Teradata Architecture

The architecture of Teradata is a Massively Parallel processing architecture. The Teradata system has four components.

• Parsing Engine
• BYNET
• AMPs
• Disk

Based on the principal function of the Teradata system, the architecture can be categorized into two sections, such as:

1. Storage Architecture
2. Retrieval Architecture

Storage Architecture

The storage architecture consists of the above two components of the Teradata architecture. When the client runs queries to insert records, the Parsing engine sends the files to BYNET. BYNET retrieves the files and sends the row to the target AMP. AMP stores these records on its disks.

1. Parsing Engine

When a user fires an SQL query, it first gets connected to the Parsing Engine. The processes, such as planning and distributing the data to AMPS, are done here. It finds out the best optimal plan for query execution. Parsing Engine performs the following processes, such as:

• Parser: The Parser checks for the syntax, if true forward the query to Session Handler.
• Session Handler: It does all the security checks, such as checking of logging credentials and whether the user has permission to execute the query or not.
• Optimizer: It finds out the best possible and optimized plan to execute the query.
• Dispatcher: The Dispatcher forwards the query to the AMPs.

2. AMP

Access Module Processor is a virtual processor that connects to PE via BYNET. Each AMP has its disk and is allowed to read and write in its disk. This is called as 'SHARED NOTHING ARCHITECTURE'.

When the query is fired, then Teradata distributes the rows of a table on all the AMPs. The AMP executes any SQL requests in the following steps, such as:

1. Lock the table.
2. Execute the operation requested.
3. End the transaction.

Retrieval Architecture

This architecture section consists of reaming two components of the Teradata architecture. When the client runs queries to retrieve records, the Parsing engine sends a request to BYNET. BYNET sends the retrieval request to appropriate AMPs. Then AMPs search their disks in parallel and identify the required records and forwards to BYNET. BYNET sends the records to Parsing Engine, which in turn will send to the client.

1. BYNET

The BYNET acts as a channel between PE and AMPs. There are two BYNETs in Teradata 'BYNET 0' and 'BYNET 1'.

1. If one BYNET fails, the second one can take its place.
2. When data is large, both BYNETs can be made functional, which improves the communication between PE and AMPs, thus fastening the process.

2. Disk

Teradata offers a set of Virtual Disks for each AMP. The storage area of each AMP is called as Virtual Disk or Vdisk. Here are the following steps for executing the query, such as:

Step 1: The user raises the question which is sent to PE.

Step 2: PE checks the security and syntax, and finds out the best optimal plan to execute the query.

Step 3: The table rows are distributed on the AMP, and the data is retrieved from the disk.

Step 4: The AMP sends back the data through BYNET to PE.

Step 5: PE returns the data to the user.