[CALCITE-5290] Add DATE_TRUNC function consistent with Postgres

• Type: Bug
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Assignee: Guillaume Massé
• Reporter: Julian Hyde
• Created: 20/Sep/22 01:45
• Updated: 08/Aug/23 19:46

Description

Add DATE_TRUNC function consistent with Postgres. Per the specification, syntax is as follows:

DATE_TRUNC(<string>, <timestamp | date | time>)

It is a different (and more complex) specification than BigQuery's DATE_TRUNC (see CALCITE-5180), which has the following syntax:

DATE_TRUNC(<date>, <interval>)

Postgres DATE_TRUNC would be implemented after CALCITE-5155 and would allow user-defined time frames in the field argument.

Issue Links

• is related to: CALCITE-5180 Implement BigQuery functions for DATE, TIME, TIMESTAMP, DATETIME
• is related to: CALCITE-5155 Custom time frames
• is related to: CALCITE-5902 Add DATE_TRUNC function consistent with Apache Spark
• is related to: CALCITE-5447 Add DATE_TRUNC for BigQuery
• relates to: CALCITE-5269 Implement BigQuery TIME_TRUNC and TIMESTAMP_TRUNC functions