Teradata Study Guide

JDBC: Java Database Connectivity (JDBC) provides Java developers with a standard API (application Programming Interfaces) that is used to access databases regardless of the driver and database product. To use JDBC you'll need at least JDK 1.1 a database and a JDBC driver. There are several characteristics of JDBC:ODBC : ODBC is the acronym for Open DataBase Connectivity a Microsoft Universal Data Access standard that started life as the Windows implementation of the X/Open SQL Call Level Interface specification. ODBC Driver Manager - an application binds to this generic library which is responsible for loading the requested ODBC Driver. ODBC Driver - dynamically loaded by the ODBC Driver manager for making connection to target Database. Difference b/w them is 1.ODBC is for Microsoft and JDBC is for java applications. 2.ODBC can't be directly used with Java because it uses a C interface. 3.ODBC makes use of pointers which have been removed totally from java. ...

Table Type Specifications of SET VS MULTISET There are two different table type philosophies so there are two different type tables. They are SET and MULTISET. It has been said, “A man with one watch knows the time, but a man with two watches is never sure”. When Teradata was originally designed it did not allow duplicate rows in a table. If any row in the same table had the same values in every column Teradata would throw one of the rows out. They believed a second row was a mistake. Why would someone need two watches and why would someone need two rows exactly the same? This is SET theory and a SET table kicks out duplicate rows. The ANSI standard believed in a different philosophy. If two rows are entered into a table that are exact duplicates then this is acceptable. If a person wants to wear two watches then they probably have a good reason. This is a MULTISET table and duplicate rows are allowed. If you do not specify SET or MULTISET, one is used as a default. Here is the issue:...

Definition: Teradata SQL Assistant (TSA), as part of Teradata Tools and Utilities (TTU), is an ODBC-based client utility used to access and manipulate data on ODBC-compliant database servers. It has two editions: 1) Teradata SQL Assistant for Microsoft Windows 2) Teradata SQL Assistant/Web Edition Teradata SQL Assistant is an information discovery tool designed for Windows XP and Windows 2000. Teradata SQL Assistant retrieves data from any ODBC-compliant database server. The data can then be manipulated and stored on the desktop PC. Teradata SQL Assistant/Web Edition is a web-based query tool that allows you to compose queries, submit them to the Teradata Database, and then view the results in a web browser. Overview : Teradata SQL Assistant for Microsoft Windows, originally called "Queryman" (before V. 6.0)or "QueryMan" (V. 6.0 and up), is also known as "SQLA" among programmers. It supports import / export tasks, but not the serious ones. Wit...

PE, acronym for "Parsing Engine," is the type of vproc (Virtual Processor) for session control, task dispatching and SQL parsing in the multi-tasking and possibly parallel-processing environment of the Teradata Database. DEFINITION PE, acronym for "Parsing Engine," is the type of vproc (Virtual Processor) for session control, task dispatching and SQL parsing in the multi-tasking and possibly parallel-processing environment of the Teradata Database. Vproc is a software process running in an SMP (Symmetric Multiprocessing) environment or a node. COMPONENTS The components of a PE vproc can be classified as the following:    1. Parser: It desolves SQL statements into RDBMS processing steps;    2. Query Optimizer: It decides the optimal way to access data;    3. Step Generator: It 1) produces processing steps, and 2) encapsulates them into packages;    4. Dispatcher: It 1) transmits the encapsulated steps from the parser to the pertinen...

DEFINITION AMP, acronym for "Access Module Processor," is the type of vproc (Virtual Processor) used to manage the database, handle file tasks and and manipulate the disk subsystem in the multi-tasking and possibly parallel-processing environment of the Teradata Database. OVERVIEW In reality, each AMP is an instance of the database management software responsible for accessing and manipulating data. As such, every AMP is allowed a part of the database to manage, and a part of the physical disk space to keep its set of database tables. Usually, the AMP obtains its portion of the disk space by being associated with a virtual disk (vdisk). It handles its disk reading / writing by using its file system software, which converts AMP steps (i.e., the steps from PEs) into physical data block requests. The AMPs are responsible to access and manipulate the data so as to complete the request processing. There may be mutiple AMPs on one node, and the communication among the AMPs ...

DEFINITION Vproc, acronym for "Virtual PROCessor," is a self-contained instance of the processor software on a Teradata platform (SMP platform or a node). Vprocs are the basic units of parallelism that make up the Teradata database server. OVERVIEW To put it simply, a virtual processor is a simulated processor in a processing software system, or a software version of a dedicated physical processor. Each vproc uses a portion of the physical processor resource, and runs independently of other vprocs.  The vprocs co-existing within a node share a single memory pool - a collection of free memory in the node. The portion of memory allocated from the pool to one vproc will be returned to the pool after usage for use by other vprocs. Vprocs are the basic units of parallelism that make up the Teradata database server. A single SMP node is made up of multiple vprocs, and a single Teradata MPP system is made up of multiple SMP nodes.  Vprocs run as multi-threaded processes to...

DEFINITION BYNET, acronym for "BanYan NETwork," is a folded banyan switching network built upon the capacity of the YNET. It acts as a distributed multi-fabric inter-connect to link PEs, AMPs and nodes on a Massively Parallel Processing (MPP) system. OVERVIEW Interconnect technology is important for parallel computing. The BYNET is Teradata's "system interconnect for high-speed, fault tolerant warehouse-optimized messaging between nodes." [11] As an indispensable part of the Teradata MPP system, it can be understood better with its predecessor "YNET" in the background. In 1982, the YNET interconnecting technology used on the DBC 1012 was patented for the parallelism. As a broadcast-based hardware solution, it linked all the IFPs, COPs, and AMPs together with circuit boards and cables in a dual bus architecture. Two costom-built busses operated concurrently within the interconnect framework: YNET A to connect the IFPs and COPs on one side, and YNET ...

Symmetric multiprocessing (SMP) - A single node that contains multiple CPUs sharing a memory pool. Massively parallel processing (MPP) - Multiple SMP nodes working together comprise a larger configuration. The nodes are connected using the BYNET, which allows multiple virtual processors on multiple system nodes to communicate with each other. Shared Nothing Architecture (MPP) - means that each vproc(Access Module Processors and Parsing Engines are Virtual processors) is responsible for its own portion of the database and do not share common components.each AMP manages its own dedicated memory space and the data on its own vdisk -- these are not shared with other AMPs. Each AMP uses system resources independently of the other AMPs so they can all work in parallel for high system performance overall A node is made up of various hardware and softwares A clique is a set of Teradata nodes that share a common set of disk arrays. Cabling a subset of nodes to the same disk arrays...

Data warehousing : Data warehousing is combining data from multiple and usually varied sources into one comprehensive and easily manipulated database. Common accessing systems of data warehousing include queries, analysis and reporting. Because data warehousing creates one database in the end, the number of sources can be anything you want it to be, provided that the system can handle the volume, of course. The final result, however, is homogeneous data , which can be more easily manipulated. Data warehousing is comprised of two primary tools: databases and hardware. In a data warehouse, there are multiple databases and data tables used to store information. These tables are related to each other through the use of common information or keys. The size of a data warehouse is limited by the storage capacity of the hardware. The hardware required for a data warehouse includes a server, hard drives, and processors. In most organizations, the data warehouse is accessible via the sh...