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https://issues.apache.org/jira/browse/CALCITE-3287?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Hong Shen updated CALCITE-3287:
-------------------------------
Description:
when I read the RelMdRowCount.java, I found that union's getRowCount has not
consider 'union all', while in Union.estimateRowCount has. can any body tell me
why？
{code}
RelMdRowCount.java
public Double getRowCount(Union rel, RelMetadataQuery mq) {
double rowCount = 0.0;
for (RelNode input : rel.getInputs()) {
Double partialRowCount = mq.getRowCount(input);
if (partialRowCount == null) {
return null;
}
rowCount += partialRowCount;
}
return rowCount;
}
Union.java
@Override public double estimateRowCount(RelMetadataQuery mq) {
double dRows = RelMdUtil.getUnionAllRowCount(mq, this);
if (!all) {
dRows *= 0.5;
}
return dRows;
}
{code}
was:
when I read the RelMdRowCount.java, I found that union's getRowCount has not
consider 'union all', while in Union.estimateRowCount has. can any body tell me
why？
> Union's getRowCount in RelMdRowCount has not consider 'union all'
> -----------------------------------------------------------------
>
> Key: CALCITE-3287
> URL: https://issues.apache.org/jira/browse/CALCITE-3287
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Hong Shen
> Priority: Minor
>
> when I read the RelMdRowCount.java, I found that union's getRowCount has not
> consider 'union all', while in Union.estimateRowCount has. can any body tell
> me why？
> {code}
> RelMdRowCount.java
> public Double getRowCount(Union rel, RelMetadataQuery mq) {
> double rowCount = 0.0;
> for (RelNode input : rel.getInputs()) {
> Double partialRowCount = mq.getRowCount(input);
> if (partialRowCount == null) {
> return null;
> }
> rowCount += partialRowCount;
> }
> return rowCount;
> }
> Union.java
> @Override public double estimateRowCount(RelMetadataQuery mq) {
> double dRows = RelMdUtil.getUnionAllRowCount(mq, this);
> if (!all) {
> dRows *= 0.5;
> }
> return dRows;
> }
> {code}
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