GRIFFIN: some record cursors are able to report their size, which will allow...

GRIFFIN: some record cursors are able to report their size, which will allow us to reduce overhead producing HTTP response and also speed up execution of limits and counts

core/src/main/java/io/questdb/cairo/FullBwdDataFrameCursor.java

@@ -47,4 +47,9 @@ public class FullBwdDataFrameCursor extends AbstractFullDataFrameCursor {
     public void toTop() {
         this.partitionIndex = this.partitionHi - 1;
     }
+
+    @Override
+    public long size() {
+        return reader.size();
+    }
 }

core/src/main/java/io/questdb/cairo/FullFwdDataFrameCursor.java

@@ -43,6 +43,11 @@ public class FullFwdDataFrameCursor extends AbstractFullDataFrameCursor {
         return false;
     }
 
+    @Override
+    public long size() {
+        return reader.size();
+    }
+
     @Override
     public void toTop() {
         this.partitionIndex = 0;

core/src/main/java/io/questdb/cairo/IntervalBwdDataFrameCursor.java

@@ -116,6 +116,11 @@ public class IntervalBwdDataFrameCursor extends AbstractIntervalDataFrameCursor
         return false;
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public void toTop() {
         super.toTop();

core/src/main/java/io/questdb/cairo/IntervalFwdDataFrameCursor.java

@@ -113,6 +113,11 @@ public class IntervalFwdDataFrameCursor extends AbstractIntervalDataFrameCursor
         return false;
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public void toTop() {
         super.toTop();

core/src/main/java/io/questdb/cairo/RecordChain.java

@@ -244,6 +244,11 @@ public class RecordChain implements Closeable, RecordCursor, Mutable, RecordSink
         recordOffset += 8;
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     private class RecordChainRecord implements Record {
         long fixedOffset;
         long baseOffset;

core/src/main/java/io/questdb/cairo/TableReaderRecordCursor.java

@@ -70,6 +70,11 @@ public class TableReaderRecordCursor implements RecordCursor {
         return record;
     }
 
+    @Override
+    public long size() {
+        return reader.size();
+    }
+
     @Override
     public void recordAt(Record record, long rowId) {
         ((TableReaderRecord) record).jumpTo(Rows.toPartitionIndex(rowId), Rows.toLocalRowID(rowId));

core/src/main/java/io/questdb/cairo/map/CompactMapCursor.java

@@ -80,4 +80,9 @@ public class CompactMapCursor implements RecordCursor {
         this.nextOffset = 0;
         this.offsetHi = offsetHi;
     }
+
+    @Override
+    public long size() {
+        return -1;
+    }
 }

core/src/main/java/io/questdb/cairo/map/FastMap.java

@@ -143,7 +143,7 @@ public class FastMap implements Map {
             this.record = new FastMapRecord(null, 0, keyDataOffset, keyBlockOffset, value, keyTypes);
         }
         assert this.keyBlockOffset < kLimit - kStart : "page size is too small for number of columns";
-        this.cursor = new FastMapCursor(record);
+        this.cursor = new FastMapCursor(record, this);
     }
 
     @Override

core/src/main/java/io/questdb/cairo/map/FastMapCursor.java

@@ -29,13 +29,20 @@ import io.questdb.std.Unsafe;
 
 public final class FastMapCursor implements RecordCursor {
     private final FastMapRecord record;
+    private final FastMap map;
     private int remaining;
     private long address;
     private long topAddress;
     private int count;
 
-    FastMapCursor(FastMapRecord record) {
+    FastMapCursor(FastMapRecord record, FastMap map) {
         this.record = record;
+        this.map = map;
+    }
+
+    @Override
+    public long size() {
+        return map.size();
     }
 
     @Override

core/src/main/java/io/questdb/cairo/sql/DataFrameCursor.java

@@ -41,4 +41,6 @@ public interface DataFrameCursor extends ImmutableIterator<DataFrame>, Closeable
     boolean reload();
 
     void toTop();
+
+    long size();
 }

core/src/main/java/io/questdb/cairo/sql/RecordCursor.java

@@ -44,4 +44,6 @@ public interface RecordCursor extends Closeable {
     void recordAt(long rowId);
 
     void toTop();
+
+    long size();
 }

core/src/main/java/io/questdb/cairo/sql/RowCursorFactory.java

@@ -30,4 +30,6 @@ public interface RowCursorFactory {
 
     default void prepareCursor(TableReader tableReader) {
     }
+
+    boolean isEntity();
 }

