[ https://issues.apache.org/jira/browse/SPARK-25206?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Xiao Li updated SPARK-25206: ---------------------------- Target Version/s: 2.3.2, 2.4.0 (was: 2.3.2) > wrong records are returned when Hive metastore schema and parquet schema are > in different letter cases > ------------------------------------------------------------------------------------------------------ > > Key: SPARK-25206 > URL: https://issues.apache.org/jira/browse/SPARK-25206 > Project: Spark > Issue Type: Bug > Components: SQL > Affects Versions: 2.2.2, 2.3.1 > Reporter: yucai > Priority: Blocker > Labels: Parquet, correctness > Attachments: image-2018-08-24-18-05-23-485.png, > image-2018-08-24-22-33-03-231.png, image-2018-08-24-22-34-11-539.png, > image-2018-08-24-22-46-05-346.png, image-2018-08-25-09-54-53-219.png, > image-2018-08-25-10-04-21-901.png, pr22183.png > > > In current Spark 2.3.1, below query returns wrong data silently. > {code:java} > spark.range(10).write.parquet("/tmp/data") > sql("DROP TABLE t") > sql("CREATE TABLE t (ID LONG) USING parquet LOCATION '/tmp/data'") > scala> sql("select * from t where id > 0").show > +---+ > | ID| > +---+ > +---+ > {code} > > *Root Cause* > After deep dive, it has two issues, both are related to different letter > cases between Hive metastore schema and parquet schema. > 1. Wrong column is pushdown. > Spark pushdowns FilterApi.gt(intColumn("{color:#ff0000}ID{color}"), 0: > Integer) into parquet, but {color:#ff0000}ID{color} does not exist in > /tmp/data (parquet is case sensitive, it has {color:#ff0000}id{color} > actually). > So no records are returned. > Since SPARK-24716, Spark uses Parquet schema instead of Hive metastore schema > to do the pushdown, perfect for this issue. > 2. Spark SQL returns NULL for a column whose Hive metastore schema and > Parquet schema are in different letter cases, even spark.sql.caseSensitive > set to false. > SPARK-25132 addressed this issue already. > > The biggest difference is, in Spark 2.1, user will get Exception for the same > query: > {code:java} > Caused by: java.lang.IllegalArgumentException: Column [ID] was not found in > schema!{code} > So they will know the issue and fix the query. > But in Spark 2.3, user will get the wrong results sliently. > > To make the above query work, we need both SPARK-25132 and -SPARK-24716.- > > [~yumwang] , [~cloud_fan], [~smilegator], any thoughts? Should we backport it? -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org