Architecture

Teradata relies on three architectural components.

• Parsing Engine(PE) or Optimizer
• Access Module Processors(AMPs)
• BYNETs
• Disks

Teradata Architecture

Parsing Engine (PE)
The Parsing Engine (PE) is a component that interprets SQL requests, receives input records, and passes data. It sends the messages through the BYNET to the AMPs.

BYNETs
The BYNET act as message-passing layer. It decides which AMP should receive a message.

Access Module Processor (AMP)
The AMP is a virtual processor (vproc) designed to managing a portion of the entire database.
It performs all database management functions such as sorting, aggregating, and formatting data.
The AMP receives data from the PE, formats rows, and distributes them to the disk storage units it controls. The AMP also retrieves the rows requested by the Parsing Engine.

Disks
Disks are disk drives associated with an AMP that store the data rows.

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BYNET

The BYNET gets its name from the Banyan tree. The Banyan tree has the ability to continually plant new roots to grow forever. Likewise, the BYNET scales as the Teradata system grows in size.

All communication between PEs and AMPs is done via the BYNET.
When the PE dispatches the steps for the AMPs to perform, they are dispatched onto the BYNET.The messages are routed to the appropriate AMP(s).
Each AMP or PE can use one BYNET to retrieve communication and simultaneously accept messages using the other BYNET. Both BYNETs can be used to send a message or to receive a message!

BYNET

The BYNET has several unique features:

Scalable: As you add more nodes to the system, the overall network bandwidth scales linearly. This linear scalability means you can increase system size without performance penalty -- and sometimes even increase performance.

High performance: An MPP system typically has two BYNET networks (BYNET 0 and BYNET 1). Because both networks in a system are active, the system benefits from having full use of the aggregate bandwidth of both the networks.

Fault tolerant: Each network has multiple connection paths. If the BYNET detects an unusable path in either network, it will automatically reconfigure that network so all messages avoid the unusable path. Additionally, in the rare case that BYNET 0 cannot be reconfigured, hardware on BYNET 0 is disabled and messages are re-routed to BYNET 1.

Load balanced: Traffic is automatically and dynamically distributed between both BYNETs.

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AMP

The PE passes the PLAN to the AMPs over the BYNET. The AMPs then retrieve the rows they own from their disks and pass it back to the PE over the BYNET.

When a table is first created each AMP creates a table header on their disk. Even though the table is empty the AMPs at least know the table name, the columns in the table, and any indexes the table.

When the table is loaded each AMP receives rows for that table that they and only they own. They carefully place the rows inside data blocks where they can easily be retrieved.

Now each AMP will own their own Table Header for the table and they will also own data blocks where they place the rows for that table

AMP

Teradata took every table and spread the rows across all the AMPs in the system and the birth of parallel processing happened.

The first picture on the opposite page never happens. The second picture below that is exactly the design behind Teradata.

Teradata NEVER lays out data like this

Teradata lays out data like this!

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