core/src/main/java/io/questdb/cutlass/http/processors/AbstractQueryContext.java

@@ -52,6 +52,7 @@ public abstract class AbstractQueryContext implements Mutable, Closeable {
     CharSequence query;
     RecordMetadata metadata;
     RecordCursor cursor;
+    long size;
     long count;
     long skip;
     long stop;

core/src/main/java/io/questdb/griffin/engine/AbstractRedBlackTree.java

@@ -31,13 +31,13 @@ import io.questdb.std.Unsafe;
 import java.io.Closeable;
 
 public abstract class AbstractRedBlackTree implements Mutable, Closeable {
+    // parent is at offset 0
     protected static final int O_LEFT = 8;
     // P(8) + L + R + C(1) + REF
-    private static final int BLOCK_SIZE = 8 + 8 + 8 + 1 + 8;
+    private static final int BLOCK_SIZE = 8 + 8 + 8 + 1 + 8; // 33(it would be good to align to power of two, but entry would use way too much memory)
     private static final int O_RIGHT = 16;
     private static final int O_COLOUR = 24;
     private static final int O_REF = 25;
-//    private static final int O_TOP = 33;
 
     private static final byte RED = 1;
     private static final byte BLACK = 0;
@@ -76,18 +76,10 @@ public abstract class AbstractRedBlackTree implements Mutable, Closeable {
         Unsafe.getUnsafe().putLong(blockAddress + O_RIGHT, right);
     }
 
-//    protected static long topOf(long blockAddress) {
-//        return blockAddress == -1 ? -1 : Unsafe.getUnsafe().getLong(blockAddress + O_TOP);
-//    }
-
     protected static long parentOf(long blockAddress) {
         return blockAddress == -1 ? -1 : Unsafe.getUnsafe().getLong(blockAddress);
     }
 
-//    protected static void setTop(long blockAddress, long recRef) {
-//        Unsafe.getUnsafe().putLong(blockAddress + O_TOP, recRef);
-//    }
-
     protected static long parent2Of(long blockAddress) {
         return parentOf(parentOf(blockAddress));
     }
@@ -137,6 +129,10 @@ public abstract class AbstractRedBlackTree implements Mutable, Closeable {
         return p;
     }
 
+    public long size() {
+        return mem.size() / getBlockSize();
+    }
+
     protected void fix(long x) {
         setColor(x, RED);
 

core/src/main/java/io/questdb/griffin/engine/EmptyTableRandomRecordCursor.java

@@ -51,7 +51,13 @@ final public class EmptyTableRandomRecordCursor implements NoRandomAccessRecordC
     public Record newRecord() {
         return record;
     }
+
     @Override
     public void toTop() {
     }
+
+    @Override
+    public long size() {
+        return 0;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/EmptyTableRecordCursor.java

@@ -50,4 +50,9 @@ final public class EmptyTableRecordCursor implements NoRandomAccessRecordCursor
     @Override
     public void toTop() {
     }
+
+    @Override
+    public long size() {
+        return 0;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/LimitRecordCursorFactory.java

@@ -54,6 +54,7 @@ public class LimitRecordCursorFactory extends AbstractRecordCursorFactory {
         private final Function hiFunction;
         private RecordCursor base;
         private long limit;
+        private long size;
 
         public LimitRecordCursor(Function loFunction, Function hiFunction) {
             this.loFunction = loFunction;
@@ -65,6 +66,14 @@ public class LimitRecordCursorFactory extends AbstractRecordCursorFactory {
             base.close();
         }
 
+        @Override
+        public long size() {
+            if (size > -1) {
+                return size;
+            }
+            return -1;
+        }
+
         @Override
         public Record getRecord() {
             return base.getRecord();
@@ -121,9 +130,11 @@ public class LimitRecordCursorFactory extends AbstractRecordCursorFactory {
                 }
                 // set limit to return remaining rows
                 limit = -lo;
+                size = -lo;
             } else if (lo > -1 && hiFunction == null) {
                 // first N rows
                 limit = lo;
+                size = lo;
             } else {
                 // at this stage we have 'hi'
                 long hi = hiFunction.getLong(null);
@@ -141,21 +152,26 @@ public class LimitRecordCursorFactory extends AbstractRecordCursorFactory {
                                 // if we asked for -9,-4 but there are 7 records in cursor
                                 // we would first ignore last 4 and return first 3
                                 limit = count + hi;
+                                size = limit;
                             } else {
                                 skipTo(count + lo);
                                 limit = -lo + hi;
+                                size = limit;
                             }
                         }
                     } else {
                         // this is invalid bottom range, for example -3, -10
                         limit = 0;
+                        size = 0;
                     }
                 } else {
                     if (hi < 0) {
                         limit = countRows() - lo + hi;
+                        size = limit;
                         base.toTop();
                     } else {
                         limit = hi - lo;
+                        size = limit;
                     }
 
