[ https://issues.apache.org/jira/browse/SPARK-27089?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Marco Gaido resolved SPARK-27089. --------------------------------- Resolution: Information Provided > Loss of precision during decimal division > ----------------------------------------- > > Key: SPARK-27089 > URL: https://issues.apache.org/jira/browse/SPARK-27089 > Project: Spark > Issue Type: Bug > Components: SQL > Affects Versions: 2.3.0, 2.4.0 > Reporter: ylo0ztlmtusq > Priority: Major > > Spark looses decimal places when dividing decimal numbers. > > Expected behavior (In Spark 2.2.3 or before) > > {code:java} > scala> val sql = """select cast(cast(3 as decimal(38,14)) / cast(9 as > decimal(38,14)) as decimal(38,14)) val""" > sql: String = select cast(cast(3 as decimal(38,14)) / cast(9 as > decimal(38,14)) as decimal(38,14)) val > scala> spark.sql(sql).show > 19/03/07 21:23:51 WARN ObjectStore: Failed to get database global_temp, > returning NoSuchObjectException > +----------------+ > | val| > +----------------+ > |0.33333333333333| > +----------------+ > {code} > > Current behavior (In Spark 2.3.2 and later) > > {code:java} > scala> val sql = """select cast(cast(3 as decimal(38,14)) / cast(9 as > decimal(38,14)) as decimal(38,14)) val""" > sql: String = select cast(cast(3 as decimal(38,14)) / cast(9 as > decimal(38,14)) as decimal(38,14)) val > scala> spark.sql(sql).show > +----------------+ > | val| > +----------------+ > |0.33333300000000| > +----------------+ > {code} > > Seems to caused by {{promote_precision(38, 6) }} > > {code:java} > scala> spark.sql(sql).explain(true) > == Parsed Logical Plan == > Project [cast((cast(3 as decimal(38,14)) / cast(9 as decimal(38,14))) as > decimal(38,14)) AS val#20] > +- OneRowRelation > == Analyzed Logical Plan == > val: decimal(38,14) > Project [cast(CheckOverflow((promote_precision(cast(cast(3 as decimal(38,14)) > as decimal(38,14))) / promote_precision(cast(cast(9 as decimal(38,14)) as > decimal(38,14)))), DecimalType(38,6)) as decimal(38,14)) AS val#20] > +- OneRowRelation > == Optimized Logical Plan == > Project [0.33333300000000 AS val#20] > +- OneRowRelation > == Physical Plan == > *(1) Project [0.33333300000000 AS val#20] > +- Scan OneRowRelation[] > {code} > > Source https://stackoverflow.com/q/55046492 -- 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