SQL HELP and SHOW Statements | Temporal Table Support | Teradata Vantage - 17.05 - SQL HELP and SHOW Statements - Teradata Database

Teradata Vantage™ - Temporal Table Support

Advanced SQL Engine
Teradata Database
June 2020
Programming Reference
HELP and SHOW statements display information that is relevant to temporal tables:
  • HELP COLUMN output includes a Temporal Column field that displays V, T, R, or N, to indicate a valid-time, transaction-time, temporal relationship constraint, or nontemporal column, respectively.
  • HELP COLUMN also includes fields named Current ValidTime Unique, Sequenced ValidTime Unique, NonSequenced ValidTime Unique, and Current TransactionTime Unique, which indicate the type of primary key or unique temporal constraint, if any, that is defined on the column. The values of these fields can be Y or N.
  • HELP CONSTRAINT has a Type field that shows information about named constraints, including temporal constraints.
  • HELP SESSION includes a Temporal Qualifier field that shows information about temporal session attributes.
  • HELP TRIGGER includes ValidTime Type and TransactionTime Type fields that display C, S, N, or T to indicate trigger types that are current, sequenced, nonsequenced, or nontemporal, respectively. If there is no time dimension defined on the trigger, these fields are NULL.
  • SHOW TABLE indicates valid-time and transaction-time columns, and shows temporal primary key and unique constraint definitions.
  • SHOW JOIN INDEX shows the temporal qualifier associated with a join index created on a temporal table, which is the temporal qualifier associated with the SELECT statement that created the join index.