a single DSI thread. See also connection and Data Server Interface (DSI).
parameter – An identifier representing a value that is provided when a procedure executes. Parameter names are prefixed with an @ character in function strings. When a procedure is called from a function string, Replication Server passes the parameter values, unaltered, to the data server. See also searchable parameter.
parent class – A function-string class from which a derived class inherits function strings. See also function-string class and derived class.
partition – A raw disk partition or operating system file that Replication Server uses for stable queue storage. Only use operating system files in a test environment.
physical connection – See connection.
primary data – The definitive version of a set of data in a replication system. The primary data is maintained on a data server that is known to all of the Replication Servers with subscriptions for the data.
primary database – Any database that contains data that is replicated to another database via the replication system.
primary fragment – A horizontal segment of a table that holds the primary version of a set of rows.
primary key – A set of table columns that uniquely identifies each row.
primary site – A Replication Server where a function-string class or error class is defined. See error class and function-string class.
principal user – The user who starts an application. When using network-based security, Replication Server logs in to remote servers as the principal user.
profiles – Profiles allow you to configure your connection with a pre-defined set of properties.
projection – A vertical slice of a table, representing a subset of the table’s columns.
publication – A group of articles from the same primary database. A publication lets you collect replication definitions for related tables and/or stored procedures and then subscribe to them as a group. You collect replication definitions as articles in a publication at the source Replication Server and subscribe to them with a publication subscription at the destination Replication Server. See also article and publication subscription.
publication subscription – A subscription to a publication. See also article and publication.
published datatype – The datatype of the column after the column-level translation (and before a class-level translation, if any) at the replicate data server. The published datatype must be either a Replication Server base datatype or a UDD for the datatype in the target data server. If the published datatype is omitted from the replication definition, it defaults to the declared datatype.
query – In a database management system, a query is a request to retrieve data that meets a given set of criteria. The SQL database language includes the select command for queries.
quiescent – A quiescent replication system is one in which all updates have been propagated to their destinations. Some Replication Server commands or procedures require that you first quiesce the replication system.
quoted identifiers – Object names that contain special characters such as spaces and non-alphanumeric characters, start with a character other than an alphabet, or that correspond to a reserved word, need to be enclosed in double quote characters to be parsed correctly.
real time loading (RTL) – High volume adaptive replication (HVAR) to a Sybase IQ database. Uses relevant commands and processes to apply HVAR changes to a Sybase IQ replicate database. See high volume adaptive replication.
remote procedure call (RPC) – A request to execute a procedure that resides in a remote server. The server that executes the procedure could be a Adaptive Server, a Replication Server, or a server created using Open Server. The request can originate from any of these servers or from a client application. The RPC request format is a part of the Sybase Client/Server Interfaces.
RepAgent thread – The Replication Agent for Adaptive Server databases. RepAgent is an Adaptive Server thread; it transfers transaction log information from the primary database to a Replication Server for distribution to other databases.
replicate database – Any database that contains data that is replicated from another database via the replication system.
replicated function delivery – A method of replicating, from a source to a destination database, a stored procedure that is associated with a function replication definition. See also applied function, request function, and function replication definition.
replicated stored procedure – An Adaptive Server stored procedure that is marked as replicated using the sp_setrepproc or the sp_setreplicate system procedure. Replicated stored procedures can be associated with function replication definitions or table replication definitions. See also replicated function delivery and asynchronous procedure delivery.
replicated table – A table that is maintained by Replication Server, in part or in whole, in databases at multiple locations. There is one primary version of the table, which is marked as replicated using the sp_setreptable or the sp_setreplicate system procedure; all other versions are replicated copies.
Replication Agent – A program or module that transfers transaction log information representing modifications made to primary data from a database server to a Replication Server for distribution to other databases. RepAgent is the Replication Agent for Adaptive Server databases.
Replication Command Language (RCL) – The commands used to manage information in Replication Server.
replication definition – Usually, a description of a table for which subscriptions can be created. The replication definition, maintained by Replication Server, includes information about the columns to be replicated and the location of the primary version of the table.
You can also create function replication definitions; sometimes the term “table replication definition” is used to distinguish between table and function replication definitions. See also function replication definition.
Replication Server – The Sybase server program that maintains replicated data, typically on a LAN, and processes data transactions received from other Replication Servers on the same LAN or on a WAN.