                     if (lo > 0 && limit > 0) {
@@ -166,7 +182,10 @@ public class LimitRecordCursorFactory extends AbstractRecordCursorFactory {
         }
 
         private long countRows() {
-            long count = 0;
+            long count = base.size();
+            if (count > -1) {
+                return count;
+            }
             while (base.hasNext()) {
                 count++;
             }

core/src/main/java/io/questdb/griffin/engine/functions/catalogue/ClassCatalogueFunctionFactory.java

@@ -136,6 +136,11 @@ public class ClassCatalogueFunctionFactory implements FunctionFactory {
             return false;
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public void toTop() {
             if (findFileStruct != 0) {

core/src/main/java/io/questdb/griffin/engine/functions/catalogue/NamespaceCatalogueFunctionFactory.java

@@ -84,6 +84,11 @@ public class NamespaceCatalogueFunctionFactory implements FunctionFactory {
         public void toTop() {
             row = 0;
         }
+
+        @Override
+        public long size() {
+            return 1;
+        }
     }
 
     private static class NamespaceCatalogueRecord implements Record {

core/src/main/java/io/questdb/griffin/engine/functions/rnd/LongSequenceFunctionFactory.java

@@ -80,6 +80,11 @@ public class LongSequenceFunctionFactory implements FunctionFactory {
         public void close() {
         }
 
+        @Override
+        public long size() {
+            return recordCount;
+        }
+
         @Override
         public Record getRecord() {
             return record;

core/src/main/java/io/questdb/griffin/engine/groupby/DistinctRecordCursorFactory.java

@@ -151,5 +151,10 @@ public class DistinctRecordCursorFactory implements RecordCursorFactory {
             this.recordSink = recordSink;
             this.record = baseCursor.getRecord();
         }
+
+        @Override
+        public long size() {
+            return -1;
+        }
     }
 }

core/src/main/java/io/questdb/griffin/engine/groupby/GroupByRecordCursorFactory.java

@@ -188,6 +188,11 @@ public class GroupByRecordCursorFactory implements RecordCursorFactory {
             return record;
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public void recordAt(Record record, long atRowId) {
             assert record instanceof VirtualRecord;

core/src/main/java/io/questdb/griffin/engine/groupby/SampleByFillNoneRecordCursor.java

@@ -73,6 +73,11 @@ class SampleByFillNoneRecordCursor implements DelegatingRecordCursor, NoRandomAc
         this.mapCursor = map.getCursor();
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public void close() {
         base.close();

core/src/main/java/io/questdb/griffin/engine/groupby/SampleByFillPrevRecordCursor.java

@@ -185,6 +185,11 @@ class SampleByFillPrevRecordCursor implements DelegatingRecordCursor, NoRandomAc
         }
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public void of(RecordCursor base) {
         // factory guarantees that base cursor is not empty

core/src/main/java/io/questdb/griffin/engine/groupby/SampleByFillValueRecordCursor.java

@@ -168,6 +168,11 @@ class SampleByFillValueRecordCursor implements DelegatingRecordCursor, NoRandomA
         }
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public void toTop() {
         this.base.toTop();

core/src/main/java/io/questdb/griffin/engine/groupby/SampleByInterpolateRecordCursorFactory.java

@@ -491,6 +491,11 @@ public class SampleByInterpolateRecordCursorFactory implements RecordCursorFacto
             return mapCursor.hasNext();
         }
 
+        @Override
+        public long size() {
+            return mapCursor.size();
+        }
+
         @Override
         public Record newRecord() {
             VirtualRecord record = new VirtualRecord(functionRecord.getFunctions());

core/src/main/java/io/questdb/griffin/engine/join/AsOfJoinLightRecordCursorFactory.java

