[SPARK-33354] New explicit cast syntax rules in ANSI mode

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.0
• Fix Version/s: 3.1.0
• Component/s: SQL
• Epic Link: ANSI SQL compliance
• Assignee: Gengliang Wang
• Reporter: Gengliang Wang
• Created: 05/Nov/20 07:46
• Updated: 11/Apr/22 12:49
• Resolved: 19/Nov/20 00:24

Description

In section 6.13 of the ANSI SQL standard, there are syntax rules for valid combinations of the source and target data types.
To make Spark's ANSI mode more ANSI SQL Compatible，I propose to disallow the following casting in ANSI mode:

TimeStamp <=> Boolean
Date <=> Boolean
Numeric <=> Timestamp
Numeric <=> Date
Numeric <=> Binary
String <=> Array
String <=> Map
String <=> Struct

The following castings are considered invalid in ANSI SQL standard, but they are quite straight forward. Let's Allow them for now

Numeric <=> Boolean
String <=> Boolean
String <=> Binary

Issue Links

• is related to: SPARK-38860 ANSI enhancements in Spark 3.3
• links to: [Github] Pull Request #30260 (gengliangwang)
• links to: [Github] Pull Request #30260 (gengliangwang)
• links to: [Github] Pull Request #31180 (gengliangwang)
• links to: [Github] Pull Request #31523 (gengliangwang)