The PE is the vproc that communicates with the client system on one side and with the AMPs (via the BYNET) on the other side.
Each PE executes the database software that manages sessions, decomposes SQL statements into steps, possibly in parallel, and returns the answer rows to the requesting client.
The PE software consists of the following elements.
|
Parsing Engine Elements |
Process |
|
Parser |
Decomposes SQL into relational data management processing steps. |
|
Optimizer |
Determines the most efficient path to access data. |
|
Generator |
Generates and packages steps. |
|
Dispatcher |
Receives processing steps from the parser and sends them to the appropriate AMPs via the BYNET. |
|
Monitors the completion of steps and handles errors encountered during processing. |
|
|
Session Control |
|