@@ -43,7 +43,7 @@ public class AsOfJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
     private final RecordCursorFactory slaveFactory;
     private final RecordSink masterKeySink;
     private final RecordSink slaveKeySink;
-    private final HashJoinRecordCursor cursor;
+    private final AsOfLightJoinRecordCursor cursor;
 
     public AsOfJoinLightRecordCursorFactory(
             CairoConfiguration configuration,
@@ -63,7 +63,7 @@ public class AsOfJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
         joinKeyMap = MapFactory.createMap(configuration, joinColumnTypes, valueTypes);
         this.masterKeySink = masterKeySink;
         this.slaveKeySink = slaveKeySink;
-        this.cursor = new HashJoinRecordCursor(
+        this.cursor = new AsOfLightJoinRecordCursor(
                 columnSplit,
                 joinKeyMap,
                 NullRecordFactory.getInstance(slaveFactory.getMetadata()),
@@ -94,7 +94,7 @@ public class AsOfJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
         return false;
     }
 
-    private class HashJoinRecordCursor implements NoRandomAccessRecordCursor {
+    private class AsOfLightJoinRecordCursor implements NoRandomAccessRecordCursor {
         private final OuterJoinRecord record;
         private final Map joinKeyMap;
         private final int columnSplit;
@@ -107,7 +107,7 @@ public class AsOfJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
         private long slaveTimestamp = Long.MIN_VALUE;
         private long lastSlaveRowID = Long.MIN_VALUE;
 
-        public HashJoinRecordCursor(int columnSplit, Map joinKeyMap, Record nullRecord, int masterTimestampIndex, int slaveTimestampIndex) {
+        public AsOfLightJoinRecordCursor(int columnSplit, Map joinKeyMap, Record nullRecord, int masterTimestampIndex, int slaveTimestampIndex) {
             this.record = new OuterJoinRecord(columnSplit, nullRecord);
             this.joinKeyMap = joinKeyMap;
             this.columnSplit = columnSplit;
@@ -134,6 +134,11 @@ public class AsOfJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public boolean hasNext() {
 

core/src/main/java/io/questdb/griffin/engine/join/AsOfJoinRecordCursorFactory.java

@@ -145,6 +145,11 @@ public class AsOfJoinRecordCursorFactory extends AbstractRecordCursorFactory {
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public boolean hasNext() {
 

core/src/main/java/io/questdb/griffin/engine/join/CrossJoinRecordCursorFactory.java

@@ -101,6 +101,16 @@ public class CrossJoinRecordCursorFactory extends AbstractRecordCursorFactory {
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            long sizeA = masterCursor.size();
+            long sizeB = slaveCursor.size();
+            if (sizeA == -1 || sizeB == -1) {
+                return -1;
+            }
+            return sizeA * sizeB;
+        }
+
         @Override
         public boolean hasNext() {
 

core/src/main/java/io/questdb/griffin/engine/join/HashJoinLightRecordCursorFactory.java

@@ -145,6 +145,11 @@ public class HashJoinLightRecordCursorFactory extends AbstractRecordCursorFactor
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public boolean hasNext() {
             if (slaveChainCursor != null && slaveChainCursor.hasNext()) {

core/src/main/java/io/questdb/griffin/engine/join/HashJoinRecordCursorFactory.java

@@ -132,6 +132,11 @@ public class HashJoinRecordCursorFactory extends AbstractRecordCursorFactory {
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public boolean hasNext() {
             if (useSlaveCursor && slaveChain.hasNext()) {

core/src/main/java/io/questdb/griffin/engine/join/HashOuterJoinLightRecordCursorFactory.java

@@ -40,7 +40,7 @@ public class HashOuterJoinLightRecordCursorFactory extends AbstractRecordCursorF
     private final RecordCursorFactory slaveFactory;
     private final RecordSink masterKeySink;
     private final RecordSink slaveKeySink;
-    private final HashJoinRecordCursor cursor;
+    private final HashOuterJoinLightRecordCursor cursor;
 
     public HashOuterJoinLightRecordCursorFactory(
             CairoConfiguration configuration,
@@ -61,7 +61,7 @@ public class HashOuterJoinLightRecordCursorFactory extends AbstractRecordCursorF
         slaveChain = new LongChain(configuration.getSqlHashJoinLightValuePageSize());
         this.masterKeySink = masterKeySink;
         this.slaveKeySink = slaveKeySink;
-        this.cursor = new HashJoinRecordCursor(
+        this.cursor = new HashOuterJoinLightRecordCursor(
                 columnSplit,
                 joinKeyMap,
                 slaveChain,
@@ -114,7 +114,7 @@ public class HashOuterJoinLightRecordCursorFactory extends AbstractRecordCursorF
         }
     }
 
