[ https://issues.apache.org/jira/browse/SPARK-39839?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jungtaek Lim reassigned SPARK-39839: ------------------------------------ Assignee: Kris Mok > Handle special case of null variable-length Decimal with non-zero > offsetAndSize in UnsafeRow structural integrity check > ----------------------------------------------------------------------------------------------------------------------- > > Key: SPARK-39839 > URL: https://issues.apache.org/jira/browse/SPARK-39839 > Project: Spark > Issue Type: Bug > Components: SQL > Affects Versions: 3.1.0, 3.2.0, 3.3.0 > Reporter: Kris Mok > Assignee: Kris Mok > Priority: Major > > The {{UnsafeRow}} structural integrity check in > {{UnsafeRowUtils.validateStructuralIntegrity}} is added in Spark 3.1.0. It’s > supposed to validate that a given {{UnsafeRow}} conforms to the format that > the {{UnsafeRowWriter}} would have produced. > Currently the check expects all fields that are marked as null should also > have its field (i.e. the fixed-length part) set to all zeros. It needs to be > updated to handle a special case for variable-length {{{}Decimal{}}}s, where > the {{UnsafeRowWriter}} may mark a field as null but also leave the > fixed-length part of the field as {{OffsetAndSize(offset=current_offset, > size=0)}}. This may happen when the {{Decimal}} being written is either a > real {{null}} or has overflowed the specified precision. > Logic in {{UnsafeRowWriter}}: > in general: > {code:scala} > public void setNullAt(int ordinal) { > BitSetMethods.set(getBuffer(), startingOffset, ordinal); // set null bit > write(ordinal, 0L); // also zero out > the fixed-length field > } {code} > special case for {{DecimalType}}: > {code:scala} > // Make sure Decimal object has the same scale as DecimalType. > // Note that we may pass in null Decimal object to set null for it. > if (input == null || !input.changePrecision(precision, scale)) { > BitSetMethods.set(getBuffer(), startingOffset, ordinal); // set null > bit > // keep the offset for future update > setOffsetAndSize(ordinal, 0); // doesn't > zero out the fixed-length field > } {code} > The special case is introduced to allow all {{DecimalType}}s (including both > fixed-length and variable-length ones) to be mutable – thus need to leave > space for the variable-length field even if it’s currently null. > Note that this special case in {{UnsafeRowWriter}} has been there since Spark > 1.6.0, where as the integrity check was added in Spark 3.1.0. The check was > originally added for Structured Streaming’s checkpoint evolution validation, > so that a newer version of Spark can check whether or not an older checkpoint > file for Structured Streaming queries can be supported, and/or if the > contents of the checkpoint file is corrupted. -- This message was sent by Atlassian Jira (v8.20.10#820010) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org