Teradata is a
Relational Database Management System, designed for organisations that need data to be retrieved very quickly from a large
database. It is therefore the RDMS of choice for six of the top ten
retailers, six of the top nine
telcos and six of the top seven
airlines, and can commonly be found in
banks,
government bureaux and
insurance companies.
Teradata is noted for being
scalable, robust and capable of handling a large number of users at any given time. It can run on
UNIX,
Windows NT and
Windows 2000.
What makes Teradata fast, and unique, is the proprietary technology that gives it parallelism, the ability to break queries down to individual units, and then share the work out to individual microprocessors called AMPs (Access Module Processors).
Teradata system comprises of any number of nodes an organisation decides to buy. A node first checks if a table isn't locked or the user isn' t some kind of intruder, and if it is happy it will then interpret an SQL query with its parsing engine. The parsing engine's parser will interpret the query, the optimiser will work out which is the most efficient way to handle it with the available resources, and the dispatcher will control the sequential operation of requests. The BYNET will then break up the query into individual units as determined by the optimizer, sending requests to any number of AMPs. A technique called hash positioning randomly and evenly distributes data across all the AMPs, to ensure that performance is balanced.
These AMPs are virtual processors responsible for managing a portion of the database, and do all the sorting, aggregating and other grunt work needed to process answers from upto 64 physical disks. The results are carried back to the node via the BYNET.
Teradata produces two tools for interrogating databases, BTEQ (Basic Teradata Query Utility) suited for both ad hoc and scripted batch processing, and a zippier Queryman (Teradata Query Manager)
Teradata was formed as Teradata Corp. in Los Angeles in 1979, but since 1992 has been merged with NCR.