englefly commented on code in PR #40654:
URL: https://github.com/apache/doris/pull/40654#discussion_r1753609665
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java:
##########
@@ -177,14 +181,27 @@ private static double
computeSelectivityForBuildSideWhenColStatsUnknown(Statisti
if (cond instanceof EqualTo) {
EqualTo equal = (EqualTo) cond;
if (equal.left() instanceof Slot && equal.right() instanceof
Slot) {
- ColumnStatistic buildColStats =
buildStats.findColumnStatistics(equal.left());
- if (buildColStats == null) {
- buildColStats =
buildStats.findColumnStatistics(equal.right());
+ Slot buildSideSlot = null;
+ if (buildStats.findColumnStatistics(equal.left()) != null)
{
+ buildSideSlot = (Slot) equal.left();
+ } else if (buildStats.findColumnStatistics(equal.right())
!= null) {
+ buildSideSlot = (Slot) equal.right();
}
- if (buildColStats != null) {
- double buildSel = Math.min(buildStats.getRowCount() /
buildColStats.count, 1.0);
- buildSel = Math.max(buildSel,
UNKNOWN_COL_STATS_FILTER_SEL_LOWER_BOUND);
- sel = Math.min(sel, buildSel);
+ // the processing is mainly for olap table since external
table rarely has column level statistics
Review Comment:
1. if this funciton does not work for external table, put this check at the
begining of this function.
2. It seems not good if the sel for external table is always 1
##########
fe/fe-core/src/main/java/org/apache/doris/statistics/ColumnStatisticBuilder.java:
##########
@@ -56,9 +56,24 @@ public ColumnStatisticBuilder(ColumnStatistic
columnStatistic) {
this.updatedTime = columnStatistic.updatedTime;
}
- public ColumnStatisticBuilder setCount(double count) {
+ // ATTENTION: DON'T USE FOLLOWING TWO DURING STATS DERIVING EXCEPT FOR
INITIALIZATION
+ public ColumnStatisticBuilder(double count) {
this.count = count;
- return this;
+ }
+
+ public ColumnStatisticBuilder(ColumnStatistic columnStatistic, double
count) {
Review Comment:
this constructor can be removed. the parameter columnStatistic is always
UNKNOWN.
It can be replaced by ColumnStatisticBuilder(count)
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java:
##########
@@ -403,8 +403,7 @@ private Statistics computeOlapScan(OlapScan olapScan) {
for (Slot slot : ((Relation) olapScan).getOutput()) {
if (derivedStats.findColumnStatistics(slot) == null) {
derivedStats.addColumnStats(slot,
- new
ColumnStatisticBuilder(ColumnStatistic.UNKNOWN)
-
.setCount(derivedRowCount).build());
+ new
ColumnStatisticBuilder(ColumnStatistic.UNKNOWN, derivedRowCount).build());
Review Comment:
new ColumnStatisticBuilder(derivedRowCount).build()
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/stats/JoinEstimation.java:
##########
@@ -177,14 +181,27 @@ private static double
computeSelectivityForBuildSideWhenColStatsUnknown(Statisti
if (cond instanceof EqualTo) {
EqualTo equal = (EqualTo) cond;
if (equal.left() instanceof Slot && equal.right() instanceof
Slot) {
- ColumnStatistic buildColStats =
buildStats.findColumnStatistics(equal.left());
- if (buildColStats == null) {
- buildColStats =
buildStats.findColumnStatistics(equal.right());
+ Slot buildSideSlot = null;
+ if (buildStats.findColumnStatistics(equal.left()) != null)
{
+ buildSideSlot = (Slot) equal.left();
+ } else if (buildStats.findColumnStatistics(equal.right())
!= null) {
+ buildSideSlot = (Slot) equal.right();
}
- if (buildColStats != null) {
- double buildSel = Math.min(buildStats.getRowCount() /
buildColStats.count, 1.0);
- buildSel = Math.max(buildSel,
UNKNOWN_COL_STATS_FILTER_SEL_LOWER_BOUND);
- sel = Math.min(sel, buildSel);
+ // the processing is mainly for olap table since external
table rarely has column level statistics
+ if (buildSideSlot instanceof SlotReference
+ && ((SlotReference)
buildSideSlot).getTable().isPresent()
+ && (((SlotReference)
buildSideSlot).getTable().get() instanceof OlapTable)) {
+ OlapTable olapTable = (OlapTable) ((SlotReference)
buildSideSlot).getTable().get();
+ TableStatsMeta tableStatsMeta =
Env.getCurrentEnv().getAnalysisManager()
+ .findTableStatsStatus(olapTable.getId());
+ if (tableStatsMeta != null) {
+ double tableRowCount =
tableStatsMeta.getRowCount(olapTable.getBaseIndexId());
Review Comment:
1. the base table row count is usually much more than that of rollup.
