Leonard Xu created FLINK-20405: ---------------------------------- Summary: The LAG function in over window is not implements correctly Key: FLINK-20405 URL: https://issues.apache.org/jira/browse/FLINK-20405 Project: Flink Issue Type: Bug Components: Table SQL / Runtime Affects Versions: 1.12.0 Reporter: Leonard Xu
For LAG(input, offset, default) function in over window, it always return current row's input no matter how the offset is set. After see the codegen code of the function, I think the implementation is not correct and need to correct. {code:java} // the offset and default value is never used public UnboundedOverAggregateHelper$24(java.lang.Object[] references) throws Exception { constant$14 = ((int) 1); constant$14isNull = false; constant$15 = ((org.apache.flink.table.data.binary.BinaryStringData) str$13); constant$15isNull = false; typeSerializer$19 = (((org.apache.flink.table.runtime.typeutils.StringDataSerializer) references[0])); } public void accumulate(org.apache.flink.table.data.RowData accInput) throws Exception { org.apache.flink.table.data.binary.BinaryStringData field$21; boolean isNull$21; org.apache.flink.table.data.binary.BinaryStringData field$22; isNull$21 = accInput.isNullAt(2); field$21 = org.apache.flink.table.data.binary.BinaryStringData.EMPTY_UTF8; if (!isNull$21) { field$21 = ((org.apache.flink.table.data.binary.BinaryStringData) accInput.getString(2)); } field$22 = field$21; if (!isNull$21) { field$22 = (org.apache.flink.table.data.binary.BinaryStringData) (typeSerializer$19.copy(field$22)); } if (agg0_leadlag != field$22) { agg0_leadlag = ((org.apache.flink.table.data.binary.BinaryStringData) typeSerializer$19.copy(field$22)); } ; agg0_leadlagIsNull = isNull$21; } {code} The question comes from user mail list[1] [1] http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/FlinkSQL-kafka-gt-dedup-gt-kafka-td39335.html -- This message was sent by Atlassian Jira (v8.3.4#803005)