denouter.net

Snow Leopard takes too long to sleep (not anymore)

2010-02-08T20:15:00.006+01:00

Usually it takes my iMac about 1 or 2 seconds to sleep (hibernate). Today it took about 25 seconds. I turned off my mac, started it again, but still it took about 25 seconds to sleep.

You can use the command pmset -g log to figure out whats happening when the mac goes to sleep. In my case I noticed an "applicationresponse.timedout" in this log for the process cupsd. This is the printer-deamon. Viewing the status of my printer I noticed a document I printed yesterday, which hasn't come out because the printer ran out of paper. Removing this item from the print-queue resulted back in a mac which went to sleep in 1-2 seconds.

ORA-06413 Connection not open.

2010-01-29T15:04:00.004+01:00

I'd moved the source files from a c# .net application on my filesystem. When I openened the solution in VS2008 and started it I got the following error "ORA-06413 Connection not open."

Solution to this problem: One of my folders had an opening parenthesis "(". Removing this parenthesis solved the problem!

Dag MCE, hallo XBMC !

2010-01-18T07:27:00.001+01:00

Ik gebruikte Windows XP MCE al voor een tijdje voor het afspelen van mijn media. Mooie hiervan was dat ook uitzending gemist via online spotlight benaderbaar was. Tot voorkort ... Ineens gaf het de melding dat dit niet gesupporteerd was. Bij het volgen van de help kwam ik op een MS-website die mij doodleuk meldde dat ik moest upgraden naar Windows 7 ! Dit houdt voor mij in dat ik ook mijn hardware moet upgraden; dus niet!

Ik ben via Plex voor de Mac terecht gekomen op de site van XBMC en door middel van deze plugin kan ik gewoon uitzendinggemist kijken op mijn "oude" mediacenter. Het is met XBMC niet mogelijk om programma's op te nemen via een TV kaart, maar het doet verder niet onder voor MCE. Tevens zijn er veel plugins verkrijgbaar op deze site.

.Net Application on a network share

2009-11-06T13:38:00.005+01:00

I'd developed a .net framework 2.0 winform application for a customer which had to be started on a client pc from a network share. I'd already had framework 3.5 sp1 on my machine, but with setting the .net target right I thought I made solid solution.

The customer could not start it. They got a System.Security.Security exception when starting the application on a client with .net framework 2.0 from the network. When copying the application on the client machine first, it started with no problems.

On clients which already had framework 3.5 sp1 there was no problem starting the application from the network share.

The answer lies in some sort of trust policies, which are changed (or gone) on framework 3.5

By giving the share full trust of the client:

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\caspol.exe -m -ag 1 -url "file:////\\computername\sharename\*" FullTrust -exclusive on

The application can be started on a client with .net framework 2.0 from a network share.

NOTE: do not run this command twice on the same computer, the full trust does not work anymore!

Rabobank Overview

2009-09-24T21:10:00.000+02:00

Om een duidelijk overzicht te krijgen van de in- en uitgaven in de maand heb ik een programmaatje gemaakt die aan de hand van Rabobank internet bankieren een overzicht maakt van de in- en uitgaven.

Ook is het mogelijk om binnen de transacties te zoeken en mutaties "af te vinken".
Meer informatie vind je in de snel start gids.

Start de applicatie

Guid.comb and synchronization

2009-06-23T13:40:00.004+02:00

Synchronize an entity between two databases.

I had set up this records with a GUID and used the guid.comb from NHibernate to generate these for me.
Then I needed to synchronize this object with an other database.

Using NHibernate, just create a new session, evict the object from the first one, and save it the next one. No problem, except a new GUID was generated....

My assumption was that an entity with a guid.com generated GUID kept its value. I was wrong.

The answer lies in the ISession.Replicate. This allowes me to copy an entity from one session to another witout losing the generated key.

  foreach (var person in persons)
  {
      sourceSession.Evict(person);
      targetSession.Replicate(person, ReplicationMode.Overwrite);
  }
  targetSession.Flush();

The ReplicationMode lets you choose the behaviour (Overwrite, LatestVersion, Ignore etc.)

Linq To NHibernate

2009-06-18T07:31:00.002+02:00

Compile your queries

One of the hardest things to do with a database application (e.g. a c# WinForm) is to create all the queries in your app. Where to put them in the model? Use queries, or make stored procedures on the database etc etc.
Then creating all these queries in your code as strings;

"SELECT name, age, .. FROM ..."

This is a lot of work and causes runtime errors because these queries aren't checked at compile-time. Then there are issues of caching, relational data, locking etc etc. All these issues can be solved by NHibernate. This framework maps your OO-Model to your relational model and creates the queries, relations, locking etc for you.
But still there are these runtime errors which may occur, because even a Criteria/Expression in NHibernate uses strings as properties.


  .Add(Expression.Like("Title", "Linq To%"))

This can be solved using Linq To NHibernate. This extension to the ISession creates an IQueriable which uses the intellisense of Visual Studio


var q = from tasks in session.Linq<task>()
      where tasks.Title.StartsWith("Linq To")
      select tasks;

Linq To NHibernate also eases creating queries with multiple joins:


var q = from tasks in session.Linq<task>()
      where tasks.Owner.Address.City == "Dalem"
      select tasks;

I find Linq To NHibernate a great help with developing my database applications.

