CacheSize Property Example (VJ++)

This example uses the CacheSize property to show the difference in performance for an operation performed with and without a 30-record cache.

// BeginCacheSizeJ
import com.ms.wfc.data.*;
import java.io.* ;

public class CacheSizeX
{
   // The main entry point for the application.

   public static void main (String[] args)
   {
      CacheSizeX();
      System.exit(0);
   }

   // CacheSizeX function

   static void CacheSizeX()
   {

      // Define ADO Objects.
      Recordset rstRoySched = null;

      // Declarations.
      BufferedReader in =
         new BufferedReader (new InputStreamReader(System.in));
      String line = null;
      String strCnn = "Provider='sqloledb';Data Source='MySqlServer';"
         + "Initial Catalog='Pubs';Integrated Security='SSPI';";

      long timeStart;
      long timeEnd;
      float timeNoCache;
      float timeCache;
      int   intLoop;
      String strTemp;

      try
      {
         // Open the RoySched table.
         rstRoySched = new Recordset();
         rstRoySched.open("roysched", strCnn,
            AdoEnums.CursorType.FORWARDONLY,
            AdoEnums.LockType.READONLY,
            AdoEnums.CommandType.TABLE);

         // Enumerate the Recordset object twice and record
         // the elapsed time.

         timeStart = System.currentTimeMillis();
         for ( intLoop = 0; intLoop < 2; intLoop++)
         {
            rstRoySched.moveFirst();
            while (!rstRoySched.getEOF())
            {
               // Execute a simple operation for the
               // performance test.
               strTemp = rstRoySched.getField("title_id").getString();
               rstRoySched.moveNext();
            }

         }

         timeEnd = System.currentTimeMillis();
         timeNoCache =(float)(timeEnd - timeStart)/1000f;

         // Cache records in groups of 30 records.
         rstRoySched.moveFirst();
         rstRoySched.setCacheSize(30);
         timeStart = System.currentTimeMillis();

         // Enumerate the Recordset object twice and record
         // the elapsed time.
         for ( intLoop = 0; intLoop < 2; intLoop++)
         {
            rstRoySched.moveFirst();
            while (!rstRoySched.getEOF())
            {
               // Execute a simple operation for the
               // performance test.

               strTemp = rstRoySched.getField("title_id").getString();
               rstRoySched.moveNext();
            }

         }

         timeEnd = System.currentTimeMillis();
         timeCache = (float)(timeEnd - timeStart)/1000f;

         // Display performance results.
         System.out.println("\nCaching Performance Results:");
         System.out.println("\n\tNo Cache: " + timeNoCache + " seconds");
         System.out.println("\n\t30-record cache: " + timeCache +
            " seconds");
         System.out.println("\n\nPress <Enter> to continue..");
         in.readLine();

      }
      catch( AdoException ae )
      {
         // Notify user of any errors that result from ADO.

         // Check for null pointer for connection object.
         if (rstRoySched.getActiveConnection()==null)
            System.out.println("Exception: " + ae.getMessage());

         // As passing a Recordset, check for null pointer first.
         if (rstRoySched != null)
         {
            PrintProviderError(rstRoySched.getActiveConnection());
         }
         else
         {
            System.out.println("Exception: " + ae.getMessage());
         }
      }

      // System read requires this catch.
      catch( java.io.IOException je)
      {
         PrintIOError(je);
      }
      finally
      {
         // Cleanup objects before exit.   
         if (rstRoySched != null)
            if (rstRoySched.getState() == 1)
               rstRoySched.close();
      }

   }

   // PrintProviderError Function

   static void PrintProviderError( Connection Cnn1 )
   {
      // Print Provider errors from Connection object.
      // ErrItem is an item object in the Connections Errors collection.
      com.ms.wfc.data.Error  ErrItem = null;
      long nCount = 0;
      int  i      = 0;

      nCount = Cnn1.getErrors().getCount();

      // If there are any errors in the collection, print them.
      if( nCount > 0);
      {
         // Collection ranges from 0 to nCount - 1
         for (i = 0; i< nCount; i++)
         {
            ErrItem = Cnn1.getErrors().getItem(i);
            System.out.println("\t Error number: " + ErrItem.getNumber()
               + "\t" + ErrItem.getDescription() );
         }
      }

   }

   // PrintIOError Function

   static void PrintIOError( java.io.IOException je)
   {
      System.out.println("Error \n");
      System.out.println("\tSource = " + je.getClass() + "\n");
      System.out.println("\tDescription = " + je.getMessage() + "\n");
   }
}

// EndCacheSizeJ

See Also

CacheSize Property | Recordset Object