[SPARK-30826] LIKE returns wrong result from external table using parquet

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.2, 2.1.3, 2.2.3, 2.3.4, 2.4.5, 3.0.0
• Fix Version/s: 2.4.6, 3.0.0
• Component/s: SQL
• Labels: correctness
• Assignee: Max Gekk
• Reporter: Max Gekk
• Created: 14/Feb/20 06:24
• Updated: 24/Feb/20 22:35
• Resolved: 15/Feb/20 12:13

Description

1. Write a parquet file with a column in upper case:

   Seq("42").toDF("COL").write.parquet(path)
   

2. Create an external table on top of the written parquet files with a column in lower case

   CREATE TABLE t1 (col STRING)
   USING parquet
   OPTIONS (path '$path')
   

3. Read the table using LIKE

   SELECT * FROM t1 WHERE col LIKE '4%'
   

   It returns empty set but must be one row with 42.

Issue Links

• links to: GitHub Pull Request #27574