-    private class HashJoinRecordCursor implements NoRandomAccessRecordCursor {
+    private class HashOuterJoinLightRecordCursor implements NoRandomAccessRecordCursor {
         private final OuterJoinRecord record;
         private final LongChain slaveChain;
         private final Map joinKeyMap;
@@ -124,7 +124,7 @@ public class HashOuterJoinLightRecordCursorFactory extends AbstractRecordCursorF
         private Record masterRecord;
         private LongChain.TreeCursor slaveChainCursor;
 
-        public HashJoinRecordCursor(
+        public HashOuterJoinLightRecordCursor(
                 int columnSplit,
                 Map joinKeyMap,
                 LongChain slaveChain,
@@ -142,6 +142,11 @@ public class HashOuterJoinLightRecordCursorFactory extends AbstractRecordCursorF
             slaveCursor = Misc.free(slaveCursor);
         }
 
+        @Override
+        public long size() {
+            return -1L;
+        }
+
         @Override
         public Record getRecord() {
             return record;

core/src/main/java/io/questdb/griffin/engine/join/HashOuterJoinRecordCursorFactory.java

@@ -40,7 +40,7 @@ public class HashOuterJoinRecordCursorFactory extends AbstractRecordCursorFactor
     private final RecordCursorFactory slaveFactory;
     private final RecordSink masterSink;
     private final RecordSink slaveKeySink;
-    private final HashJoinRecordCursor cursor;
+    private final HashOuterJoinRecordCursor cursor;
 
     public HashOuterJoinRecordCursorFactory(
             CairoConfiguration configuration,
@@ -62,7 +62,7 @@ public class HashOuterJoinRecordCursorFactory extends AbstractRecordCursorFactor
         slaveChain = new RecordChain(slaveFactory.getMetadata(), slaveChainSink, configuration.getSqlHashJoinValuePageSize());
         this.masterSink = masterSink;
         this.slaveKeySink = slaveKeySink;
-        this.cursor = new HashJoinRecordCursor(
+        this.cursor = new HashOuterJoinRecordCursor(
                 columnSplit,
                 joinKeyMap,
                 slaveChain,
@@ -118,7 +118,7 @@ public class HashOuterJoinRecordCursorFactory extends AbstractRecordCursorFactor
         buildMap(slaveCursor, slaveCursor.getRecord(), joinKeyMap, slaveKeySink, slaveChain);
     }
 
-    private class HashJoinRecordCursor implements NoRandomAccessRecordCursor {
+    private class HashOuterJoinRecordCursor implements NoRandomAccessRecordCursor {
         private final OuterJoinRecord record;
         private final RecordChain slaveChain;
         private final Map joinKeyMap;
@@ -128,7 +128,7 @@ public class HashOuterJoinRecordCursorFactory extends AbstractRecordCursorFactor
         private Record masterRecord;
         private boolean useSlaveCursor;
 
-        public HashJoinRecordCursor(int columnSplit, Map joinKeyMap, RecordChain slaveChain, Record nullRecord) {
+        public HashOuterJoinRecordCursor(int columnSplit, Map joinKeyMap, RecordChain slaveChain, Record nullRecord) {
             this.record = new OuterJoinRecord(columnSplit, nullRecord);
             this.joinKeyMap = joinKeyMap;
             this.slaveChain = slaveChain;
@@ -141,6 +141,11 @@ public class HashOuterJoinRecordCursorFactory extends AbstractRecordCursorFactor
             slaveCursor = Misc.free(slaveCursor);
         }
 
+        @Override
+        public long size() {
+            return -1;
+        }
+
         @Override
         public Record getRecord() {
             return record;

core/src/main/java/io/questdb/griffin/engine/join/SpliceJoinLightRecordCursorFactory.java

