Introduction Over the last 2 days I played with Clay because a certain Scott Hanselman posted about it. I found it to work mostly in VB.Net too apart from the anonymous types. That kinda intrigued me and I posted it on Stackoverflow but did not get a good answer yet. So then I contacted the VB-team via their blog. And I got a reply from Lucian Wischik Spec Lead for Visual Basic. The answer Hi Christiaan.

Introduction Yesterday I made a post about using [Clay with VB.Net][1]. Clay works but not all functionality we have in C# work in VB.Net, which is mildly frustrating. To see if I could find a solution I [posted a question on StackOverflow][2]. But no solution yet. The problem This works in C# dynamic c = new ClayFactory(); var plant = c.Plant(new {LatinName = "test"}); Console.WriteLine(plant.LatinName); Console.ReadLine();``` but this does not work in VB.Net ```vbnet Dim c As Object = New ClayFactory Dim plant = c.Plant(New With {.LatinName = "test"}) Console.WriteLine(plant.LatinName) Console.ReadLine()``` I get this error message in VB.Net: > Cannot close over byref parameter > &#8216;$arg1&#8217; referenced in lambda &#8221; I&#8217;m not 100% sure how to solve this if I can even solve it. I&#8217;m guessing the VB.Net implementation of anonymous types is slightly different. I get the error on this line: ```vbnet Dim plant = c.Plant(New With {.LatinName = "test"})``` I would appreciate if someone could explain this to me. The IL seems to be quit different. For VB the private field Latinname is this: > .field private initonly !T0 $LatinName For C# it is: > <code class="codespan">.field private initonly !'&lt;latinname&gt;j__TPar' '&lt;latinname&gt;i__Field'&lt;br /> .custom instance void [mscorlib]System.Diagnostics.DebuggerBrowsableAttribute::.ctor(valuetype [mscorlib]System.Diagnostics.DebuggerBrowsableState) = ( 01 00 00 00 00 00 00 00 ) &lt;/latinname&gt;&lt;/latinname&gt;</code> And the public method Get_LatinName is this. VB: > <code class="codespan">ce !T0 get_LatinName() cil managed&lt;br /> {&lt;br /> .custom instance void [mscorlib]System.Diagnostics.DebuggerNonUserCodeAttribute::.ctor() = ( 01 00 00 00 )&lt;br /> // Code size 11 (0xb)&lt;br /> .maxstack 1&lt;br /> .locals init (!T0 V_0)&lt;br /> IL_0000: ldarg.0&lt;br /> IL_0001: ldfld !0 class VB$AnonymousType_0`1::$LatinName&lt;br /> IL_0006: stloc.0&lt;br /> IL_0007: br.s IL_0009&lt;br /> IL_0009: ldloc.0&lt;br /> IL_000a: ret&lt;br /> } // end of method VB$AnonymousType_0`1::get_LatinName</code> C#: > <code class="codespan">.method public hidebysig specialname instance !'j__TPar'&lt;br /> get_LatinName() cil managed&lt;br /> {&lt;br /> // Code size 11 (0xb)&lt;br /> .maxstack 1&lt;br /> .locals init (!'j__TPar' V_0)&lt;br /> IL_0000: ldarg.0&lt;br /> IL_0001: ldfld !0 class 'f__AnonymousType0`1'j__TPar'&gt;::'i__Field'&lt;br /> IL_0006: stloc.0&lt;br /> IL_0007: br.s IL_0009&lt;br /> IL_0009: ldloc.0&lt;br /> IL_000a: ret&lt;br /> } // end of method 'f__AnonymousType0`1'::get_LatinName</code> And these are the main methods: VB: > <code class="codespan">.method public static void Main() cil managed&lt;br /> {&lt;br /> .entrypoint&lt;br /> .custom instance void [mscorlib]System.STAThreadAttribute::.ctor() = ( 01 00 00 00 )&lt;br /> // Code size 90 (0x5a)&lt;br /> .maxstack 7&lt;br /> .locals init ([0] object c,&lt;br /> [1] object plant,&lt;br /> [2] class VB$AnonymousType_0`1 VB$t_ref$S0,&lt;br /> [3] object[] VB$t_array$S0)&lt;br /> IL_0000: nop&lt;br /> IL_0001: newobj instance void [ClaySharp]ClaySharp.ClayFactory::.ctor()&lt;br /> IL_0006: stloc.0&lt;br /> IL_0007: ldloc.0&lt;br /> IL_0008: ldnull&lt;br /> IL_0009: ldstr "Plant"&lt;br /> IL_000e: ldc.i4.1&lt;br /> IL_000f: newarr [mscorlib]System.Object&lt;br /> IL_0014: stloc.3&lt;br /> IL_0015: ldloc.3&lt;br /> IL_0016: ldc.i4.0&lt;br /> IL_0017: ldstr "test"&lt;br /> IL_001c: newobj instance void class VB$AnonymousType_0`1::.ctor(!0)&lt;br /> IL_0021: stelem.ref&lt;br /> IL_0022: nop&lt;br /> IL_0023: ldloc.3&lt;br /> IL_0024: ldnull&lt;br /> IL_0025: ldnull&lt;br /> IL_0026: ldnull&lt;br /> IL_0027: call object [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.NewLateBinding::LateGet(object,&lt;br /> class [mscorlib]System.Type,&lt;br /> string,&lt;br /> object[],&lt;br /> string[],&lt;br /> class [mscorlib]System.Type[],&lt;br /> bool[])&lt;br /> IL_002c: call object [mscorlib]System.Runtime.CompilerServices.RuntimeHelpers::GetObjectValue(object)&lt;br /> IL_0031: stloc.1&lt;br /> IL_0032: ldloc.1&lt;br /> IL_0033: ldnull&lt;br /> IL_0034: ldstr "LatinName"&lt;br /> IL_0039: ldc.i4.0&lt;br /> IL_003a: newarr [mscorlib]System.Object&lt;br /> IL_003f: ldnull&lt;br /> IL_0040: ldnull&lt;br /> IL_0041: ldnull&lt;br /> IL_0042: call object [Microsoft.VisualBasic]Microsoft.VisualBasic.CompilerServices.NewLateBinding::LateGet(object,&lt;br /> class [mscorlib]System.Type,&lt;br /> string,&lt;br /> object[],&lt;br /> string[],&lt;br /> class [mscorlib]System.Type[],&lt;br /> bool[])&lt;br /> IL_0047: call object [mscorlib]System.Runtime.CompilerServices.RuntimeHelpers::GetObjectValue(object)&lt;br /> IL_004c: call void [mscorlib]System.Console::WriteLine(object)&lt;br /> IL_0051: nop&lt;br /> IL_0052: call string [mscorlib]System.Console::ReadLine()&lt;br /> IL_0057: pop&lt;br /> IL_0058: nop&lt;br /> IL_0059: ret&lt;br /> } // end of method Module1::Main</code> C#: > <code class="codespan">.method private hidebysig static void Main(string[] args) cil managed&lt;br /> {&lt;br /> .entrypoint&lt;br /> // Code size 299 (0x12b)&lt;br /> .maxstack 10&lt;br /> .locals init ([0] object c,&lt;br /> [1] object plant,&lt;br /> [2] class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo[] CS$0$0000)&lt;br /> IL_0000: nop&lt;br /> IL_0001: newobj instance void [ClaySharp]ClaySharp.ClayFactory::.ctor()&lt;br /> IL_0006: stloc.0&lt;br /> IL_0007: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site1'&lt;br /> IL_000c: brtrue.s IL_004c&lt;br /> IL_000e: ldc.i4.0&lt;br /> IL_000f: ldstr "Plant"&lt;br /> IL_0014: ldnull&lt;br /> IL_0015: ldtoken ConsoleApplication2.Program&lt;br /> IL_001a: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)&lt;br /> IL_001f: ldc.i4.2&lt;br /> IL_0020: newarr [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo&lt;br /> IL_0025: stloc.2&lt;br /> IL_0026: ldloc.2&lt;br /> IL_0027: ldc.i4.0&lt;br /> IL_0028: ldc.i4.0&lt;br /> IL_0029: ldnull&lt;br /> IL_002a: call class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo::Create(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags,&lt;br /> string)&lt;br /> IL_002f: stelem.ref&lt;br /> IL_0030: ldloc.2&lt;br /> IL_0031: ldc.i4.1&lt;br /> IL_0032: ldc.i4.1&lt;br /> IL_0033: ldnull&lt;br /> IL_0034: call class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo::Create(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags,&lt;br /> string)&lt;br /> IL_0039: stelem.ref&lt;br /> IL_003a: ldloc.2&lt;br /> IL_003b: call class [System.Core]System.Runtime.CompilerServices.CallSiteBinder [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.Binder::InvokeMember(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags,&lt;br /> string,&lt;br /> class [mscorlib]System.Collections.Generic.IEnumerable`1,&lt;br /> class [mscorlib]System.Type,&lt;br /> class [mscorlib]System.Collections.Generic.IEnumerable`1)&lt;br /> IL_0040: call class [System.Core]System.Runtime.CompilerServices.CallSite`1 