[DRILL-5756] CONVERT_FROM_JSON on a non-existent column throws NullPointerException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Storage - JSON
• Assignee: Unassigned
• Reporter: Vova Vysotskyi
• Created: 31/Aug/17 14:46
• Updated: 31/Aug/17 16:37

Description

Query

SELECT CONVERT_FROM(columns[1], 'JSON') as col1 FROM dfs.`file1.tbl`;

where file1.tbl is a file with single column (it has only columns[0]) returns error

Error: SYSTEM ERROR: NullPointerException

Fragment 0:0

[Error Id: 85b7fa7f-2049-4c8b-8c96-805af218f118 on node1:31010] (state=,code=0)

It should return single row with null value since CONVERT_FROM is executed on the column that does not exists.

Problem description
convert_fromJSON function considers only non-nullable VarCharHolder, but for this case, we receive NullableVarCharHolder which has a null value. So convert_fromJSON function that takes NullableVarCharHolder as an input parameter should be added.

cat file1.tbl
"{a:1}"

Issue Links

• is related to: DRILL-4824 Null maps / lists and non-provided state support for JSON fields. Numeric types promotion.