@@ -61,7 +61,7 @@ public class SpliceJoinLightRecordCursorFactory extends AbstractRecordCursorFact
     private final Map joinKeyMap;
     private final RecordSink masterKeySink;
     private final RecordSink slaveKeySink;
-    private final FullAslOfJoinCursor cursor;
+    private final SpliceJoinLightRecordCursor cursor;
 
     public SpliceJoinLightRecordCursorFactory(
             CairoConfiguration cairoConfiguration,
@@ -84,7 +84,7 @@ public class SpliceJoinLightRecordCursorFactory extends AbstractRecordCursorFact
         );
         this.masterKeySink = masterSink;
         this.slaveKeySink = slaveSink;
-        this.cursor = new FullAslOfJoinCursor(
+        this.cursor = new SpliceJoinLightRecordCursor(
                 joinKeyMap,
                 columnSplit,
                 masterFactory.getMetadata().getTimestampIndex(),
@@ -272,7 +272,7 @@ public class SpliceJoinLightRecordCursorFactory extends AbstractRecordCursorFact
         }
     }
 
-    private class FullAslOfJoinCursor implements NoRandomAccessRecordCursor {
+    private class SpliceJoinLightRecordCursor implements NoRandomAccessRecordCursor {
         private final FullJoinRecord record;
         private final Map joinKeyMap;
         private final int columnSplit;
@@ -296,7 +296,7 @@ public class SpliceJoinLightRecordCursorFactory extends AbstractRecordCursorFact
         private boolean hasSlave = true;
         private boolean dualRecord = false;
 
-        public FullAslOfJoinCursor(
+        public SpliceJoinLightRecordCursor(
                 Map joinKeyMap,
                 int columnSplit,
                 int masterTimestampIndex,
@@ -332,6 +332,11 @@ public class SpliceJoinLightRecordCursorFactory extends AbstractRecordCursorFact
             return slaveCursor.getSymbolTable(columnIndex - columnSplit);
         }
 
+        @Override
+        public long size() {
+            return -1L;
+        }
+
         @Override
         public boolean hasNext() {
             if (dualRecord) {

core/src/main/java/io/questdb/griffin/engine/orderby/RecordTreeChain.java

@@ -330,6 +330,11 @@ public class RecordTreeChain implements Closeable, Mutable {
             return recordChain.hasNext();
         }
 
+        @Override
+        public long size() {
+            return base.size();
+        }
+
         @Override
         public Record newRecord() {
             return recordChain.newRecord();

core/src/main/java/io/questdb/griffin/engine/orderby/SortedLightRecordCursor.java

@@ -49,6 +49,11 @@ class SortedLightRecordCursor implements DelegatingRecordCursor {
         base.close();
     }
 
+    @Override
+    public long size() {
+        return base.size();
+    }
+
     @Override
     public Record getRecord() {
         return baseRecord;

core/src/main/java/io/questdb/griffin/engine/orderby/SortedRecordCursor.java

@@ -77,6 +77,11 @@ class SortedRecordCursor implements DelegatingRecordCursor {
         chainCursor.toTop();
     }
 
+    @Override
+    public long size() {
+        return chainCursor.size();
+    }
+
     @Override
     public void of(RecordCursor base) {
         this.chainCursor = chain.getCursor(base);

core/src/main/java/io/questdb/griffin/engine/table/AbstractTreeSetRecordCursor.java

@@ -42,6 +42,11 @@ abstract class AbstractTreeSetRecordCursor extends AbstractDataFrameRecordCursor
         treeCursor = null;
     }
 
+    @Override
+    public long size() {
+        return treeSet.size();
+    }
+
     abstract protected void buildTreeMap(SqlExecutionContext executionContext);
 
     @Override

core/src/main/java/io/questdb/griffin/engine/table/DataFrameRecordCursor.java

@@ -30,11 +30,13 @@ import org.jetbrains.annotations.Nullable;
 class DataFrameRecordCursor extends AbstractDataFrameRecordCursor {
     private final RowCursorFactory rowCursorFactory;
     private final Function filter;
+    private final boolean entityCursor;
     private RowCursor rowCursor;
 
-    public DataFrameRecordCursor(RowCursorFactory rowCursorFactory, @Nullable Function filter) {
+    public DataFrameRecordCursor(RowCursorFactory rowCursorFactory, @Nullable Function filter, boolean entityCursor) {
         this.rowCursorFactory = rowCursorFactory;
         this.filter = filter;
+        this.entityCursor = entityCursor;
     }
 
     @Override
@@ -73,6 +75,11 @@ class DataFrameRecordCursor extends AbstractDataFrameRecordCursor {
         }
     }
 
