7

xinyiZzz · Oct 23, 2023 · 19bde78 · 19bde78
1 parent 430f87a
commit 19bde78
Showing 1 changed file with 29 additions and 13 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java b/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java
@@ -98,6 +98,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -944,24 +945,37 @@ public void computeSampleTabletIds() {
         }
         OlapTable olapTable = (OlapTable) desc.getTable();
 
-
         long selectedRows = 0;
+        long totalSampleRows = 0;
+        List<Long> selectedPartitionList = new ArrayList<>();
         for (Long partitionId : selectedPartitionIds) {
             final Partition partition = olapTable.getPartition(partitionId);
             final MaterializedIndex selectedTable = partition.getIndex(selectedIndexId);
             selectedRows += selectedTable.getRowCount();
+            selectedPartitionList.add(partitionId);
         }
-        if (tableSample.isPercent() && tableSample.getSampleValue() == 100) {
-            sampleTabletIds.clear();
-            return;
-        } else if (tableSample.getSampleValue() > selectedRows) {
-            sampleTabletIds.clear();
-            return;
+        selectedPartitionList.sort(Comparator.naturalOrder());
+
+        if (tableSample.isPercent()) {
+            if (tableSample.getSampleValue() == 100) {
+                sampleTabletIds.clear();
+                return;
+            }
+            totalSampleRows = (long) Math.max(selectedRows * (tableSample.getSampleValue() / 100.0), 1);
+        } else {
+            if (tableSample.getSampleValue() > selectedRows) {
+                sampleTabletIds.clear();
+                return;
+            }
+            totalSampleRows = tableSample.getSampleValue();
         }
 
         long hitRows = 0; // The number of rows hit by the tablet
-        for (Long partitionId : selectedPartitionIds) {
-            final Partition partition = olapTable.getPartition(partitionId);
+        long partitionSeek = tableSample.getSeek() != -1
+                ? tableSample.getSeek() : (long) (new SecureRandom().nextDouble() * selectedPartitionIds.size());
+        for (int i = 0; i < selectedPartitionList.size(); i++) {
+            int seekPid = (int) ((i + partitionSeek) % selectedPartitionList.size());
+            final Partition partition = olapTable.getPartition(selectedPartitionList.get(seekPid));
             final MaterializedIndex selectedTable = partition.getIndex(selectedIndexId);
             List<Tablet> tablets = selectedTable.getTablets();
             if (tablets.isEmpty()) {
@@ -976,21 +990,23 @@ public void computeSampleTabletIds() {
                         tableSample.getSampleValue() * (selectedTable.getRowCount() / selectedRows), 1);
             }
 
-            long seek = tableSample.getSeek() != -1
+            long tabletSeek = tableSample.getSeek() != -1
                     ? tableSample.getSeek() : (long) (new SecureRandom().nextDouble() * tablets.size());
-            for (int i = 0; i < tablets.size(); i++) {
-                int seekTid = (int) ((i + seek) % tablets.size());
+            for (int j = 0; j < tablets.size(); j++) {
+                int seekTid = (int) ((j + tabletSeek) % tablets.size());
                 if (tablets.get(seekTid).getRowCount(true) == 0) {
                     continue;
                 }
                 sampleTabletIds.add(tablets.get(seekTid).getId());
                 sampleRows -= tablets.get(seekTid).getRowCount(true);
-
                 hitRows += tablets.get(seekTid).getRowCount(true);
                 if (sampleRows <= 0) {
                     break;
                 }
             }
+            if (hitRows > totalSampleRows) {
+                break;
+            }
         }
         LOG.debug("after computeSampleTabletIds, hitRows {}, selectedRows {}", hitRows, selectedRows);
     }