zstan commented on code in PR #13389:
URL: https://github.com/apache/ignite/pull/13389#discussion_r3644576148
##########
modules/calcite/src/main/java/org/apache/ignite/internal/processors/query/calcite/metadata/IgniteMdRowCount.java:
##########
@@ -72,48 +92,261 @@ public class IgniteMdRowCount extends RelMdRowCount {
mq.getRowCount(rel.getLeft()));
}
+ JoinInfo joinInfo = rel.analyzeCondition();
+
+ if (joinInfo.pairs().isEmpty()) {
+ // Fall-back to calcite's implementation.
+ return RelMdUtil.getJoinRowCount(mq, rel, rel.getCondition());
+ }
+
// 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());
+ final Double leftRowCnt = mq.getRowCount(rel.getLeft());
+ final Double rightRowCnt = mq.getRowCount(rel.getRight());
- if (left == null || right == null)
+ if (leftRowCnt == null || rightRowCnt == null)
return null;
- if (left <= 1D || right <= 1D) {
+ if (leftRowCnt <= 1D || rightRowCnt <= 1D) {
Double max = mq.getMaxRowCount(rel);
if (max != null && max <= 1D)
return max;
}
- JoinInfo joinInfo = rel.analyzeCondition();
+ Map<Integer, KeyColumnOrigin> columnsFromLeft = resolveOrigins(mq,
rel.getLeft(), joinInfo.leftKeys);
+ Map<Integer, KeyColumnOrigin> columnsFromRight = resolveOrigins(mq,
rel.getRight(), joinInfo.rightKeys);
+
+ if (columnsFromLeft.isEmpty() || columnsFromRight.isEmpty())
+ return crudeEstimation(mq, joinInfo, rel, leftRowCnt, rightRowCnt);
+
+ Map<TablesPair, JoinContext> joinCtxts = new HashMap<>();
+ for (IntPair joinKeys : joinInfo.pairs()) {
+ KeyColumnOrigin leftKey = columnsFromLeft.get(joinKeys.source);
+ KeyColumnOrigin rightKey = columnsFromRight.get(joinKeys.target);
+
+ if (leftKey == null || rightKey == null) {
+ continue;
+ }
+
+ joinCtxts.computeIfAbsent(
+ new TablesPair(
+ leftKey.origin.getOriginTable(),
+ rightKey.origin.getOriginTable()
+ ),
+ key -> {
+ IgniteTable leftTable = key.left.unwrap(IgniteTable.class);
+ IgniteTable rightTable =
key.right.unwrap(IgniteTable.class);
+
+ assert leftTable != null && rightTable != null;
+
+ int leftPkSize = leftTable.distribution().getKeys().size();
+ int rightPkSize =
rightTable.distribution().getKeys().size();
+
+ return new JoinContext(leftPkSize, rightPkSize);
+ }
+ ).countKeys(leftKey, rightKey);
+ }
+
+ if (joinCtxts.isEmpty()) {
+ // Fall-back to calcite's implementation.
+ return RelMdUtil.getJoinRowCount(mq, rel, rel.getCondition());
+ }
+
+ Iterator<JoinContext> it = joinCtxts.values().iterator();
+ JoinContext joinCtx = it.next();
+ while (it.hasNext()) {
+ JoinContext nextCtx = it.next();
+ if (nextCtx.joinType().strength > joinCtx.joinType().strength) {
+ joinCtx = nextCtx;
+ }
+
+ if (joinCtx.joinType().strength ==
JoiningRelationType.PK_ON_PK.strength) {
+ break;
+ }
+ }
+
+ if (joinCtx.joinType() == JoiningRelationType.UNKNOWN) {
+ // Fall-back to calcite's implementation.
+ return RelMdUtil.getJoinRowCount(mq, rel, rel.getCondition());
+ }
+
+ double postFiltrationAdjustment = 1.0;
+
+ switch (rel.getJoinType()) {
+ case INNER:
+ case SEMI:
+ // Extra join keys as well as non-equi conditions serves as
post-filtration,
+ // therefore we need to adjust final result with a little
factor.