class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt;::Create(class [System.Core]System.Runtime.CompilerServices.CallSiteBinder)&lt;br /> IL_0045: stsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site1'&lt;br /> IL_004a: br.s IL_004c&lt;br /> IL_004c: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site1'&lt;br /> IL_0051: ldfld !0 class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt;::Target&lt;br /> IL_0056: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1f__AnonymousType0`1',object&gt;&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site1'&lt;br /> IL_005b: ldloc.0&lt;br /> IL_005c: ldstr "test"&lt;br /> IL_0061: newobj instance void class 'f__AnonymousType0`1'::.ctor(!0)&lt;br /> IL_0066: callvirt instance !3 class [mscorlib]System.Func`4f__AnonymousType0`1',object&gt;::Invoke(!0,&lt;br /> !1,&lt;br /> !2)&lt;br /> IL_006b: stloc.1&lt;br /> IL_006c: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site2'&lt;br /> IL_0071: brtrue.s IL_00b6&lt;br /> IL_0073: ldc.i4 0x100&lt;br /> IL_0078: ldstr "WriteLine"&lt;br /> IL_007d: ldnull&lt;br /> IL_007e: ldtoken ConsoleApplication2.Program&lt;br /> IL_0083: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)&lt;br /> IL_0088: ldc.i4.2&lt;br /> IL_0089: newarr [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo&lt;br /> IL_008e: stloc.2&lt;br /> IL_008f: ldloc.2&lt;br /> IL_0090: ldc.i4.0&lt;br /> IL_0091: ldc.i4.s 33&lt;br /> IL_0093: ldnull&lt;br /> IL_0094: call class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo::Create(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags,&lt;br /> string)&lt;br /> IL_0099: stelem.ref&lt;br /> IL_009a: ldloc.2&lt;br /> IL_009b: ldc.i4.1&lt;br /> IL_009c: ldc.i4.0&lt;br /> IL_009d: ldnull&lt;br /> IL_009e: call class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo::Create(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags,&lt;br /> string)&lt;br /> IL_00a3: stelem.ref&lt;br /> IL_00a4: ldloc.2&lt;br /> IL_00a5: call class [System.Core]System.Runtime.CompilerServices.CallSiteBinder [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.Binder::InvokeMember(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags,&lt;br /> string,&lt;br /> class [mscorlib]System.Collections.Generic.IEnumerable`1,&lt;br /> class [mscorlib]System.Type,&lt;br /> class [mscorlib]System.Collections.Generic.IEnumerable`1)&lt;br /> IL_00aa: call class [System.Core]System.Runtime.CompilerServices.CallSite`1 class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt;::Create(class [System.Core]System.Runtime.CompilerServices.CallSiteBinder)&lt;br /> IL_00af: stsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site2'&lt;br /> IL_00b4: br.s IL_00b6&lt;br /> IL_00b6: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site2'&lt;br /> IL_00bb: ldfld !0 class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt;::Target&lt;br /> IL_00c0: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site2'&lt;br /> IL_00c5: ldtoken [mscorlib]System.Console&lt;br /> IL_00ca: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)&lt;br /> IL_00cf: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site3'&lt;br /> IL_00d4: brtrue.s IL_0109&lt;br /> IL_00d6: ldc.i4.0&lt;br /> IL_00d7: ldstr "LatinName"&lt;br /> IL_00dc: ldtoken ConsoleApplication2.Program&lt;br /> IL_00e1: call class [mscorlib]System.Type [mscorlib]System.Type::GetTypeFromHandle(valuetype [mscorlib]System.RuntimeTypeHandle)&lt;br /> IL_00e6: ldc.i4.1&lt;br /> IL_00e7: newarr [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo&lt;br /> IL_00ec: stloc.2&lt;br /> IL_00ed: ldloc.2&lt;br /> IL_00ee: ldc.i4.0&lt;br /> IL_00ef: ldc.i4.0&lt;br /> IL_00f0: ldnull&lt;br /> IL_00f1: call