Overlaps (disambiguation)

1. Some variants
2. ⚡Zero-length periods don’t overlap with start of other period.
   (DATE'2026-01-07', DATE'2026-01-07') OVERLAPS (DATE'2026-01-07', DATE'2026-01-31')
   The standard requires this to evaluate to true while this system makes it false
   ⚡Single null values construct zero-length periods.
   NOT (DATE'2026-01-03', null) OVERLAPS (DATE'2026-01-07', DATE'2026-01-31')
   The standard requires this to evaluate to unknown but this system gives true
   ⚡Fails if one side consists of two null values.
   (null, null) OVERLAPS (DATE'2026-01-07', DATE'2026-01-31')
   The standard requires this to evaluate to unknown but this system gives an error • Some variants
3. Without keyword for: PERIOD FOR BUSINESS_TIME (…)
4. Using the btree_gist extension and a range: BUSINESS_TIME tsrange GENERATED ALWAYS AS (tsrange(start_ts, end_ts)) STORED • Functionality available with exclusion constraints

Related

• Standard Features

  • F053, “OVERLAPS predicate”

    Overlaps on row-values: Symmetric, potentially zero-length, null is unknown

  • T502, “Period predicates”: overlaps, contains, precedes, succeeds

    On application-time periods, never zero-length, no null.

  • T181, “Application-time period tables”

• Non-Standard Features

  • && on PostgreSQL range types: Range types treat null as open end.