Sessions Defined | Teradata Vantage - Sessions Defined - Analytics Database - Teradata Vantage

Database Administration

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-11-03
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lifecycle
latest
Product Category
Teradata Vantageā„¢

A session is a logical connection between the user and Analytics Database. A session permits a user to submit one transaction at a time and receive one response at a time, and the current session can have only one transaction outstanding at any time. A user may communicate through one or more active sessions concurrently.

A session is explicitly logged on and off from Analytics Database and is established when the Analytics Database server accepts the logon string of the user. When a session is logged off, the system discards the user-session identification and does not accept additional Teradata SQL statements from that session.

Request and Response Messages

When a session logs on, Analytics Database communicates with the host through request and response messages containing parcels of information. The maximum request message size is 7 MB. The maximum response message size is 16 MB.

How Request Parcels Are Handled

To access Analytics Database from a mainframe client, the user or application program logs on through a Teradata client interface product and submits a request. The request is processed by the interface and directed to a TDP.

Each request is handled as follows:

  • In a mainframe environment, mainframe CLIv2 builds the request parcel and sends it to the TDP, which sends it through the mainframe connection to the PE associated with that TDP.
  • In a network environment, the client interface product (such as CLIv2 or the Teradata JDBC Driver) builds the request parcel and sends it over the network to the gateway. The gateway sends the parcel to the PE for the session, which may or may not reside on the same node as the gateway.

Response Parcels

The result of a query or a status becomes a returned answer set. The PE turns the answer sets for a request into one or more response parcels and returns them to:
  • The TDP, in a mainframe environment. The TDP and mainframe CLIv2 returns it to the client utility or program.
  • The gateway, in a network environment. The gateway sends it to the client interface product (such as CLIv2 or the Teradata ODBC Driver). The client interface product returns the response to the client utility or program.