The transaction log for database 'WebDB' is full.  No, it isn't. Its 90% free. The transaction log backups run normally. My hardware guy tells me the hardware is running perfectly, with plenty of space. SQL Server 2008 SP3, but not R2.  I'm a developer, we no longer have a DBA. So it falls to me to try and fix this.
Batch jobs error emails report:      The transaction log for database 'WebDB' is full.   No, it isn't. Its 90% free. The transaction log backups run normally. My hardware guy tells me the hardware is running perfectly, with plenty of space. SQL Server 2008 SP3, but not R2.  I'm a developer, we no longer have a DBA. So it falls to me to try and fix this.
System of linear equations having a real solution has also a rational solution. We can write Bayes' theorem as  $$p(\theta|x) = \frac{f(X|\theta)p(\theta)}{\int_{\theta} f(X|\theta)p(\theta)d\theta}$$  where $p(\theta|x)$ is the posterior, $f(X|\theta)$ is the conditional distribution, and $p(\theta)$ is the prior.  or  $$p(\theta|x) = \frac{L(\theta|x)p(\theta)}{\int_{\theta} L(\theta|x)p(\theta)d\theta}$$  where $p(\theta|x)$ is the posterior, $L(\theta|x)$ is the likelihood function, and $p(\theta)$ is the prior.  My question is   Why is Bayesian analysis done using the likelihood function and not the conditional distribution? Can you say in words what the difference between the likelihood and conditional distribution is?  I know the likelihood is not a probability distribution and $L(\theta|x) \propto f(X|\theta)$. Are GUID collisions possible? I'm working on a database in SQL Server 2000 that uses a GUID for each user that uses the app it's tied to. Somehow, two users ended up with the same GUID. I know that microsoft uses an algorithm to generate a random GUID that has an extremely low chance of causing collisons, but is a collision still possible? How to loop through all the properties of a class? I have a class.  Public Class Foo     Private _Name As String     Public Property Name() As String         Get             Return _Name         End Get         Set(ByVal value As String)             _Name = value         End Set     End Property      Private _Age As String     Public Property Age() As String         Get             Return _Age         End Get         Set(ByVal value As String)             _Age = value         End Set     End Property      Private _ContactNumber As String     Public Property ContactNumber() As String         Get             Return _ContactNumber         End Get         Set(ByVal value As String)             _ContactNumber = value         End Set     End Property   End Class   I want to loop through the properties of the above class. eg;  Public Sub DisplayAll(ByVal Someobject As Foo)     For Each _Property As something In Someobject.Properties         Console.WriteLine(_Property.Name &amp; "=" &amp; _Property.value)     Next End Sub In a multiple linear regression, why is it possible to have a highly significant F statistic (p&lt;.001) but have very high p-values on all the regressor's t tests?  In my model, there are 10 regressors. One has a p-value of 0.1 and the rest are above 0.9    For dealing with this problem see the . Add warning when changing display name The policy on changing one's display name :  only one display name change is allowed every 30 days  However, there is no warning whatsoever when actually changing one's display name.  Thus, it came as quite a bit of a shock to me when I found out today that I might be stuck as &quot;Unicorns are Yummy&quot; on Stack Overflow for the next freakin' month. I would like to recommend that a warning be added to the &quot;Edit Profile&quot; page to warn people. Or, at least make the policy concerning display name changes more obvious. Workaround I was able to change my display name back (phew!) by copying my profile from Meta Stack Overflow. I still think a warning should be implemented, though. I forgot my password of a TrueCrypt file I used a few years ago.  How would I go about 'cracking' it? I'm not sure if there is a way to attack it or if it can only be done by brute-force. I used it on a Mac. I still have the Mac I used it on, but of course turned that off many times since I used it.   I have a passphrase that I thought would relate to this file. Maybe I used some variant of it. But might be something completely different. I have some other words that I might have used, but would need give it another thought how I could have used those.  