--- a/src/main/java/nl/cwi/monetdb/mcl/connection/mapi/AbstractSocket.java
+++ b/src/main/java/nl/cwi/monetdb/mcl/connection/mapi/AbstractSocket.java
@@ -52,11 +52,11 @@ public abstract class AbstractSocket imp
     AbstractSocket(String hostname, int port, MapiConnection connection) throws IOException {
         this.socket = new Socket(hostname, port);
         this.connection = connection;
-        this.bufferIn = ByteBuffer.wrap(new byte[getBlockSize()]);
-        this.bufferOut = ByteBuffer.wrap(new byte[getBlockSize()]);
-        this.stringsDecoded = CharBuffer.allocate(getBlockSize());
+        this.bufferIn = ByteBuffer.wrap(new byte[getFullBlockSize()]);
+        this.bufferOut = ByteBuffer.wrap(new byte[getFullBlockSize()]);
+        this.stringsDecoded = CharBuffer.allocate(getFullBlockSize());
         this.stringsDecoded.flip();
-        this.stringsEncoded = CharBuffer.allocate(getBlockSize());
+        this.stringsEncoded = CharBuffer.allocate(getFullBlockSize());
     }
 
     /**
@@ -100,6 +100,13 @@ public abstract class AbstractSocket imp
     }
 
     /**
+     * Gets the underlying socket full block size.
+     *
+     * @return The underlying socket full block size
+     */
+    public abstract int getFullBlockSize();
+
+    /**
      * Gets the underlying socket block size.
      *
      * @return The underlying socket block size
@@ -134,7 +141,7 @@ public abstract class AbstractSocket imp
      *
      * @throws IOException If an error in the underlying connection happened
      */
-    private void readToBuffer() throws IOException {
+    private void readToInputBuffer() throws IOException {
         int read = this.readToBufferIn(this.bufferIn);
         if(read == 0) {
             throw new IOException("The server has reached EOF!");
@@ -158,15 +165,18 @@ public abstract class AbstractSocket imp
         boolean found = false;
         char[] sourceArray = this.stringsDecoded.array();
         int sourcePosition = this.stringsDecoded.position();
+        int sourceLimit = this.stringsDecoded.limit();
         char[] destinationArray = lineBuffer.array();
         int destinationPosition = 0;
         int destinationLimit = lineBuffer.limit();
 
         while(!found) {
-            if(!this.stringsDecoded.hasRemaining()) {
-                this.readToBuffer();
+            if(sourcePosition >= sourceLimit) {
+                this.stringsDecoded.position(sourcePosition);
+                this.readToInputBuffer();
                 sourceArray = this.stringsDecoded.array();
                 sourcePosition = 0;
+                sourceLimit = this.stringsDecoded.limit();
             }
             char c = sourceArray[sourcePosition++];
             if(c == '\n') {
@@ -189,9 +199,10 @@ public abstract class AbstractSocket imp
     /**
      * Helper method to write, encode into UTF-8 and flush.
      *
+     * @param toFlush A boolean indicating to flush the underlying stream or not
      * @throws IOException If an error in the underlying connection happened
      */
-    private void flushOutputCharBuffer() throws IOException {
+    private void writeToOutputBuffer(boolean toFlush) throws IOException {
         this.stringsEncoded.flip();
         this.utf8Encoder.reset();
         this.utf8Encoder.encode(this.stringsEncoded, this.bufferOut, true);
@@ -201,23 +212,28 @@ public abstract class AbstractSocket imp
         if(written == 0) {
             throw new IOException("The query could not be sent to the server!");
         } else {
-            this.flush();
+            if(toFlush) {
+                this.flush();
+            }
         }
     }
 
