Skip to main content

Posts

Showing posts from September, 2010

PE - Parsing Engine

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 pertinent AMPs, and 2) perf

AMP

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

Vprocs

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

BYNET

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

Teradata Architecture

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

Datawarehousing Concepts

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