+    @Override
+    public long size() {
+        return entityCursor ? dataFrameCursor.size() : -1;
+    }
+
     private boolean nextFrame() {
         while (dataFrameCursor.hasNext()) {
             DataFrame dataFrame = dataFrameCursor.next();

core/src/main/java/io/questdb/griffin/engine/table/DataFrameRecordCursorFactory.java

@@ -37,7 +37,7 @@ public class DataFrameRecordCursorFactory extends AbstractDataFrameRecordCursorF
             RowCursorFactory rowCursorFactory,
             @Nullable Function filter) {
         super(metadata, dataFrameCursorFactory);
-        this.cursor = new DataFrameRecordCursor(rowCursorFactory, filter);
+        this.cursor = new DataFrameRecordCursor(rowCursorFactory, filter, rowCursorFactory.isEntity());
         this.filter = filter;
     }
 

core/src/main/java/io/questdb/griffin/engine/table/DataFrameRowCursorFactory.java

@@ -36,4 +36,8 @@ public class DataFrameRowCursorFactory implements RowCursorFactory {
         return cursor;
     }
 
+    @Override
+    public boolean isEntity() {
+        return true;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/DeferredSymbolIndexFilteredRowCursorFactory.java

@@ -55,4 +55,9 @@ public class DeferredSymbolIndexFilteredRowCursorFactory implements RowCursorFac
             this.cursor.setTableReader(tableReader);
         }
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/DeferredSymbolIndexRowCursorFactory.java

@@ -63,4 +63,9 @@ public class DeferredSymbolIndexRowCursorFactory implements RowCursorFactory {
             this.symbolKey = TableUtils.toIndexKey(symbolKey);
         }
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/FilterOnSubQueryRecordCursorFactory.java

@@ -60,7 +60,7 @@ public class FilterOnSubQueryRecordCursorFactory extends AbstractDataFrameRecord
         this.filter = filter;
         this.factories = factoriesA;
         cursorFactories = new ObjList<>();
-        this.cursor = new DataFrameRecordCursor(new HeapRowCursorFactory(cursorFactories), filter);
+        this.cursor = new DataFrameRecordCursor(new HeapRowCursorFactory(cursorFactories), filter, false);
         if (firstColumnType == ColumnType.SYMBOL) {
             typeCaster = SymbolTypeCaster.INSTANCE;
         } else {

core/src/main/java/io/questdb/griffin/engine/table/FilterOnValuesRecordCursorFactory.java

@@ -68,7 +68,7 @@ public class FilterOnValuesRecordCursorFactory extends AbstractDataFrameRecordCu
                 deferredSymbols.add(Chars.toString(symbol));
             }
         }
-        this.cursor = new DataFrameRecordCursor(new HeapRowCursorFactory(cursorFactories), filter);
+        this.cursor = new DataFrameRecordCursor(new HeapRowCursorFactory(cursorFactories), filter, false);
     }
 
     @Override

core/src/main/java/io/questdb/griffin/engine/table/FilteredRecordCursor.java

@@ -63,6 +63,11 @@ class FilteredRecordCursor implements RecordCursor {
         return false;
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     public Record newRecord() {
         return base.newRecord();

core/src/main/java/io/questdb/griffin/engine/table/HeapRowCursorFactory.java

@@ -40,6 +40,11 @@ public class HeapRowCursorFactory implements RowCursorFactory {
         this.cursor = new HeapRowCursor();
     }
 
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
+
     @Override
     public RowCursor getCursor(DataFrame dataFrame) {
         for (int i = 0, n = cursorFactories.size(); i < n; i++) {

core/src/main/java/io/questdb/griffin/engine/table/LatestByValueDeferredIndexedRowCursorFactory.java

@@ -70,4 +70,9 @@ public class LatestByValueDeferredIndexedRowCursorFactory implements RowCursorFa
             }
         }
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/LatestByValueFilteredRecordCursor.java

@@ -63,6 +63,11 @@ class LatestByValueFilteredRecordCursor extends AbstractDataFrameRecordCursor {
         return false;
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     void of(DataFrameCursor dataFrameCursor, SqlExecutionContext executionContext) {
         this.dataFrameCursor = dataFrameCursor;

core/src/main/java/io/questdb/griffin/engine/table/LatestByValueIndexedFilteredRecordCursor.java

@@ -85,6 +85,11 @@ class LatestByValueIndexedFilteredRecordCursor extends AbstractDataFrameRecordCu
         }
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     void of(DataFrameCursor dataFrameCursor, SqlExecutionContext executionContext) {
         this.dataFrameCursor = dataFrameCursor;

core/src/main/java/io/questdb/griffin/engine/table/LatestByValueIndexedRowCursorFactory.java

