Attached are patches for two fixes to reduce memory usage by the JDBC

drivers.

The first fix fixes the PreparedStatement object to not allocate
unnecessary objects when converting native types to Stings.  The old
code used the following format:
        (new Integer(x)).toString()
whereas this can more efficiently be occompilshed by:
        Integer.toString(x);
avoiding the unnecessary object creation.

The second fix is to release some resources on the close() of a
ResultSet.  Currently the close() method on ResultSet is a noop.  The
purpose of the close() method is to release resources when the ResultSet
is no longer needed.  The fix is to free the tuples cached by the
ResultSet when it is closed (by clearing out the Vector object that
stores the tuples).  This is important for my application, as I have a
cache of Statement objects that I reuse.  Since the Statement object
maintains a reference to the ResultSet and the ResultSet kept references
to the old tuples, my cache was holding on to a lot of memory.

Barry Lind

diff --git a/src/interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java b/src/interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java
index 237a58486d8d77e26c7bddc8ba57598dc24fcb63..51cb64d5a218e9893990c864da73dac9c14705fe 100644 (file)
--- a/src/interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java
+++ b/src/interfaces/jdbc/org/postgresql/jdbc1/PreparedStatement.java
@@ -164,7 +164,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setByte(int parameterIndex, byte x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -177,7 +177,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setShort(int parameterIndex, short x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -190,7 +190,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setInt(int parameterIndex, int x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -203,7 +203,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setLong(int parameterIndex, long x) throws SQLException
        {
-               set(parameterIndex, (new Long(x)).toString());
+               set(parameterIndex, Long.toString(x));
        }
 
        /**
@@ -216,7 +216,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setFloat(int parameterIndex, float x) throws SQLException
        {
-               set(parameterIndex, (new Float(x)).toString());
+               set(parameterIndex, Float.toString(x));
        }
 
        /**
@@ -229,7 +229,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setDouble(int parameterIndex, double x) throws SQLException
        {
-               set(parameterIndex, (new Double(x)).toString());
+               set(parameterIndex, Double.toString(x));
        }
 
        /**

diff --git a/src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java b/src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java
index e9fc53d96a85bec33dd6fda20557fdff34ebf5f1..3010ed59a3fbc98e478686d352dc5217e579e419 100644 (file)
--- a/src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java
+++ b/src/interfaces/jdbc/org/postgresql/jdbc1/ResultSet.java
@@ -127,7 +127,8 @@ public class ResultSet extends org.postgresql.ResultSet implements java.sql.Resu
    */
   public void close() throws SQLException
   {
-    // No-op
+    //release resources held (memory for tuples)
+    rows.setSize(0);
   }
   
   /**

diff --git a/src/interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java b/src/interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java
index a74d3c57b3cc3a637368b2e0f6aea9598ac7dc57..1e8ec1138ea8f10da6a51c5ed024deafb4f09520 100644 (file)
--- a/src/interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java
+++ b/src/interfaces/jdbc/org/postgresql/jdbc2/PreparedStatement.java
@@ -164,7 +164,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setByte(int parameterIndex, byte x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -177,7 +177,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setShort(int parameterIndex, short x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -190,7 +190,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setInt(int parameterIndex, int x) throws SQLException
        {
-               set(parameterIndex, (new Integer(x)).toString());
+               set(parameterIndex, Integer.toString(x));
        }
 
        /**
@@ -203,7 +203,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setLong(int parameterIndex, long x) throws SQLException
        {
-               set(parameterIndex, (new Long(x)).toString());
+               set(parameterIndex, Long.toString(x));
        }
 
        /**
@@ -216,7 +216,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setFloat(int parameterIndex, float x) throws SQLException
        {
-               set(parameterIndex, (new Float(x)).toString());
+               set(parameterIndex, Float.toString(x));
        }
 
        /**
@@ -229,7 +229,7 @@ public class PreparedStatement extends Statement implements java.sql.PreparedSta
         */
        public void setDouble(int parameterIndex, double x) throws SQLException
        {
-               set(parameterIndex, (new Double(x)).toString());
+               set(parameterIndex, Double.toString(x));
        }
 
        /**

diff --git a/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java b/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
index b84537fb4532f28984956b17657ddbc75464d2ef..f1f333d6d2fb42307e07a99d544d349a5a0f211d 100644 (file)
--- a/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
+++ b/src/interfaces/jdbc/org/postgresql/jdbc2/ResultSet.java
@@ -128,7 +128,8 @@ public class ResultSet extends org.postgresql.ResultSet implements java.sql.Resu
    */
   public void close() throws SQLException
   {
-    // No-op
+    //release resources held (memory for tuples)
+    rows.setSize(0);
   }
   
   /**