     /**
      * Writes a String line into the underlying socket.
      *
+     * @param line The line to write in the socket
      * @throws IOException If an error in the underlying connection happened
      */
     private void writeNextBlock(String line) throws IOException {
         int limit = line.length();
         int destinationPosition = this.stringsEncoded.position();
+        int destinationCapacity = this.stringsEncoded.capacity();
         char[] destinationArray = this.stringsEncoded.array();
 
         for (int i = 0; i < limit; i++) {
-            if (!this.stringsEncoded.hasRemaining()) {
-                this.flushOutputCharBuffer();
+            if (destinationPosition >= destinationCapacity) {
+                this.stringsEncoded.position(destinationPosition);
+                this.writeToOutputBuffer(false);
                 destinationArray = this.stringsEncoded.array();
                 destinationPosition = 0;
             }
@@ -242,9 +258,6 @@ public abstract class AbstractSocket imp
         if(suffix != null) {
             this.writeNextBlock(suffix);
         }
-        this.writeNextBlock("\n");
-        if (this.stringsEncoded.hasRemaining()) {
-            this.flushOutputCharBuffer();
-        }
+        this.writeToOutputBuffer(true);
     }
 }

--- a/src/main/java/nl/cwi/monetdb/mcl/connection/mapi/OldMapiSocket.java
+++ b/src/main/java/nl/cwi/monetdb/mcl/connection/mapi/OldMapiSocket.java
@@ -36,8 +36,11 @@ import java.nio.ByteBuffer;
  */
 public class OldMapiSocket extends AbstractSocket {
 
+    /** The full blocksize to use in the upper layer buffers */
+    public final static int FULL_BLOCK = 8 * 1024;
+
     /** The blocksize (hardcoded in compliance with stream.mx) */
-    public final static int BLOCK = 8 * 1024 - 2;
+    private static final int BLOCK = FULL_BLOCK - 2;
 
     /**
      * A short in two bytes for holding the block size in bytes.
@@ -61,6 +64,14 @@ public class OldMapiSocket extends Abstr
     }
 
     /**
+     * The block size to be used in the upper layer buffers
+     */
+    @Override
+    public int getFullBlockSize() {
+        return FULL_BLOCK;
+    }
+
+    /**
      * The block size will be the one hardcoded on the connection.
      */
     @Override
@@ -99,7 +110,7 @@ public class OldMapiSocket extends Abstr
 
         private int blockLen = 0;
 
-        private final byte[] block = new byte[BLOCK];
+        private final byte[] block = new byte[BLOCK + 3]; //\n.\n
 
         /**
          * Constructs this BlockInputStream, backed by the given InputStream. A BufferedInputStream is internally used.
@@ -182,7 +193,6 @@ public class OldMapiSocket extends Abstr
                 block[blockLen++] = MapiConnection.PROMPT_CHAR;
                 block[blockLen++] = '\n';
             }
-
             return blockLen;
         }
 
@@ -319,7 +329,6 @@ public class OldMapiSocket extends Abstr
 
         int write(ByteBuffer b, int off, int len) throws IOException {
             int t, written = 0;
-            b.flip();
             while (len > 0) {
                 t = BLOCK - writePos;
                 if (len > t) {

--- a/src/main/java/nl/cwi/monetdb/mcl/protocol/oldmapi/OldMapiProtocol.java
+++ b/src/main/java/nl/cwi/monetdb/mcl/protocol/oldmapi/OldMapiProtocol.java
@@ -59,7 +59,7 @@ public class OldMapiProtocol extends Abs
 
     public OldMapiProtocol(OldMapiSocket socket) {
         this.socket = socket;
-        this.lineBuffer = CharBuffer.wrap(new char[OldMapiSocket.BLOCK]);
+        this.lineBuffer = CharBuffer.wrap(new char[OldMapiSocket.FULL_BLOCK]);
         this.tupleLineBuffer = CharBuffer.wrap(new char[TUPLE_LINE_BUFFER_DEFAULT_SIZE]);
     }
 
@@ -267,7 +267,7 @@ public class OldMapiProtocol extends Abs
      * @throws IOException If an error in the underlying connection happened.
      */
     @Override
-    public synchronized void writeNextQuery(String prefix, String query, String suffix) throws IOException {
+    public void writeNextQuery(String prefix, String query, String suffix) throws IOException {
         this.socket.writeNextLine(prefix, query, suffix);
         // reset reader state, last line isn't valid any more now
         this.currentServerResponseHeader = ServerResponses.UNKNOWN;