Replication Server Interface (RSI) – A thread that logs in to a destination Replication Server and transfers commands from the RSI outbound stable queue to the destination Replication Server. There is one RSI thread for each destination Replication Server that is a recipient of commands from a primary or intermediate Replication Server. See also outbound queue and route.
Replication Monitoring Services (RMS) – A small Java application built using the Sybase Unified Agent Framework (UAF) that monitors and troubleshoot a replication environment.
replication system administrator – The system administrator that manages routine operations in the Replication Server.
Replication Server System Database (RSSD) – The Adaptive Server database containing a Replication Server system tables. You can choose whether to store Replication Server system tables on the RSSD or the SQL Anywhere (SA) ERSSD. See also Embedded Replication Server System Database (ERSSD).
Replication Server system Adaptive Server – The Adaptive Server with the database containing a Replication Server’s system tables (the RSSD).
replication system – A data processing system where data is replicated in multiple databases to provide remote users with the benefits of local data access. Specifically, a replication system that is based upon Replication Server and includes other components such as Replication Agents and data servers.
replication system domain – All replication system components that use the same ID Server.
request function – A replicated function, associated with a function replication definition, that Replication Server delivers from a primary database to a replicate database. The function passes parameter values to a stored procedure that is executed at the replicate database. The stored procedure is executed at the replicate site by the same user as it is at the primary site.See also replicated function delivery, request function, and function replication definition.
resync marker – When you restart Replication Agent in resync mode, Replication Agent sends the resync database marker to Replication Server to indicate that a resynchronization effort is in progress. The resync marker is the first message Replication Agent sends before sending any SQL data definition language (DDL) or data manipulation language (DML) transactions.
route – A one-way message stream from a source Replication Server to a destination Replication Server. Routes carry data modification commands (including those for RSSDs) and replicated functions or stored procedures between Replication Servers. See also direct route and indirect route.
route version – The lower of the site version numbers of the route’s source and destination Replication Servers. Replication Server version 11.5 and later use the route version number to determine which data to send to the replicate site. See also site version.
row migration – The process whereby column value changes in rows in a primary version of a table cause corresponding rows in a replicate version of the table to be inserted or deleted, based on comparison with values in a subscription’s where clause.
SQL Server – The Sybase relational database pre-11.5 server.
SQL statement replication – In SQL statement replication, the Replication Server receives the SQL statement that modified the primary data, rather than the individual row changes from the transaction log. Replication Server applies the SQL statement to the replicated site. RepAgent sends both the SQL Data Manipulation Language (DML) and individual row changes. Depending on your configuration, Replication Server chooses either individual row change log replication or SQL statement replication.
schema – The structure of the database. DDL commands and system procedures change system tables stored in the database. Supported DDL commands and system procedures can be replicated to standby databases when you use Replication Server version 11.5 or later and Adaptive Server version 11.5 or later.
searchable column – A column in a replicated table that can be specified in the where clause of a subscription or article to restrict the rows replicated at a site.
searchable parameter – A parameter in a replicated stored procedure that can be specified in the where clause of a subscription to help determine whether or not the stored procedure should be replicated. See also parameter.
secondary truncation point – See truncation point.
site – An installation consisting of, at minimum, a Replication Server, data server, and database, and possibly a Replication Agent, usually at a discrete geographic location. The components at each site are connected over a WAN to those at other sites in a replication system. See also primary site.
site version – The version number for an individual Replication Server. Once the site version has been set to a particular level, the Replication Server enables features specific to that level, and downgrades are not allowed. See also software version, route version, and system version.
software version – The version number of the software release for an individual Replication Server. See also site version and system version.
Stable Queue Manager (SQM) – A thread that manages the stable queues. There is one Stable Queue Manager (SQM) thread for each stable queue accessed by the Replication Server, whether inbound or outbound.
