Restrictions and Usage Rules - Teradata Database

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Restrictions and Usage Rules

Below are known requirements that could influence the standard formats of ASE:

  • Account strings cannot exceed 128 characters and must be able to accommodate any Performance Group name.
  • Be aware that the account string character count includes:
  • Separation characters, such as colons (:) in time fields and slashes (/) in dates. If a string consists of all the ASE variables, the result is 32 characters long. If an account string exceeds the character limit, characters to the right of the limit are truncated.
  • Performance group names.
  • You can intersperse ASE variables with literals, subject to the constraints of length and of position relative to performance group controls.
  • To the greatest extent possible and appropriate, request level usage detail should be captured. If DBQL is enabled, however, ASE becomes less important as a mechanism for enabling request level usage detail since DBQL can capture usage for queries.
  • Recommendation for account string setup: $H1$WXYZ&S&D&H, where:

    $H1$ = Performance Group PG

    WXYZ = Work Group Identifier

    &S&D&H = ASE Variables for session, date, and hour

  • Where possible, associate usage detail to higher-level aggregation for production batch processing, such as to the job or job step level.
  • For requests requiring short response time, the account string setup should not materially impact the performance of the request.
  • Provide the detailed information necessary to effectively manage the system. When consistently adhered to, the proper information will be captured to facilitate a wide variety of analyses and produce a set of standard metrics by which to measure the system.
  • When combining ASE variables, keep the following in mind:
  • You can use multiple ASE variables in any order in the account string following the first ASE variable.
  • The account string limit is 128-characters.
  • Although it is perfectly legal to combine the &H and &T options, the information collected is redundant.
  • If you specify &H or &T without &D, statistics collected on one day at one time are combined with statistics collected on other days at that same time.