Optimize SQL Server 2005 Procedures

2009-03-13T20:19:00.011+01:00

I had a stored procedure which took about 3 minutes to run, but starting this query in the management studio of sql server took 2 seconds! The problem lies in the "parameter sniffing". Google it for the exact cause, but copying the parameter variables to local variables within the procedure like the example below does the trick.

Slow procedure:


CREATE PROCEDURE GetMeMyData
@param1 NVARCHAR(20)
AS
BEGIN
SELECT id, name, otherstuff
FROM dbo.table1
WHERE param1 = @param1
END

Fast procedure:


CREATE PROCEDURE GetMeMyData
@param1 NVARCHAR(20)
AS
BEGIN
DECLARE @localParam1 NVARCHAR(20)
SET @localParam1 = @param1
SELECT id, name, otherstuff
FROM dbo.table1
WHERE param1 = @localParam1
END

At first I tought it had something to do with an outdated version of SQL Server, but it even occurs on SQL Server 2005 SP3.

Fast Clone

2009-02-26T20:45:00.007+01:00

Ever had to make a in memory copy of a simple object? You then have to copy each property or create an IClonable implentation. Just like the simple reflection form you can use reflection to create a fast clone.
Just call the static method FastClone.Clone:


Customer c = new Customer
{
Id = Guid.NewGuid(),
Name = "Frank",
Age = 31,
Married = true
};

Customer c2 = (Customer)FastClone.Clone(c, "Id");

Optionally properties can be given to exclude from the clone.
You can download the source of FastClone here.

Enjoy!

Arithmetic Abort Enabled

2008-12-19T05:54:00.002+01:00

I have a stored procedure in SQL Server 2005 which takes a lot of a time to run from my .Net 2.0 Framework application and sometimes even gives a "Timeout expired".
Executing the same stored procedure in SQL Server Management Studio gives the result in less than 2 seconds! Why??

The answer lays in one single setting. When SQL Server Management Studio connects to the database it sets the "Arithmetic Abort Enabled" on. This option triggers the database to create new executions plans for the stored procedures.

Setting this option improved the performance of my .Net 2.0 Framework application!

Simple reflection form

2008-08-05T06:00:00.008+02:00

Haven't you had some poco's (plain old CLR object) you just want to edit, but you had to make a form for each object?

The solution to this is dot net's reflection. The SimpleReflectionForm takes an object like the Customer below and shows this in a form.


public class Customer
{
   public Guid Id { get; set; }
   public string Name { get; set; }
   public int Age { get; set; }
   public bool Married { get; set; }
}

Just call the form:


Customer c = new Customer
{
 Id = Guid.NewGuid(),
 Name = "Frank",
 Age = 31,
 Married = true
};

using (SimpleReflectionForm f
    = new SimpleReflectionForm(c, "Id"))
{
  f.ShowDialog();
}

The following form is shown:

As you can see the Id is ignored, by the optional parameter string[] propertiesToExclude.
The form supports all native .net types (int, string, datetime, guid etc). Guid and numeric types are verified when the Ok button is pressed.

You can download the source of SimpleReflectionForm here.

Enjoy!

UNION with DISTINCT via ODBC to ORACLE

2008-08-04T20:15:00.002+02:00

In a VBA application (MS Access XP) with linked tables to Oracle the following query completely crashes Access!


SELECT A1.V_ID, A1.PR_ID, A1.AREA_ID, A1.TYPE,
 A1.AREA, A1.AREA_MAIN_ID, A1.ACTIVE
FROM AREAS AS A1
UNION SELECT DISTINCT A2.V_ID, A2.PR_ID,
-1 AS AREA_ID, A2.TYPE, '' AS AREA,
A2.AREA_MAIN_ID, -1 AS ACTIVE
FROM AREAS AS  A2;

Solution: convert the distinct to a group by


SELECT A1.V_ID, A1.PR_ID, A1.AREA_ID, A1.TYPE,
A1.AREA, A1.AREA_MAIN_ID, A1.ACTIVE
FROM AREAS AS  A1
UNION (
SELECT A2.V_ID, A2.PR_ID, -1 AS AREA_ID, A2.TYPE,
'' AS AREA, A2.AREA_MAIN_ID, -1 AS ACTIVE
FROM AREAS AS A2
GROUP BY A2.V_ID, A2.PR_ID, A2.TYPE, A2.AREA_MAIN_ID);

Enable & disable foreign keys in Oracle

2008-07-24T18:15:00.006+02:00


CREATE OR REPLACE PROCEDURE DIS_FK_CONSTR as
CURSOR c iS
SELECT CONSTRAINT_NAME, TABLE_NAME
FROM user_constraints
WHERE CONSTRAINT_TYPE = 'R' AND STATUS = 'ENABLED';

BEGIN
FOR i IN c LOOP
EXECUTE IMMEDIATE 'ALTER TABLE ' || i.TABLE_NAME ||
' DISABLE CONSTRAINT ' || i.CONSTRAINT_NAME;
END LOOP;

END DIS_FK_CONSTR;
/


CREATE OR REPLACE PROCEDURE ENA_FK_CONSTR as
CURSOR c iS
SELECT CONSTRAINT_NAME, TABLE_NAME
FROM user_constraints
WHERE CONSTRAINT_TYPE = 'R' AND STATUS = 'DISABLED';

BEGIN
FOR i IN c LOOP
EXECUTE IMMEDIATE 'ALTER TABLE ' || i.TABLE_NAME ||
' ENABLE CONSTRAINT ' || i.CONSTRAINT_NAME;
END LOOP;

END ENA_FK_CONSTR;
/