PE and AMP setup

Database
Enthusiast

PE and AMP setup

Hi,

During the Teradata setup, how do we set up PE and AMP. In a ideal scenario, what is the number of PEs are setup and how many AMPs does PE is set to serve.

To be clear...Is there a ratio between the PE and AMPs..like a PE can handle 10 Amps ...Let us consider a small data mart with a few GB of space, and we have 10 PEs, so the max the system can handle is (10*10) Amps..

Thanks,
Arun
7 REPLIES
Senior Apprentice

Re: PE and AMP setup

A PE doesn't "serve" AMPs, it's "serving" sessions.
Thus there's no ratio between PEs and AMPs, typically you got 2 PEs per node and enough AMPs to keep your hardware (CPU & disks) busy.

Dieter
Enthusiast

Re: PE and AMP setup

Thanks for the reply...So the 2 PEs will be sending across the requests to all the amps in the node. Am i right...

Arun
Enthusiast

Re: PE and AMP setup

PEs can send requests to any or all of the AMPs in the system, including AMPs on other nodes.
Enthusiast

Re: PE and AMP setup

at a min 1 PE and at a Max 10 PE's can be there.
But generally Node has 2 PE's and number of Amps vary..
Enthusiast

Re: PE and AMP setup

How do teradata determine the # of AMPS per node.

Given a number of nodes - is there a thumb rule to get # amps ?

Senior Apprentice

Re: PE and AMP setup

The number of AMPs in the system is easy to get:

SELECT HASHAMP() + 1;

When you got access to dbc.Resusage you will find the number of AMPs for each node using:

SELECT DISTINCT NodeID, Vproc1 AS "#AMPs", Vproc2 AS "#PEs" 
FROM dbc.resusagespma
WHERE TheDate = CURRENT_DATE

Dieter

Teradata Employee

Re: PE and AMP setup

A Teradata machine is preconfigured when ordered by the customer's Teradata team.  The number of AMPs per node while generally not fixed is within a small range per node depending upon node model (for certain kinds of nodes, there may be 28, another model may have 44 amps per node, etc.). 

The PEs are configured to support the number of expected simultaneous sessions.  Each PE can support 120 sessions.  If you expect to support 500 simultaneous sessions, you will need at least 5 PEs (and you may want a couple of extra in case you have a node down or more sessions than expected.  For processing queries, PE's don't talk directly to amps but instead reduce each SQL query to a number of steps that are sent to the dispatcher which then sends each step, in the proper order to either the proper amp or amps in order to process the query.  The answer set is in the form of a spool file which read out by whatever tool the user used to submit the query. 

I hope that this answers you question,

Rick Sumner