2. tableStatsMeta.getRowCount(olapTable.getBaseIndexId()) may return -1, if
the table is not analyzed. In fact, BE reported rowCount has higher priority
than that in TableMeta.
3. the assumption: "this slot is a base table slot” is easiy broken by
alias. for example " select .. from (select A as x from T) T1
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/stats/StatsCalculator.java:
##########
@@ -1411,7 +1404,7 @@ private Statistics computeWindow(Window windowOperator) {
private ColumnStatistic unionColumn(ColumnStatistic leftStats, double
leftRowCount, ColumnStatistic rightStats,
double rightRowCount, DataType dataType) {
if (leftStats.isUnKnown() || rightStats.isUnKnown()) {
- return new ColumnStatisticBuilder(leftStats).setCount(leftRowCount
+ rightRowCount).build();
+ return new ColumnStatisticBuilder(leftStats).build();
Review Comment:
return new ColumnStatisticBuilder(leftStats.count +
rightStats.count).build();
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/stats/FilterEstimation.java:
##########
@@ -323,6 +323,8 @@ private Statistics estimateEqualTo(ComparisonPredicate cp,
ColumnStatistic stats
selectivity = DEFAULT_INEQUALITY_COEFFICIENT;
} else {
double ndv = statsForLeft.ndv;
+ double numNulls = statsForLeft.numNulls;
Review Comment:
numNulls = statsForLeft.numNulls * statsForRight.ndv
Usually, this func is used to evaluate join condition: T1.A=T2.B
the context.statistics is in charge of T1 cross join T2, and hence, the
number of tuples, in which A=null or B=null, is A.numNulls * B.numNulls
##########
fe/fe-core/src/main/java/org/apache/doris/statistics/PartitionColumnStatistic.java:
##########
@@ -38,14 +38,14 @@ public class PartitionColumnStatistic {
private static final Logger LOG =
LogManager.getLogger(PartitionColumnStatistic.class);
- public static PartitionColumnStatistic UNKNOWN = new
PartitionColumnStatisticBuilder().setAvgSizeByte(1)
- .setNdv(new
Hll128()).setNumNulls(1).setCount(1).setMaxValue(Double.POSITIVE_INFINITY)
+ public static PartitionColumnStatistic UNKNOWN = new
PartitionColumnStatisticBuilder(1).setAvgSizeByte(1)
+ .setNdv(new
Hll128()).setNumNulls(1).setMaxValue(Double.POSITIVE_INFINITY)
.setMinValue(Double.NEGATIVE_INFINITY)
.setIsUnknown(true).setUpdatedTime("")
.build();
- public static PartitionColumnStatistic ZERO = new
PartitionColumnStatisticBuilder().setAvgSizeByte(0)
- .setNdv(new
Hll128()).setNumNulls(0).setCount(0).setMaxValue(Double.NaN).setMinValue(Double.NaN)
+ public static PartitionColumnStatistic ZERO = new
PartitionColumnStatisticBuilder(0).setAvgSizeByte(0)
Review Comment:
not used any more. Please remove it
##########
fe/fe-core/src/main/java/org/apache/doris/statistics/ColumnStatistic.java:
##########
@@ -197,7 +198,6 @@ public ColumnStatistic updateByLimit(long limit, double
rowCount) {
}
double newNdv = Math.ceil(Math.min(ndv, limit));
return new ColumnStatisticBuilder()
- .setCount(Math.ceil(limit))
Review Comment:
the function "updateByLimit" can be removed.
##########
fe/fe-core/src/main/java/org/apache/doris/statistics/PartitionColumnStatisticBuilder.java:
##########
@@ -50,9 +50,23 @@ public
PartitionColumnStatisticBuilder(PartitionColumnStatistic statistic) {
this.updatedTime = statistic.updatedTime;
}
- public PartitionColumnStatisticBuilder setCount(double count) {
+ // ATTENTION: DON'T USE FOLLOWING TWO DURING STATS DERIVING EXCEPT FOR
INITIALIZATION
+ public PartitionColumnStatisticBuilder(double count) {
this.count = count;
- return this;
+ }
+
+ public PartitionColumnStatisticBuilder(PartitionColumnStatistic
partitionColumnStatistic, double count) {
Review Comment:
partitionColumnStatistic is always unkown, remove it
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