diff --git a/arangod/MMFiles/MMFilesHashIndex.cpp b/arangod/MMFiles/MMFilesHashIndex.cpp
index d3cb2b1068..0ac2b70d20 100644
--- a/arangod/MMFiles/MMFilesHashIndex.cpp
+++ b/arangod/MMFiles/MMFilesHashIndex.cpp
@@ -52,6 +52,7 @@ MMFilesHashIndexLookupBuilder::MMFilesHashIndexLookupBuilder(
     : _builder(trx),
       _usesIn(false),
       _isEmpty(false),
+      _mappingFieldConditionArena(),
       _mappingFieldCondition{_mappingFieldConditionArena},
       _inStorage(trx) {
   TRI_ASSERT(node->type == aql::NODE_TYPE_OPERATOR_NARY_AND);
diff --git a/arangod/MMFiles/MMFilesHashIndex.h b/arangod/MMFiles/MMFilesHashIndex.h
index 85ca3b3231..c9808060ae 100644
--- a/arangod/MMFiles/MMFilesHashIndex.h
+++ b/arangod/MMFiles/MMFilesHashIndex.h
@@ -181,8 +181,8 @@ class MMFilesHashIndexLookupBuilder {
 
   using MappingCondition =
       ::arangodb::containers::SmallVector<arangodb::aql::AstNode const*>;
-  MappingCondition _mappingFieldCondition;
   MappingCondition::allocator_type::arena_type _mappingFieldConditionArena;
+  MappingCondition _mappingFieldCondition;
 
   std::unordered_map<size_t, std::pair<size_t, std::vector<arangodb::velocypack::Slice>>> _inPosition;
   transaction::BuilderLeaser _inStorage;
@@ -272,10 +272,10 @@ class MMFilesHashIndex final : public MMFilesPathBasedIndex {
 
   Index::FilterCosts supportsFilterCondition(std::vector<std::shared_ptr<arangodb::Index>> const& allIndexes,
                                              arangodb::aql::AstNode const* node,
-                                             arangodb::aql::Variable const* reference, 
+                                             arangodb::aql::Variable const* reference,
                                              size_t itemsInIndex) const override;
 
-  std::unique_ptr<IndexIterator> iteratorForCondition(transaction::Methods* trx, 
+  std::unique_ptr<IndexIterator> iteratorForCondition(transaction::Methods* trx,
                                                       arangodb::aql::AstNode const* node,
                                                       arangodb::aql::Variable const* reference,
                                                       IndexIteratorOptions const& opts) override;
diff --git a/arangod/MMFiles/MMFilesPrimaryIndex.cpp b/arangod/MMFiles/MMFilesPrimaryIndex.cpp
index 2fb8841a9a..7c551c2749 100644
--- a/arangod/MMFiles/MMFilesPrimaryIndex.cpp
+++ b/arangod/MMFiles/MMFilesPrimaryIndex.cpp
@@ -21,7 +21,10 @@
 /// @author Dr. Frank Celler
 ////////////////////////////////////////////////////////////////////////////////
 
+#include <algorithm>
+
 #include "Aql/AstNode.h"
+#include "Aql/ExecutionBlock.h"
 #include "Basics/Exceptions.h"
 #include "Basics/StaticStrings.h"
 #include "Basics/hashes.h"
@@ -161,7 +164,7 @@ bool MMFilesAllIndexIterator::next(LocalDocumentIdCallback const& cb, size_t lim
 
 bool MMFilesAllIndexIterator::nextDocument(DocumentCallback const& cb, size_t limit) {
   _documentIds.clear();
-  _documentIds.reserve(limit);
+  _documentIds.reserve((std::min)(limit, aql::ExecutionBlock::DefaultBatchSize()));
 
   bool done = false;
   while (limit > 0) {
@@ -475,8 +478,8 @@ std::unique_ptr<IndexIterator> MMFilesPrimaryIndex::iteratorForCondition(
   if (aap.opType == aql::NODE_TYPE_OPERATOR_BINARY_EQ) {
     // a.b == value
     return createEqIterator(trx, aap.attribute, aap.value);
-  } 
-  
+  }
+
   if (aap.opType == aql::NODE_TYPE_OPERATOR_BINARY_IN &&
       aap.value->isArray()) {
     // a.b IN array