@@ -55,4 +55,9 @@ public class LatestByValueIndexedRowCursorFactory implements RowCursorFactory {
         }
         return EmptyRowCursor.INSTANCE;
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/LatestByValueRecordCursor.java

@@ -73,6 +73,11 @@ class LatestByValueRecordCursor extends AbstractDataFrameRecordCursor {
         }
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     @Override
     void of(DataFrameCursor dataFrameCursor, SqlExecutionContext executionContext) {
         this.dataFrameCursor = dataFrameCursor;

core/src/main/java/io/questdb/griffin/engine/table/SelectedRecordCursor.java

@@ -53,6 +53,11 @@ class SelectedRecordCursor implements RecordCursor {
         return baseCursor.getSymbolTable(columnCrossIndex.getQuick(columnIndex));
     }
 
+    @Override
+    public long size() {
+        return baseCursor.size();
+    }
+
     @Override
     public boolean hasNext() {
         return baseCursor.hasNext();

core/src/main/java/io/questdb/griffin/engine/table/SymbolIndexFilteredRowCursorFactory.java

@@ -45,4 +45,9 @@ public class SymbolIndexFilteredRowCursorFactory implements RowCursorFactory {
     public void prepareCursor(TableReader tableReader) {
         this.cursor.setTableReader(tableReader);
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/SymbolIndexRowCursorFactory.java

@@ -46,4 +46,9 @@ public class SymbolIndexRowCursorFactory implements RowCursorFactory {
                 .getBitmapIndexReader(columnIndex, BitmapIndexReader.DIR_FORWARD)
                 .getCursor(cachedIndexReaderCursor, symbolKey, dataFrame.getRowLo(), dataFrame.getRowHi() - 1);
     }
+
+    @Override
+    public boolean isEntity() {
+        return false;
+    }
 }

core/src/main/java/io/questdb/griffin/engine/table/VirtualRecordCursor.java

@@ -59,6 +59,11 @@ class VirtualRecordCursor implements RecordCursor {
         return baseCursor.hasNext();
     }
 
+    @Override
+    public long size() {
+        return baseCursor.size();
+    }
+
     @Override
     public Record newRecord() {
         final VirtualRecord record = new VirtualRecord(this.record.getFunctions());

core/src/main/java/io/questdb/griffin/engine/union/UnionAllRecordCursor.java

@@ -68,6 +68,16 @@ class UnionAllRecordCursor implements NoRandomAccessRecordCursor {
         return slaveCursor.hasNext();
     }
 
+    @Override
+    public long size() {
+        final long masterSize = masterCursor.size();
+        final long slaveSize = slaveCursor.size();
+        if (masterSize == -1 || slaveSize == -1) {
+            return -1;
+        }
+        return masterSize + slaveSize;
+    }
+
     @Override
     public SymbolTable getSymbolTable(int columnIndex) {
         return symbolCursor.getSymbolTable(columnIndex);

core/src/main/java/io/questdb/griffin/engine/union/UnionRecordCursor.java

@@ -125,6 +125,11 @@ class UnionRecordCursor implements NoRandomAccessRecordCursor {
         slaveCursor.toTop();
     }
 
+    @Override
+    public long size() {
+        return -1;
+    }
+
     interface NextMethod {
         boolean next();
     }

core/src/test/java/io/questdb/griffin/AbstractGriffinTest.java

@@ -128,9 +128,15 @@ public class AbstractGriffinTest extends AbstractCairoTest {
             Assert.assertNotNull(record);
             sink.clear();
             printer.printHeader(metadata);
+            long count = 0;
+            long cursorSize = cursor.size();
             while (cursor.hasNext()) {
                 printer.print(record, metadata);
+                count++;
             }
+
+            Assert.assertTrue(cursorSize == -1 || count == cursorSize);
+
             TestUtils.assertEquals(expected, sink);
 
             if (supportsRandomAccess) {

core/src/test/java/io/questdb/griffin/engine/functions/rnd/RandomRecordCursor.java

@@ -39,6 +39,11 @@ class RandomRecordCursor implements NoRandomAccessRecordCursor {
         recordIndex = 0;
     }
 
+    @Override
+    public long size() {
+        return recordCount;
+    }
+
     @Override
     public void close() {
     }