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 237a584..51cb64d 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 e9fc53d..3010ed5 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 a74d3c5..1e8ec11 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 b84537f..f1f333d 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);
   }
   
   /**