korlov42 commented on a change in pull request #8456:
URL: https://github.com/apache/ignite/pull/8456#discussion_r530894211
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File path:
modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/metadata/IgniteMdRowCount.java
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@@ -47,6 +48,63 @@
return joinRowCount(mq, rel);
}
+ /** */
+ public Double getRowCount(IgniteCorrelatedNestedLoopJoin rel,
RelMetadataQuery mq) {
+ if (!rel.getJoinType().projectsRight()) {
+ // Create a RexNode representing the selectivity of the
+ // semijoin filter and pass it to getSelectivity
+ RexNode semiJoinSelectivity =
+ RelMdUtil.makeSemiJoinSelectivityRexNode(mq, rel);
+
+ return multiply(mq.getSelectivity(rel.getLeft(),
semiJoinSelectivity),
+ mq.getRowCount(rel.getLeft()));
+ }
+
+ // Row count estimates of 0 will be rounded up to 1.
+ // So, use maxRowCount where the product is very small.
+ final Double left = mq.getRowCount(rel.getLeft());
+ final Double right = mq.getRowCount(rel.getRight());
+
+ if (left == null || right == null)
+ return null;
+
+ if (left <= 1D || right <= 1D) {
+ Double max = mq.getMaxRowCount(rel);
+ if (max != null && max <= 1D)
+ return max;
+ }
+
+ JoinInfo joinInfo = rel.analyzeCondition();
+
+ ImmutableIntList leftKeys = joinInfo.leftKeys;
+ ImmutableIntList rightKeys = joinInfo.rightKeys;
+
+ if (F.isEmpty(leftKeys) || F.isEmpty(rightKeys)) {
+ if (F.isEmpty(leftKeys))
+ return left * right;
+ else
+ return left * right * mq.getSelectivity(rel,
rel.getCondition());
+ }
+
Review comment:
because rel.estimateRowCount(mq) uses this method to estimate row count
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