[SPARK-34727] Difference in results of casting float to timestamp

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.0
• Fix Version/s: 3.1.2, 3.2.0
• Component/s: SQL
• Labels: correctness
• Assignee: Max Gekk
• Reporter: Max Gekk
• Created: 12/Mar/21 12:12
• Updated: 12/Dec/22 18:11
• Resolved: 14/Mar/21 02:30

Description

The code below portraits the issue:

spark-sql> CREATE TEMP VIEW v1 AS SELECT 16777215.0f AS f;
spark-sql> SELECT * FROM v1;
1.6777215E7
spark-sql> SELECT CAST(f AS TIMESTAMP) FROM v1;
1970-07-14 07:20:15
spark-sql> CACHE TABLE v1;
spark-sql> SELECT * FROM v1;
1.6777215E7
spark-sql> SELECT CAST(f AS TIMESTAMP) FROM v1;
1970-07-14 07:20:14.951424

The result from the cached view 1970-07-14 07:20:14.951424 is different from un-cached view 1970-07-14 07:20:15.

Issue Links

• is related to: SPARK-34737 Discrepancy between TIMESTAMP_SECONDS and cast from float
• links to: [Github] Pull Request #31819 (MaxGekk)
• links to: [Github] Pull Request #31819 (MaxGekk)