Rules and Restrictions for Anchor Point Expansion of the EXPAND ON Clause - Teradata VantageCloud Lake

Lake - Working with SQL
Deployment
VantageCloud
Edition
Lake
Product
Teradata VantageCloud Lake
Release Number
Published
February 2025
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en-US
ft:lastEdition
2025-11-21
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jbe1714339405530
The following cases are possible with Anchor Point Expansion when the expansion interval is longer than the granularity of the element type of the expand expression:
  • There is no single anchor point in the expansion period.

    For example, if the expansion is by MONDAY and the expansion period is PERIOD(DATE '2007-08-14', DATE '2007-08-17'), then the expansion period starts on Tuesday and ends on Friday in the same week.

    The input row does not produce any expanded rows in the expanded result.

  • The beginning bound of the expansion period is not aligned to an anchor point and its duration is longer than the expansion interval.

    The expanded row set does not have a row corresponding to the beginning bound of the expansion period.

    For example, if the expansion is by MONDAY and the expansion period is PERIOD(DATE '2007-08-15', DATE '2007-08-25'), the expanded result contains only one point, which is DATE '2007-08-20'.

  • The beginning bound of the expansion period is aligned with an anchor point.

    The expanded rows contain a row with the beginning bound of the expansion period.

    For example, if the expansion is by MONDAY and the expansion period is PERIOD(DATE '2007-08-20', DATE '2007-08-25'), then the last expanded row contains DATE '2007-08-20'.

The expanded rows correspond to the anchor points (the BEGIN points of an anchor period) within the expansion period.