I am getting an Exception in thread "HSQLDB Connection @3c50507" java.lang.OutOfMemoryError: Java heap space, when running a JSP. what is the thing that is out of memory? eclipse, HSQLDB or Tomcat?? i am using all that in a Mac OS X 10.7.4 When i start HSQLDB, then i get by console this exception: [Server@122ce908]: From command line, use [Ctrl]+[C] to abort abruptly Exception in thread "HSQLDB Connection @2e716cb7" java.lang.OutOfMemoryError: Java heap space at org.hsqldb.lib.HsqlByteArrayOutputStream.ensureRoom(Unknown Source) at org.hsqldb.rowio.RowOutputBinary.ensureRoom(Unknown Source) at org.hsqldb.lib.HsqlByteArrayOutputStream.write(Unknown Source) at org.hsqldb.rowio.RowOutputBinary.writeByteArray(Unknown Source) at org.hsqldb.rowio.RowOutputBinary.writeBinary(Unknown Source) at org.hsqldb.rowio.RowOutputBase.writeData(Unknown Source) at org.hsqldb.Result.write(Unknown Source) at org.hsqldb.Result.write(Unknown Source) at org.hsqldb.ServerConnection.run(Unknown Source) at java.lang.Thread.run(Thread.java:680) What does this all mean?