Lazy Virtual Tables

Also Improve:
 - Searchable system_accord_debug.txn
 - Integrate txn_blocked_by deadline and depth filter with execution logic, to ensure we terminate promptly and get a best effort reply

patch by Benedict; reviewed by Aleksey Yeschenko for CASSANDRA-20899

Author: belliottsmith

src/java/org/apache/cassandra/cql3/restrictions/StatementRestrictions.java

@@ -156,13 +156,13 @@ public static StatementRestrictions empty(StatementType type, TableMetadata tabl
         return new StatementRestrictions(type, table, IndexHints.NONE, false);
     }
 
-    private StatementRestrictions(StatementType type, TableMetadata table, IndexHints indexHints, boolean allowFiltering)
+    private StatementRestrictions(StatementType type, TableMetadata table, IndexHints indexHints, boolean allowFilteringOfPrimaryKeys)
     {
         this.type = type;
         this.table = table;
         this.indexHints = indexHints;
         this.partitionKeyRestrictions = new PartitionKeyRestrictions(table.partitionKeyAsClusteringComparator());
-        this.clusteringColumnsRestrictions = new ClusteringColumnRestrictions(table, allowFiltering);
+        this.clusteringColumnsRestrictions = new ClusteringColumnRestrictions(table, allowFilteringOfPrimaryKeys);
         this.nonPrimaryKeyRestrictions = RestrictionSet.empty();
         this.notNullColumns = new HashSet<>();
     }
@@ -370,7 +370,7 @@ else if (operator.requiresIndexing())
             }
             else
             {
-                if (!allowFiltering && requiresAllowFilteringIfNotSpecified(table))
+                if (!allowFiltering && requiresAllowFilteringIfNotSpecified(table, false))
                     throw invalidRequest(allowFilteringMessage(state));
             }
 
@@ -381,14 +381,14 @@ else if (operator.requiresIndexing())
             validateSecondaryIndexSelections();
     }
 
-    public static boolean requiresAllowFilteringIfNotSpecified(TableMetadata metadata)
+    public static boolean requiresAllowFilteringIfNotSpecified(TableMetadata metadata, boolean isPrimaryKey)
     {
         if (!metadata.isVirtual())
             return true;
 
         VirtualTable tableNullable = VirtualKeyspaceRegistry.instance.getTableNullable(metadata.id);
         assert tableNullable != null;
-        return !tableNullable.allowFilteringImplicitly();
+        return isPrimaryKey ? !tableNullable.allowFilteringPrimaryKeysImplicitly() : !tableNullable.allowFilteringImplicitly();
     }
 
     private void addRestriction(Restriction restriction, IndexRegistry indexRegistry, IndexHints indexHints)
@@ -593,7 +593,7 @@ private void processPartitionKeyRestrictions(ClientState state, boolean hasQueri
             // components must have a EQ. Only the last partition key component can be in IN relation.
             if (partitionKeyRestrictions.needFiltering())
             {
-                if (!allowFiltering && !forView && !hasQueriableIndex && requiresAllowFilteringIfNotSpecified(table))
+                if (!allowFiltering && !forView && !hasQueriableIndex && requiresAllowFilteringIfNotSpecified(table, true))
                     throw new InvalidRequestException(allowFilteringMessage(state));
 
                 isKeyRange = true;

src/java/org/apache/cassandra/cql3/statements/SelectStatement.java

@@ -1474,7 +1474,7 @@ private StatementRestrictions prepareRestrictions(ClientState state,
                                              boundNames,
                                              orderings,
                                              selectsOnlyStaticColumns,
-                                             parameters.allowFiltering || !requiresAllowFilteringIfNotSpecified(metadata),
+                                             parameters.allowFiltering || !requiresAllowFilteringIfNotSpecified(metadata, true),
                                              forView);
         }
 
@@ -1700,7 +1700,7 @@ private void checkNeedsFiltering(TableMetadata table, StatementRestrictions rest
             {
                 // We will potentially filter data if the row filter is not the identity and there isn't any index group
                 // supporting all the expressions in the filter.
-                if (requiresAllowFilteringIfNotSpecified(table))
+                if (requiresAllowFilteringIfNotSpecified(table, true))
                     checkFalse(restrictions.needFiltering(table), StatementRestrictions.REQUIRES_ALLOW_FILTERING_MESSAGE);
             }
         }

src/java/org/apache/cassandra/db/PartitionRangeReadCommand.java

@@ -647,7 +647,7 @@ public PartitionIterator execute(ConsistencyLevel consistency, ClientState state
         public UnfilteredPartitionIterator executeLocally(ReadExecutionController executionController)
         {
             VirtualTable view = VirtualKeyspaceRegistry.instance.getTableNullable(metadata().id);
-            UnfilteredPartitionIterator resultIterator = view.select(dataRange, columnFilter(), rowFilter());
+            UnfilteredPartitionIterator resultIterator = view.select(dataRange, columnFilter(), rowFilter(), limits());
             return limits().filter(rowFilter().filter(resultIterator, nowInSec()), nowInSec(), selectsFullPartition());
         }
 

src/java/org/apache/cassandra/db/SinglePartitionReadCommand.java

@@ -1516,7 +1516,7 @@ public PartitionIterator execute(ConsistencyLevel consistency, ClientState state
         public UnfilteredPartitionIterator executeLocally(ReadExecutionController executionController)
         {
             VirtualTable view = VirtualKeyspaceRegistry.instance.getTableNullable(metadata().id);
-            UnfilteredPartitionIterator resultIterator = view.select(partitionKey, clusteringIndexFilter, columnFilter(), rowFilter());
+            UnfilteredPartitionIterator resultIterator = view.select(partitionKey, clusteringIndexFilter, columnFilter(), rowFilter(), limits());
             return limits().filter(rowFilter().filter(resultIterator, nowInSec()), nowInSec(), selectsFullPartition());
         }
 

src/java/org/apache/cassandra/db/marshal/TxnIdUtf8Type.java

@@ -36,7 +36,7 @@ public <V> void validate(V value, ValueAccessor<V> accessor) throws MarshalExcep
         {
             super.validate(value, accessor);
             String str = deserialize(value, accessor);
-            if (null == TxnId.tryParse(str))
+            if (!str.isEmpty() && null == TxnId.tryParse(str))
                 throw new MarshalException("Invalid TxnId: " + str);
         }
     };
@@ -59,6 +59,12 @@ public <VL, VR> int compareCustom(VL left, ValueAccessor<VL> accessorL, VR right
     {
         String leftStr = UTF8Serializer.instance.deserialize(left, accessorL);
         String rightStr = UTF8Serializer.instance.deserialize(right, accessorR);
+        if (leftStr.isEmpty() || rightStr.isEmpty())
+        {
+            if (leftStr.isEmpty() && rightStr.isEmpty())
+                return 0;
+            return leftStr.isEmpty() ? -1 : 1;
+        }
         TxnId leftId = TxnId.parse(leftStr);
         TxnId rightId = TxnId.parse(rightStr);
         return leftId.compareTo(rightId);