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Changed by [EMAIL PROTECTED] http://bugzilla.ximian.com/show_bug.cgi?id=80075 --- shadow/80075 2006-11-28 11:13:58.000000000 -0500 +++ shadow/80075.tmp.13891 2006-11-28 11:13:58.000000000 -0500 @@ -0,0 +1,91 @@ +Bug#: 80075 +Product: Mono: Class Libraries +Version: 1.2 +OS: +OS Details: +Status: NEW +Resolution: +Severity: +Priority: Normal +Component: Sys.Data +AssignedTo: [EMAIL PROTECTED] +ReportedBy: [EMAIL PROTECTED] +QAContact: [EMAIL PROTECTED] +TargetMilestone: --- +URL: +Cc: +Summary: bad performance problem with access of datarow column + +Description of Problem: +When you access a datarow column, if the column name is not exactly (case +sensitive) the same the performances are very poor. + +Steps to reproduce the problem: +1. Try this test + + public static void Main() + { + + + DataTable dt=new DataTable(); + for (int i=0;i<100;i++) + { + dt.Columns.Add("nom_colonne"+i,typeof(string)); + } + for (int j=0;j<100;j++) + { + DataRow r=dt.NewRow(); + for (int k=0;k<10;k++) + { + r[k]=Guid.NewGuid().ToString(); + } + dt.Rows.Add(r); + } + DateTime debut=DateTime.Now; + foreach (DataRow thisDataRow in dt.Rows) + { + string s=""; + for (int i=0;i<dt.Columns.Count;i++) + { + string index="NOM_COLONNE"+i; + s+=thisDataRow[index].ToString(); + + } + + } + DateTime fin=DateTime.Now; + TimeSpan dure=fin-debut; + Console.WriteLine("Durée :"+dure); + + + } + + +Actual Results: +Execution time : 12s + +If you replace : +string index="NOM_COLONNE"+i; +by +string index="nom_colonne"+i; + +you get +:0.166ms + +(one hundred times faster!) + + +Expected Results: +On MS.NET you get : + +0.125 (in the worse case) (MS.NET is 100x faster than mono in this case) +and +0.062 (in the best case) (MS.NET is only 2x faster than mono) + + + + +How often does this happen? +always + +Additional Information:
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