+ if (joinCtxts.size() != 1 || !joinInfo.isEqui())
+ postFiltrationAdjustment = NON_EQUI_COEFF;
+
+ break;
+ default:
+ break;
+ }
+
+ double baseRowCnt = 0.0;
+ Double percentageAdjustment = null;
+ if (joinCtx.joinType() == JoiningRelationType.PK_ON_PK) {
+ postFiltrationAdjustment = EQUI_COEFF;
+
+ if (rel.getJoinType() == JoinRelType.INNER || rel.getJoinType() ==
JoinRelType.SEMI) {
+ // Assume we have two fact tables SALES and RETURNS sharing
the same primary key. Every item
+ // can be sold, but only items which were sold can be returned
back, therefore
+ // size(SALES) > size(RETURNS). When joining SALES on RETURNS
by primary key, the estimated
+ // result size will be the same as the size of the smallest
table (RETURNS in this case),
+ // adjusted by the percentage of rows of the biggest table
(SALES in this case; percentage
+ // adjustment is required to account for predicates pushed
down to the table, e.g. we are
+ // interested in returns of items with certain category)
+ if (leftRowCnt > rightRowCnt) {
+ baseRowCnt = rightRowCnt;
+ percentageAdjustment =
mq.getPercentageOriginalRows(rel.getLeft());
+ }
+ else {
+ baseRowCnt = leftRowCnt;
+ percentageAdjustment =
mq.getPercentageOriginalRows(rel.getRight());
+ }
+ }
+ else if (rel.getJoinType() == JoinRelType.LEFT) {
+ baseRowCnt = leftRowCnt;
+ }
+ else if (rel.getJoinType() == JoinRelType.RIGHT) {
+ baseRowCnt = rightRowCnt;
+ }
+ else if (rel.getJoinType() == JoinRelType.FULL) {
+ Double selectivity = mq.getSelectivity(rel,
rel.getCondition());
+
+ // Fall-back to calcite's implementation.
+ if (selectivity == null) {
+ return RelMdUtil.getJoinRowCount(mq, rel,
rel.getCondition());
+ }
+
+ baseRowCnt = rightRowCnt + leftRowCnt;
+ percentageAdjustment = 1.0 - selectivity;
+ }
+ }
+ else if (joinCtx.joinType() == JoiningRelationType.FK_ON_PK) {
+ // For foreign key joins the base table is the one which is joined
by non-primary key columns.
+ if (rel.getJoinType() == JoinRelType.INNER || rel.getJoinType() ==
JoinRelType.SEMI) {
+ baseRowCnt = leftRowCnt;
+ // Need to adopt: IGNITE-23969, after it become possible to
change into: mq.getPercentageOriginalRows(rel.getRight());
+ percentageAdjustment = FK_WITH_PK_COEFF;
+ }
+ else if (rel.getJoinType() == JoinRelType.LEFT ||
rel.getJoinType() == JoinRelType.RIGHT) {
+ baseRowCnt = leftRowCnt;
+ }
+ else if (rel.getJoinType() == JoinRelType.FULL) {
+ Double selectivity = mq.getSelectivity(rel,
rel.getCondition());
+
+ // Fall-back to calcite's implementation.
+ if (selectivity == null) {
+ return RelMdUtil.getJoinRowCount(mq, rel,
rel.getCondition());
+ }
+
+ baseRowCnt = rightRowCnt + leftRowCnt;
+ percentageAdjustment = 1.0 - selectivity;
+ }
+ }
+ else { // PK_ON_FK
+ if (rel.getJoinType() == JoinRelType.INNER || rel.getJoinType() ==
JoinRelType.SEMI) {
+ baseRowCnt = rightRowCnt;
+ percentageAdjustment =
mq.getPercentageOriginalRows(rel.getLeft());
+ }
+ else if (rel.getJoinType() == JoinRelType.RIGHT ||
rel.getJoinType() == JoinRelType.LEFT) {
+ baseRowCnt = rightRowCnt;
+ }
+ else if (rel.getJoinType() == JoinRelType.FULL) {
+ Double selectivity = mq.getSelectivity(rel,
rel.getCondition());
+
+ // Fall-back to calcite's implementation.
+ if (selectivity == null) {
+ return RelMdUtil.getJoinRowCount(mq, rel,
rel.getCondition());
+ }
+
+ baseRowCnt = rightRowCnt + leftRowCnt;
+ percentageAdjustment = 1.0 - selectivity;
+ }
+ }
+
+ if (percentageAdjustment == null) {
+ percentageAdjustment = 1.0; // No info, let's be conservative
+ }
+
+ return baseRowCnt * percentageAdjustment * postFiltrationAdjustment;
+ }
+
+ /** */
+ private static Map<Integer, KeyColumnOrigin>
resolveOrigins(RelMetadataQuery mq, RelNode joinShoulder, ImmutableIntList
keys) {
+ GridLeanMap<Integer, KeyColumnOrigin> origins = new GridLeanMap<>();
+
+ for (int i : keys) {
+ if (origins.containsKey(i)) {
+ continue;
+ }
+
+ RelColumnOrigin origin = mq.getColumnOrigin(joinShoulder, i);
+ if (origin == null) {
+ continue;
+ }
+ IgniteTable table =
origin.getOriginTable().unwrap(IgniteTable.class);
+ if (table == null || !table.distribution().function().affinity())
+ continue;
+
+ // Keys can relate to affinity not pk, just assumption here.
+ ImmutableIntList distKeys = table.distribution().getKeys();
Review Comment:
of course we need to have 'real pk' here, but fix it right now - seems too
huge.
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