diff --git a/source/net/yacy/kelondro/blob/HeapReader.java b/source/net/yacy/kelondro/blob/HeapReader.java
index 22f8449a0..7dbe44dc8 100644
--- a/source/net/yacy/kelondro/blob/HeapReader.java
+++ b/source/net/yacy/kelondro/blob/HeapReader.java
@@ -51,7 +51,7 @@ import net.yacy.kelondro.util.MemoryControl;
 
 public class HeapReader {
 
-    public final static long keepFreeMem = 20 * 1024 * 1024;
+    //public final static long keepFreeMem = 20 * 1024 * 1024;
     
     // input values
     protected int                keylength;  // the length of the primary key
@@ -414,12 +414,18 @@ public class HeapReader {
                 index.remove(key);
                 return null;
             }
-            if (MemoryControl.available() < len * 2 + keepFreeMem) {
-                if (!MemoryControl.request(len * 2 + keepFreeMem, true)) throw new RowSpaceExceededException(len * 2 + keepFreeMem, "HeapReader.get()"); // not enough memory available for this blob
+            long memr = len + index.row().primaryKeyLength + 64;
+            if (MemoryControl.available() < memr) {
+                if (!MemoryControl.request(memr, true)) throw new RowSpaceExceededException(memr, "HeapReader.get()/check"); // not enough memory available for this blob
             }
             
             // read the key
-            final byte[] keyf = new byte[index.row().primaryKeyLength];
+            byte[] keyf;
+            try {
+                keyf = new byte[index.row().primaryKeyLength];
+            } catch (OutOfMemoryError e) {
+                throw new RowSpaceExceededException(index.row().primaryKeyLength, "HeapReader.get()/keyf");
+            }
             file.readFully(keyf, 0, keyf.length);
             if (!this.ordering.equal(key, keyf)) {
                 // verification of the indexed access failed. we must re-read the index
@@ -435,7 +441,12 @@ public class HeapReader {
             }
             
             // read the blob
-            byte[] blob = new byte[len];
+            byte[] blob;
+            try {
+                blob = new byte[len];
+            } catch (OutOfMemoryError e) {
+                throw new RowSpaceExceededException(len, "HeapReader.get()/blob");
+            }
             file.readFully(blob, 0, blob.length);
             
             return blob;
diff --git a/source/net/yacy/kelondro/blob/MapHeap.java b/source/net/yacy/kelondro/blob/MapHeap.java
index 401207639..b79dd85c0 100644
--- a/source/net/yacy/kelondro/blob/MapHeap.java
+++ b/source/net/yacy/kelondro/blob/MapHeap.java
@@ -177,7 +177,7 @@ public class MapHeap implements Map<byte[], Map<String, String>> {
         
         synchronized (this) {
             // remove from cache
-            cache.remove(key);
+            if (cache != null) cache.remove(key);
     
             // remove from file
             blob.delete(key);
diff --git a/source/net/yacy/kelondro/index/RowCollection.java b/source/net/yacy/kelondro/index/RowCollection.java
index 0526ce88a..76b86c9fc 100644
--- a/source/net/yacy/kelondro/index/RowCollection.java
+++ b/source/net/yacy/kelondro/index/RowCollection.java
@@ -276,8 +276,8 @@ public class RowCollection implements Iterable<Row.Entry>, Cloneable {
         if (allocram == 0) return;
         assert chunkcache.length < elements * rowdef.objectsize : "wrong alloc computation (1): elements * rowdef.objectsize = " + (elements * rowdef.objectsize) + ", chunkcache.length = " + chunkcache.length;
         assert allocram > chunkcache.length : "wrong alloc computation (2): allocram = " + allocram + ", chunkcache.length = " + chunkcache.length;
-        if (allocram > Integer.MAX_VALUE || !MemoryControl.request(allocram, true))
-        	throw new RowSpaceExceededException(allocram, "RowCollection grow");
+        if (allocram > Integer.MAX_VALUE || !MemoryControl.request(allocram + 32, true))
+        	throw new RowSpaceExceededException(allocram + 32, "RowCollection grow");
         try {
             final byte[] newChunkcache = new byte[(int) allocram]; // increase space
             System.arraycopy(chunkcache, 0, newChunkcache, 0, chunkcache.length);