fix bugs

Signed-off-by: shuming.li <[email protected]>
StarRocks · Oct 14, 2024 · fca6261 · fca6261
1 parent a71acc1
commit fca6261
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Showing 4 changed files with 28 additions and 34 deletions.
diff --git a/...rocks/sql/optimizer/rule/transformation/materialization/AggregatedTimeSeriesRewriter.java b/...rocks/sql/optimizer/rule/transformation/materialization/AggregatedTimeSeriesRewriter.java
@@ -86,6 +86,21 @@
 import static com.starrocks.sql.optimizer.rule.transformation.materialization.common.AggregatePushDownUtils.getPushDownRollupFinalAggregateOpt;
 import static com.starrocks.sql.optimizer.rule.transformation.materialization.common.AggregatePushDownUtils.getRollupPartialAggregate;
 
+/**
+ * In time-series business scenarios, metrics are aggregated based on the time dimension, with historical
+ * data continuously being archived (rolled up, compressed), while new data flows in real-time.
+ * By using Materialized Views (MVs) to speed up, different time granularity of MVs can be constructed,
+ * the most common being day, month, and year. However, when querying the base table (original table),
+ * it is hoped that the archived year, month, and day data can be used to speed up time slicing.
+ *
+ * <p> Implementation </p>
+ * Place the logic of splitting time predicates in time-series scenarios + the logic of aggregation push-down into a Rule. When
+ * it can be rewritten, rewrite the output; otherwise, do not change the original Query.
+ * Reuse the aggregation push-down + rewriting capabilities, and implement aggregation push-down + rolling up based on the
+ * aggregation status defined by the materialized view (later, general aggregation status can be used).
+ * Reuse the capability of nested MV rewriting, recursively call this Rule,
+ * and rewrite the scope of granularity as much as possible in one go.
+ */
 public class AggregatedTimeSeriesRewriter extends MaterializedViewRewriter {
     private static final Logger LOG = LogManager.getLogger(AggregatedTimeSeriesRewriter.class);
 

diff --git a/...com/starrocks/sql/optimizer/rule/transformation/materialization/ColumnRangePredicate.java b/...com/starrocks/sql/optimizer/rule/transformation/materialization/ColumnRangePredicate.java
@@ -65,6 +65,15 @@ public class ColumnRangePredicate extends RangePredicate {
 
     private TreeRangeSet<ConstantOperator> canonicalColumnRanges;
 
+    public static ColumnRangePredicate FALSE = new ColumnRangePredicate(TreeRangeSet.create());
+
+    public ColumnRangePredicate(TreeRangeSet<ConstantOperator> columnRanges) {
+        this.columnRanges = columnRanges;
+        this.expression = null;
+        this.columnRef = null;
+        this.canonicalColumnRanges = columnRanges;
+    }
+
     public ColumnRangePredicate(ScalarOperator expression, TreeRangeSet<ConstantOperator> columnRanges) {
         this.expression = expression;
         List<ColumnRefOperator> columns = Utils.collect(expression, ColumnRefOperator.class);
@@ -99,15 +108,15 @@ public static ColumnRangePredicate andRange(
                 for (Range<ConstantOperator> otherRange : otherRangePredicate.columnRanges.asRanges()) {
                     // once there is a range that is not connected with the range, the result is null
                     if (!range.isConnected(otherRange)) {
-                        return null;
+                        return FALSE;
                     }
                     Range<ConstantOperator> intersection = range.intersection(otherRange);
                     if (!intersection.isEmpty()) {
                         ranges.add(intersection);
                     }
                 }
             } else {
-                return null;
+                return FALSE;
             }
         }
         return new ColumnRangePredicate(rangePredicate.getExpression(), TreeRangeSet.create(ranges));

diff --git a/.../com/starrocks/sql/optimizer/rule/transformation/materialization/ConstRangePredicate.java b/.../com/starrocks/sql/optimizer/rule/transformation/materialization/ConstRangePredicate.java
diff --git a/...a/com/starrocks/sql/optimizer/rule/transformation/materialization/PredicateExtractor.java b/...a/com/starrocks/sql/optimizer/rule/transformation/materialization/PredicateExtractor.java
@@ -237,8 +237,8 @@ private void mergeColumnRange(
                 if (columnRangePredicateMap.containsKey(columnRangePredicate.getExpression())) {
                     ColumnRangePredicate newRangePredicate = columnRangePredicateMap.get(columnRangePredicate.getExpression());
                     newRangePredicate = mergeOp.apply(newRangePredicate, columnRangePredicate);
-                    if (newRangePredicate == null) {
-                        rangePredicates.add(new ConstRangePredicate(false));
+                    if (newRangePredicate.equals(ColumnRangePredicate.FALSE)) {
+                        rangePredicates.add(newRangePredicate);
                         return;
                     }
                     if (newRangePredicate.isUnbounded()) {