Glossary

1-safe algorithm. A method of transaction processing in HotStandby setups. In 1-safe systems, transactions are committed on the primary server and then propagated to the secondary server after If the primary server fails before it sends the transactions to the secondary server, the transactions will not be visible on the secondary server. Also see 2-safe algorithm.

2-safe algorithm. A method of transaction processing in HotStandby setups. In 2-safe systems, transactions are not considered committed on the primary server until the transaction is confirmed committed on the secondary server. All updates to the data are applied to both copies synchronously. If the secondary server fails, the primary server stops accepting transactions. Also see 1-safe algorithm.

Access mode. The access mode of a solidDB parameter defines whether the parameter can be changed dynamically through an ADMIN COMMAND, and when the change takes effect. The possible access modes are RO, RW, RW/Startup, RW/Create.

application programming interface (API). An interface provided by a software product that enables programs to request services.

binary large object (BLOB). A block of bytes of data (for example, the body of a message) that has no discernible meaning, but is treated as one entity that cannot be interpreted.

Bonsai Tree. A small active index (data storage tree) that stores new data (deletes, inserts, updates) in central memory efficiently, while maintaining multiversion information.

cache database. The solidDB database in a

Universal Cache setup. Also called cache or front-end.

concurrency control. A method for preventing two different users from trying to update the same data in a database at the same time.

Data Definition Language (DDL). An SQL statement that creates or modifies the structure of a table or database, for example, CREATE TABLE, DROP TABLE, ALTER TABLE, CREATE DATABASE.

Data Manipulation Language (DML). An INSERT, UPDATE, DELETE, or SELECT SQL statement.

data store (InfoSphere CDC). A management entity that represents the InfoSphere CDC instance in Management Console.

deploy. The process of making operational the configuration and topology of the solidDB Universal Cache.

disk-based table (D-table). A table that has its contents stored primarily on disk so that the server copies only small amounts of data at a time into memory. Also see in-memory table.

distributed application A set of application programs that collectively constitute a single application.

durability level. A feature of transactionality that controls how solidDB handles transaction logging. solidDB supports three durability levels: strict, relaxed, and adaptive.

Dynamic SQL. SQL that is interpreted during execution of the statement.

Instance (InfoSphere CDC). A runtime instance of the InfoSphere CDC replication engine for a given DBMS.

Java Database Connectivity (JDBC). An API that has the same characteristics as ODBC but is specifically designed for use by Java database applications.

Java developer kit. A software package used to write, compile, debug, and run Java applets and applications.

Java Message Service. An application programming interface that provides Java language functions for handling messages.

Java runtime environment. A subset of the Java developer kit that allows you to run Java applets and applications.

In-memory table (M-table). A table whose contents are entirely stored in memory so that the data can be accessed as quickly as possible. Also see disk-based table.

main-memory engine (MME). The solidDB component that takes care of operations concerning in-memory tables.

meta data. Typically called data (or information) about data. It describes or defines data elements.

multi-threading. A capability that enables multiple concurrent operations to use the same process.

Open Database Connectivity (ODBC). A standard API for accessing data in both relational and non-relational database management systems. Using this API, database applications can access data stored in database management systems on a variety of computers even if each database management system uses a different data storage format and programming interface. ODBC is based on the call level interface (CLI) specification of the X/Open SQL Access Group.

optimization. The capability to enable a process to execute and perform in such a way as to maximize performance, minimize resource utilization, and minimize the process execution response time delivered to the user.

partition. Part of a database that consists of its own data, indexes, configuration files, and transaction logs.

Primary Key. A field in a table that is uniquely different for each record in the table.

process. An instance of a program running in a computer.

replication (InfoSphere CDC). InfoSphere CDC replication is based on an asynchronous, push-based model. Unidirectional subscriptions can be created for real-time propagation of data changes from the source side to the target side. Bidirectional capability is achieved by setting up two subscriptions with mirrored source and target definitions.

replication (HotStandby). In HotStandby (HSB) setups, data changes in the primary are propagated to the secondary using a push-based replication protocol. The protocol can be set to synchronous (2-safe) or asynchronous (1-safe).

replication (advanced replication). In advanced replication setups, an asynchronous pull-based replication method enables occasional distribution and synchronization of data across multiple database servers.

read-only (RO). Parameter access mode where the value cannot be changed; the current value is always identical to the startup value.

read-write (RW). Parameter access mode where the value can be changed through an ADMIN COMMAND and the change takes effect immediately.

RW/Startup. Parameter access mode where the value can be changed through an ADMIN COMMAND and the change takes effect the next time that the server starts.

RW/Create. Parameter access mode where the value can be changed through an ADMIN COMMAND and the change applies when a new database is created.