class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo::Create(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfoFlags,&lt;br /> string)&lt;br /> IL_00f6: stelem.ref&lt;br /> IL_00f7: ldloc.2&lt;br /> IL_00f8: call class [System.Core]System.Runtime.CompilerServices.CallSiteBinder [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.Binder::GetMember(valuetype [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpBinderFlags,&lt;br /> string,&lt;br /> class [mscorlib]System.Type,&lt;br /> class [mscorlib]System.Collections.Generic.IEnumerable`1)&lt;br /> IL_00fd: call class [System.Core]System.Runtime.CompilerServices.CallSite`1 class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt;::Create(class [System.Core]System.Runtime.CompilerServices.CallSiteBinder)&lt;br /> IL_0102: stsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site3'&lt;br /> IL_0107: br.s IL_0109&lt;br /> IL_0109: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site3'&lt;br /> IL_010e: ldfld !0 class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt;::Target&lt;br /> IL_0113: ldsfld class [System.Core]System.Runtime.CompilerServices.CallSite`1&gt; ConsoleApplication2.Program/'o__SiteContainer0'::'p__Site3'&lt;br /> IL_0118: ldloc.1&lt;br /> IL_0119: callvirt instance !2 class [mscorlib]System.Func`3::Invoke(!0,&lt;br /> !1)&lt;br /> IL_011e: callvirt instance void class [mscorlib]System.Action`3::Invoke(!0,&lt;br /> !1,&lt;br /> !2)&lt;br /> IL_0123: nop&lt;br /> IL_0124: call string [mscorlib]System.Console::ReadLine()&lt;br /> IL_0129: pop&lt;br /> IL_012a: ret&lt;br /> } // end of method Program::Main</code> The C# and VB version are nothing alike. Seems like the C# version does a lot more. So there goes the theory C# and VB.Net compile to the same IL. I also tried debugging Clay to see which line was causing the problem on their side. The problem is that it is building a whole expressiontree and that it is difficult to say where it actually fails. ```csharp public override DynamicMetaObject BindInvokeMember(InvokeMemberBinder binder, DynamicMetaObject[] args) { Logger.Log(LogLevel.Debug, null, "BindInvokeMember"); var argValues = Expression.NewArrayInit(typeof(object), args.Select(x =&gt; Expression.Convert(x.Expression, typeof(Object)))); var argNames = Expression.Constant(binder.CallInfo.ArgumentNames, typeof(IEnumerable&lt;string&gt;)); var argNamedEnumerable = Expression.Call(typeof(Arguments).GetMethod("From"), argValues, argNames); var binderDefault = binder.FallbackInvokeMember(this, args); var missingLambda = Expression.Lambda(Expression.Call( GetClayBehavior(), IClayBehavior_InvokeMemberMissing, Expression.Lambda(binderDefault.Expression), GetLimitedSelf(), Expression.Constant(binder.Name, typeof(string)), argNamedEnumerable)); var call = Expression.Call( GetClayBehavior(), IClayBehavior_InvokeMember, missingLambda, GetLimitedSelf(), Expression.Constant(binder.Name, typeof(string)), argNamedEnumerable); var dynamicSuggestion = new DynamicMetaObject( call, BindingRestrictions.GetTypeRestriction(Expression, LimitType).Merge(binderDefault.Restrictions)); return binder.FallbackInvokeMember(this, args, dynamicSuggestion); }``` I think it bombs out on the binder.FallBackInvokeMember. And that just invokes the expressiontree. But nothing on [MSDN seems to suggest][3] this is not compatible with VB.Net or that they have to be carefull about something. ## Conclusion For the moment I am at a lose if you know someone that can help then please do so. [1]: /index.php/DesktopDev/MSTech/using-clay-in-vb-net [2]: http://stackoverflow.com/questions/5922964/why-do-my-anonymous-types-not-work-in-clay-when-using-vb-net-but-do-work-in-c [3]: http://msdn.microsoft.com/en-us/library/dd466445.aspx

