Glossary Access control list (ACL). The list of principals that have explicit permission (to publish, to subscribe to, and to request persistent delivery of a publication message) against a topic in the topic tree. The ACLs define the implementation of topic-based security. Aggregate. Pre-calculated and pre-stored summaries, kept in the data warehouse to improve query performance. Aggregation. An attribute-level transformation that reduces the level of detail of available data, for example, having a Total Quantity by Category of Items rather than the individual quantity of each item in the category. Application programming interface. An interface provided by a software product that enables programs to request services. Asynchronous messaging. A method of communication between programs in which a program places a message on a message queue, and then proceeds with its own processing without waiting for a reply to its message. Attribute. A field in a dimension table. BLOB. Binary large object, a block of bytes of data (for example, the body of a message) that has no discernible meaning, but is treated as one solid entity that cannot be interpreted. Commit. An operation that applies all the changes made during the current unit of recovery or unit of work. After the operation is complete, a new unit of recovery or unit of work begins. Composite key. A key in a fact table that is the concatenation of the foreign keys in the dimension tables. Computer. A device that accepts information (in the form of digitalized data) and manipulates it for some result based on a program or sequence of instructions about how the data is to be processed. Configuration. The collection of brokers, their execution groups, the message flows and sets that are assigned to them, and the topics and associated access control specifications. Continuous Data Replication. Refer to Enterprise Replication. DDL (data definition language). An SQL statement that creates or modifies the structure of a table or database, for example, CREATE TABLE, DROP TABLE, ALTER TABLE, or CREATE DATABASE. DML (data manipulation language). An INSERT, UPDATE, DELETE, or SELECT SQL statement. Data append. A data loading technique where new data is added to the database, leaving the existing data unaltered. Data cleansing. A process of data manipulation and transformation to eliminate variations and inconsistencies in data content. This is typically to improve the quality, consistency, and usability of the data. Data federation. The process of enabling data from multiple heterogeneous data sources to appear as though it is contained in a single relational database. Can also be referred to "distributed access." Data mart. An implementation of a data warehouse, typically with a smaller and more tightly restricted scope, such as for a department or workgroup. It can be independent, or derived from another data warehouse environment. © Copyright IBM Corp. 2007, 2008. All rights reserved. 531