The following are the critical Teradata Components







AMP is vproc . vproc is nothing But collection of instructions, which performs a specific operation(or)Task

PE[Passing Engine]



Passing Engine

 It takes SQL Request and delivery SQL response


Session Control

Session is nothing but logical connection between user and Application. Passing Engine checks the authentication and authorization, if it’s valid, it does log in other wise log off


  • It checks syntactical Error
  • It checks symmetrical Error
  • It checks Existence of object

These core tutorials will help you to learn the Teradata Components. For an in-depth 

understanding and practical experience, explore Online Teradata Training.

Query Rewrite Mechanism

It writes the Query such away optimizer can understand easily



 IF The Query is Q7,it converts into Q2



It is important component in any database including Teradata

It provides execution plan for SQL Statement, so that it is going to be executed by database

Generally it usages the below information.

  • System configuration
  • Available parallel unit
  • Data Demographics, etc
  • Access plan
  • Join plan


It generated steps for plan provided


It performs and manager request and response, flow control(Taking Request, Response keeping in Queue  in delivery)


 Passing Engine Handle max 120 sessions at a time


It acts like” Message communication layer” between various components.



POINT - POINT-One message from PE To one AMP

MULIT CAST-One message from PE to Many AMPs

BROAD CAST- One message from PE to All AMPs



POINT- POINT-One message from One NODE to other NODE

MULIT CAST-One message from One NODE to Many NODE

BROAD CAST- One message from One NODE to All NODE


AMP[Access Module Processor]

Each AMP is responsible for managing a portion of MAIN DISK SPACE (VIRTUAL DISK)

This space not sharable by any other AMPs so we call architecture as shared nothing architecture.

Each AMP Operator independently resources

Each AMP contain database management sub system. If perform the below operations.

  • Performing DDL
  • Performing DML
  • Performing Joins
  • Performing Applying and Releasing locks
  • Performing Aggregate operation
  • Performing OLAP operation
  • Performing SORTING Operation etc.,


Max so task AMP TO perform at a time

Multiple AMP runs independently so high parallelism implement


VSS(Virtual Storage System):

It is available from teradata 13 onwards, basically design to manage a multi tier ware house

Teradata VSS Pools all of the cylinders with in CLIQUE’s DISK SPACE and allocates cylinders from storage pool.

It migrates frequently used data (Hot data) to FASTER DEVICES and less frequently used data (cold data)to SLOWER DEVICES.


Before Teradata VSS

a) AMPS know the physical location of cylinder which are address by DRIVE# (OR) CYLINDER#

b) Adjusting system AMPS integral number of drives per AMP

c) Adding storage requires an additional drive per AMP.


After TDV SS

a) AMPs don’t know the physical location of cylinder and it can be change, because of the cylinder in CLIQUE’s On effective in pool, that are managed by teradata virtual storage, virtual process.

b) Added drives are shared by all AMP’s

c) You can add a number of drives, This new Drive may have difference capacity are performance than those drives, which are already present in the system


Before Teradata Virtual storage




After  Teradata Virtual storage




Virtual Disk (or)VDISK



Collection of physical DISK (OR) Group of cylinder Arranged in Array position is called VDISK(or) virtual DISK

Traditionally this called as DISK Array (or) Array of DISK

After AMP performance operation, it is invokes the controller this store and manage the data across physical disk

This controller active array controller, the number of cylinders in an Array is called a RANK in the above Diagram the Rank is 3.(N-1)=4-1=3

  • MTDP-Micro Tera data Directory program
  • MOSI- Micro Operating system Independent
  • CA-Channel Application

Learn more about Teradata Interview Questions in this blog post.



For connection to teradata database system, we need to connection through either CHANNEL ATTACHED SYSTEM OR NETWORK ATTACHED SYSTEM


TDP(Teradata Directory Program)

If check the authentication is successfully, it creates a session and Log on

It balances multiple session [Create multiple session]


MTDP(Micro Tera data Directory Program)

It just like TDP cannot balances to sessions


CLI (CALL LEVEL Interface)

It is low level interface for request, response Blocking and un- Blocking.


MOSI (Micro operating system Independent)

It checks the plat form Independence of the operating system.

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