Is there an automated way to test variations on what I think the passphrase was to regain access to the volume? Is there any other way I might regain access? Could we send a man safely to the Moon in a rocket without knowledge of general relativity? For an affine connection $\nabla$, prove the curvature R  $R(X,Y,Z,\alpha)=\alpha(\nabla_X \nabla_Y Z - \nabla_Y \nabla_X Z -\nabla_{[X,Y]}Z)$  with $X,Y,Z$ vector fields and $\alpha$ a co-vector, is a tensor.  So I realise the aim is probably to show that each of the three terms in the expression for $R$ are tensors themselves as then the result will obviously follow. However, I'm not too sure how to show each of these terms are tensors. Do I need to expand out each covariant derivate to get a bunch of connection coefficients and then see some cancellations? Still though, I'm not too sure what I'll want to see after all of this so that I can say "…therefore $R$ is a tensor".  Also, very much related to the question, I'm a bit confused with the difference between  $\nabla_Y Z$ $\space \space $ and $\space \space $  $\nabla_{\mu}\omega$.  The second one I know as the covariant derivative of a 1-form, but what is meant by the covariant derivate of a vector $\textit{field}$? As in, what's the difference between the $\nabla_Y$ and $\nabla_{\mu}$?  Edit: In answering this last question, I have realised that $\nabla_YZ=Y^{\mu}\nabla_{\mu}Z^{\nu}$ and $\nabla_{\mu}\omega=\nabla_{\mu}\omega_{\nu}$. What is the limit of this sequence? How does it relate to the exponential function? Find $$\lim_{n\to\infty} \left(1+\frac{x^2}{n^2}\right)^n$$   I particular, I am hoping to find the above to be $1+x^kg(x/n)$ where $g(\cdot)$ is a function with uniformly bounded derivatives.  Edit: I'm trying to prove a result that would be true if  $(1+x^2/n^2)^n -1 = x^kO(x/n).$ Are planets actually moving in elliptical orbits around the Sun or do they move in circular orbits around their center of mass? In every derivation of Kepler's Laws that I have seen, we assume that the sun is stationary. However, in other places I have read that celestial bodies move about their barycentre (center of mass). So are planets actually moving in elliptical orbits around the Sun or do they move in circular orbits around their center of mass? I am having problems booting my Ubuntu after an attempted hardware fix today. My laptop was working fine but had some minor issues, so we tried a different motherboard, which had a major issue, so we changed it back to the original board. However, now I have problem booting.  The title pretty much says it all. I am using Ubuntu 16.04, but on boot, I get:  [    0:000000] [Firmware Bug]: TSC_DEADLINE disabled due to Errata; please update microcode to version: 0x52 (or later)   and I am now stuck at the BusyBox (initramfs).  Does anyone know how to fix this issue? I am not so familiar with bash or initramfs, so I would appreciate a detailed step-to-step guide if possible. Can't update because the word prox* is blocked When, if ever, should voting override answer acceptance for answer sorting? The accepted answer always appears at the top of the list, regardless of sort order. This can be misleading if the question author accepted an invalid solution and a better solution was proposed later, and eventually got more votes. I have seen somewhat obscure questions where the accepted answer has a negative score and the next answer has 10 or more up-votes. Gravity as a gauge theory Currently, (classical) gravity (General Relativity) is NOT a gauge theory (at least in the sense of a Yang-Mills theory).   Why should "classical" gravity be some (non-trivial or "special" or extended) gauge theory? Should quantum gravity be a gauge theory?  Remark: There are some contradictory claims in the literature to this issue. To what extent gravity is "a gauge" theory?Obviously, GR is not a YM theory. So, why do some people say that gravity "IS" a gauge theory? I found this question relevant, e.g., then we handle GR in the Einstein-Cartan theory or any other theory beyond GR, like teleparallel theories or higher-derivative gravitational theories. So I think it could be useful to discuss the "gauge flavor" of gravity here. Evaluate the integral $\int_0^\infty \frac{dx}{\sqrt{(x^3+a^3)(x^3+b^3)}}$ I really hope someone will take a quick look at the following, I would just love to better understand it...  This exercise is from Arnold's "Mathematical Methods of Classical Mechanics", p. 97 in the chapter on d'Alemberts principle:  A rod of weight P, tilted at an angle of 60° to the plane of a table, begins to fall with initial velocity zero. Find the constraint force of the table at the initial moment, considering the table as  (a) absolutely smooth  (b) absolutely rough  (In the first case, the holonomic constraint holds the end of the rod on the plane of the table, and in the second case, at a given point.)"      