Stable Queue Transaction (SQT) interface – A thread that reassembles transaction commands in commit order. A Stable Queue Transaction (SQT) interface thread reads from inbound stable queues, puts transactions in commit order, then sends them to the Distributor (DIST) thread or a DSI thread, depending on which thread required the SQT ordering of the transaction.
stable queues – Store-and-forward queues where Replication Server stores messages destined for a route or database connection. Messages written into a stable queue remain there until they can be delivered to the destination Replication Server or database. Replication Server builds stable queues using its disk partitions. See also inbound queue, outbound queue, and materialization queue.
standalone mode – A special Replication Server mode used for initiating recovery operations.
standby database – In a warm standby application, a database that receives data modifications from the active database and serves as a backup of that database. See also warm standby application.
stored procedure – A collection of SQL statements and optional control-of-flow statements stored under a name in a Adaptive Server database. Stored procedures supplied with Adaptive Server are called system procedures. Some stored procedures for querying the RSSD are included with the Replication Server software.
subscription – A request for Replication Server to maintain a replicated copy of a table, or a set of rows from a table, in a replicate database at a specified location. You can also subscribe to a function replication definition, for replicating stored procedures.
subscription dematerialization – See dematerialization.
subscription materialization – See materialization.
subscription migration – See row migration.
Sybase Central – A graphical tool that provides a common interface for managing Sybase and Powersoft products. Replication Server uses Replication Manager as a Sybase Central plug-in. See also Replication Monitoring Services (RMS).
symmetric multiprocessing (SMP) – On a multiprocessor platform, the ability of an application’s threads to run in parallel. Replication Server supports SMP, which can improve server performance and efficiency.
synchronous command – A command that a client considers complete only after the completion status is received.
system function – A function that is predefined and part of the Replication Server product. Different system functions coordinate replication activities, such as rs_begin, or perform data manipulation operations, such as rs_insert, rs_delete, and rs_update.
system-provided classes – Replication Server provides the error class rs_sqlserver_error_class and the function-string classes rs_sqlserver_function_class, rs_default_function_class, and rs_db2_function_class. Function strings are generated automatically for the system-provided function-string classes and for any derived classes that inherit from these classes, directly or indirectly. See also error class and function-string class.
system version – The version number for a replication system that represents the version for which new features are enabled, for Replication Servers of release 11.0.2 or earlier, and below which no Replication Server can be downgraded or installed. For a Replication Server version 11.5, your use of certain new features requires a site version of 1150 and a system version of at least 1102. See also mixed-version system, site version, and software version.
table replication definition – See replication definition.
table subscription – A subscription to a table replication definition.
thread – A process running within Replication Server. Built upon Sybase Open Server, Replication Server has a multi-threaded architecture. Each thread performs a certain function such as managing a user session, receiving messages from a Replication Agent or another Replication Server, or applying messages to a database. See also Data Server Interface (DSI), Distributor, and Replication Server Interface (RSI).
transaction – A mechanism for grouping statements so that they are treated as a unit: either all statements in the group are executed or no statements in the group are executed.
Transact-SQL – The relational database language used with Adaptive Server. It is based on standard SQL (Structured Query Language), with Sybase extensions.
truncation point – An Adaptive Server database that holds primary data has an active truncation point, marking the transaction log location where Adaptive Server has completed processing. This is the primary truncation point.
The RepAgent for an Adaptive Server database maintains a secondary truncation point, marking the transaction log location separating the portion of the log successfully submitted to the Replication Server from the portion not yet submitted. The secondary truncation point ensures that each operation enters the replication system before its portion of the log is truncated.
user-defined function – A function that allows you to create custom applications that use Replication Server to distribute replicated functions or asynchronous stored procedures between sites in a replication system. In replicated function delivery, a user-defined function is automatically created by Replication Server when you create a function replication definition.
variable – See function-string variable.
version – mixed-version system
See mixed-version system, site version, software version, and system version.
warm standby application – An application that employs Replication Server to maintain a standby database for a database known as the active database. If the active database fails, Replication Server and client applications can switch to the standby database.
wide-area network (WAN) – A system of local-area networks (LANs) connected together with data communication lines.
wide columns – Columns in a replication definition containing char, varchar, binary, varbinary, unichar, univarchar, or Java inrow data that are wider that 255 bytes. Wide columns are supported by Replication Server version 12.5 and later.
wide data – Wide data rows, limited to the size of the data page on the data server. Adaptive Server supports page sizes of 2K, 4K, 8K, and 16K. Wide data is supported by Replication Server version 12.5 and later.
wide messages – Messages larger that 16K that span blocks. Wide messages are supported by Replication Server version 12.5 and later.