Account strings are an optional method of controlling the granularity of resource accumulations reported in the DBC.Acctg table. Account strings allow the collection of CPU and I/O that is reported in DBC.Acctg to be grouped by application, time of day, and priority. Variable substitution parameters included in the account string will be resolved at execution time.
A secondary use of account strings is to direct the classification of a request to a default Timeshare workload in TASM or TIWM. This classification will be effective only in cases where normal classification processes do not match the request to a user-defined workload.
If you use account strings, Teradata recommends that you devise an account system and then identify the accounts required for various groups in the user community before attempting to specify account information in user profiles. An account string is limited to 128 characters.
Account strings should follow this format:
|Account String Variables|
|$W00||Optional. For compatibility with previous releases of Advanced SQL Engine, you can classify a request to a Timeshare workload. If a request can be classified into a TASM workload and also has $W00 in the account string, the TASM workload classification takes precedence. If there are no workloads defined or if the request does not fit into an existing workload, TASM uses these characters to determine which Timeshare tier priority level applies to the workload.
Specify one of the following instead of $W00:
The default is $M00.
This default classification based on the starting characters in the account string will occur only if the request fails to classify to any other defined workload. This default classification exists to be backward-compatible with older versions of software and to help users transition easily to SLES 11 priority management. Teradata recommends that users of current software rely upon normal TASM/TIWM workload classification rather than this default approach.
|MSI||The application/workload name.
Recommendation: You can use the 3 characters of the application/workload name to differentiate accounts and to provide an abbreviated description of the account function. For example, a department, such as finance (FIN) or marketing (MKT).
|R||A one-character workload identifier. For example:
|Account String Expansion (ASE) Variables
Advanced SQL Engine tags the session with information specified by the ASE variables for later use in management of database sessions. Each ASE variable expands to the number of characters needed to express the related information. The string limit is enforced against the expanded form.
Specification of the ASE variables shown below is optional, but recommended. Other variables are available. For more information, see Logging Resource Usage Data with Account String Variables.
|&D||The ampersand (&) designates an account string expansion (ASE) variable. Advanced SQL Engine automatically replaces these variables with actual values upon opening the session. You can use either or both of the following:
Teradata no longer recommends using the &S (session) variable.