TERADATA Architecture can be very easily explained with the help of below points.
The first component is PE (Parsing Engine) It has below things:
Session Control > It checks for user authorization before processing any SQL queries. A PE can support upto 120 sessions.
Parser > It checks for the SQL syntax and user rights to access various database objects referred in the SQL query submitted by user.
Optimizer > It create a plan or execution steps to follow in order to perform actions on database objects as per SQL query submitted by user.
Dispatcher > It passes the execution steps to BYNET. Dispatcher also plays an important role by combining all the responses received and send it to user.
Next component is BYNET.
It is used for communication between PEs and AMPs (Access Module Processor).
There are two BYNETs available in any TERADATA environment: BYNET-0 & BYNET-1. Two BYNETs allows for continuos sending and receiving messages between PEs and AMPs.
Access Module Processor (AMP)
Next to BYNET, we have AMPs. AMPs can be considered as the worker in TERADATA Architecture.
Each AMP has its own dedicated VDISK (Virtual DISK) to which it queries and process the steps planned by Optimizer.
Virtual Disk (vDisk):
AMPs work only on their own VDISK and do not have access to other AMPs VDISK.
Once the AMP perform the steps, it send back response to PE via BYNET where all the responses from various AMPs is collected and sent back to user.
TERADATA is unique because of its parallel acrhitecture. So it is very important to understand the Teradata Architecture very well. The above diagram is a very basic illustration of Teradata Architecture and one must always remeber this. Understanding of architecture may help to understand how SQL Queries once submitted are processed by TERADATA.
The execution steps can be checked with the explain plan