**Deleting OS files from a stored procedure: ** Here is one way to remove old backup files from the OS through a stored procedure. The procedure can be compiled in any database. Once compiled you can run the stored procedure from a scheduled job to remove old backup files from the OS. IF EXISTS (SELECT [name] FROM dbo.sysobjects WHERE [name] = 'usp_Delete_OS_Files_By_Date' AND TYPE = 'P') 

Introduction Today [Scott Hanselman][1] did a post about [NuGet Package of the Week #6 – Dynamic, Malleable, Enjoyable Expando Objects with Clay][2] and allthough Scott is slightly awesome, he is not awesome enough to add VB.Net samples. So I contacted him and asked if I could do that for him. And here I am. Clay I will refer you to Scott’s post on how to get Clay, it only takes seconds with Nuget.

Over the next month, with a few days change, LessThanDot will be posting, "DBA Tip a Day Series" for SQL Server Database Administrators. The hopes of this series of blogs and articles will be to assist anyone that is starting out in SQL Server and also DBAs with vested years of experience to gain more knowledge. The list of tips includes topics such as Memory, CPU, I/O, Baselines, Security Auditing, and even Professional Development. These will be tips, and not in-depth looks into each one. The tips will draw from crucial areas in the community, pulling information from many resources, to provide a comprehensive guide to finding answers.

Here is a quick demonstration that shows you what can happen when you use defaults that are much shorter than the value that is updated from an insert trigger. The ModifiedBy column has a default of " but in the trigger it gets updated to ‘SomeapplicationName used by ’ +SUSER_NAME(). Ideally you want the default to also be ‘SomeapplicationName used by ’ +SUSER_NAME() Let’s take a look, first create the following table

May 17th I have the distinct pleasure of presenting for one of the strongest SQL Server User Groups around; PASSMN (Minnesota SQL Server User Group). Visiting this user group has an added bonus of me being the Regional Mentor for the area. It isn’t very often I am able to attend in person the user groups that I stay in contact with for the mentorship program. I hope to use this to build more personal relationships with the groups. 

The Default Trace exists in SQL Server 2005 and higher versions, in all editions. The trace has been questioned: what is it, and why is it helpful? We will go over the answers to these questions and look into the Default Trace, showing how to use it to retrieve information it collects while enabled. What is the Default Trace? The Default Trace is a trace prepackaged into SQL Server and enabled by default when you install SQL Server. You cannot alter the events the Default Trace captures but can disable the trace by executing the following.

There are times in our careers where we have to branch out and learn more than just the next technology or tools. After a few years we find that the difference between junior and senior, getting by and excelling, is not just learning new technologies and tools, but also learning from our experiences and the experiences of others. For the next few weeks I’ll be posting book selections from my home shelves. This first book selection is for developers, with Architecture (software and business), Management (Project and People), and Data in upcoming posts.

Troubleshooting any type of problem can be stressful and tedious. SQL Server performance issues are no exception. If an instance of SQL Server suddenly shows a spike or immediate bottleneck with one or many resources, determining the cause of that spike can test any DBA’s patience. What can make troubleshooting a performance problem in SQL Server more confusing is the lack of a true baseline. A baseline can be any set of metrics that have been recorded about SQL Server. Baselines will show normal operating behavior and, more importantly, show a DBA a true problem verses a normal tasking effect of the usage of your database server.