I must admit, I am pretty unsure on how to do calculations using this "fancy" mathematical kind of physics.  First off, I'm lost with (a). But I'll have a go at (b): As far as I understood, d'Alemberts principle states, that if $M$ is a constraining manifold, $x(q)$ is a curve in $M$ and $\xi$ is a vector perpendicular to $T_xM$, then $x$ satisfies Lagrange's equations  $\frac{d}{dt} \frac{\partial L}{\partial \dot q} = \frac{\partial L}{\partial q} \qquad L = \frac{{\dot x}^2}{2} - U(x)$  iff for the following inner product, we have  $\left(m \ddot x + \frac{\partial U}{\partial x}, \xi \right) = 0$  I guess that's about right so far? The constraint would in this case essentially be $\mathbb S^1$, since the rod moves on a circe around the point in contact with the table. Can we assume that all the rod's mass is at the center of mass?  Would we then have $U(x) = -gx_2$ in this case (where $x_2$ is the vertical component of $x$)?  If yes, then $\partial U / \partial x = -ge_2$. Where $e_1, e_2$ are the horizontal and vertical unit vectors, respectively.  At the inital moment, we have $x = \cos(60°) e_1 + \sin(60°) e_2$, so by d'Alembert's principle we must have  $\left(m \ddot x + \frac{\partial U}{\partial x}, \cos(60°) e_1 + \sin(60°) e_2 \right) = 0$  or written differently  $m \ddot {x_1} \cos(60°) + m \ddot{x_2} \sin(60°) - \sin(60°)g = 0$    So: Is this correct so far? Or am I way off? Is (a) handled any differently up to this point?  Thanks for reading (and hopefully thanks for your helpful reply)!  If anyone could recommend a good problem book (with solutions), in which this kind of mathematical approach is used (I don't know if this is how physicists would actually compute stuff??), I would greatly appreciate it.  Kind regards,  Sam How to discard unsaved changes to a view when editing it leads to a WSOD? If the laws of random variables weakly converge to a point mass at $c$, then the random variables converge in probability to $c$. This is question 10.3.1 from Rosenthal's First Look at Rigorous Probability.  Suppose $\mathcal{L}(X_n) \Rightarrow \delta_c$ for some $c \in \mathbb{R}$. Prove that $\{X_n\}$ converges to $c$ in probability.  Here $\mathcal{L}(X_n)$ refers to the distribution of $X_n$.  Is the following proof correct?  Is a simpler proof available?  Is there a simple proof using Skorohod's theorem?  I attempted to prove the contrapositive. Suppose $X_n \not \to c$ in probability.  This means that there is an $\varepsilon &gt; 0$ so that for all $N$, there exists an $m &gt; N$ such that  \begin{equation}   P(|X_m - c| \geq \varepsilon) &gt; \eta, \text{ for some $\eta &gt; 0$}. \end{equation}  Consider  \begin{equation}   B := \{x \in \mathbb{R} : |x - c| \leq \varepsilon\} \in \mathcal{B} \text{ the Borel sets on $\mathbb{R}$}. \end{equation}  Then $B^c \in \mathcal{B}$ and denoting the distribution of $X_n$ as $\mu_n$ we have  \begin{equation}   \mu_n(B^c) = P(X_n \in B^c) = P(|X_n - c| \geq \varepsilon) &gt; \eta. \end{equation}  For all $N$, there exists an $m &gt; N$ such that the cumulative distribution function of $X_m$ is not the same as the cumulative distribution function of $\delta_c$; in particular it's mass changes somewhere at least $\varepsilon$ distance from $c$. Finally because $\delta_c(\{x\}) = 0$ for all $x \neq c$ this completes the proof. REST API composite query: How do I use the result of a query subrequest in the referenceId of another subrequest? I am using Salesforce's REST API to (1) retrieve a list of object IDs according to a query, then (2) retrieve the records that correlate to those IDs.  I am familiar with the Salesforce composite documentation .    My request looks like this:  POST: /services/data/v48.0/composite  {     "allOrNone":false,     "compositeRequest": [ {         "method":"GET",         "url": "/services/data/v48.0/query?q=SELECT+Id+FROM+My_Entity+WHERE+(CreatedById+!=+'asdfghjkl')",         "referenceId": "myEntity"         },{         "method":"GET",         "url": "/services/data/v48.0/composite/sobjects/My_Entity?ids=@{myEntity.records[0].Id}",         "referenceId":"myObject"     }] }   My response:  {     "compositeResponse" : [ {         "body" : {             "totalSize" : 21,             "done" : true,             "records" : [ {                 "attributes" : {                     "type" : "My_Entity",                     "url" : "/services/data/v48.0/sobjects/My_Entity/a0D6g000xxxxxxx"                 },                 "Id" : "a0D6g000xxxxxxx"                 }, {*record2*}, {*etc*}             ]},             "httpHeaders" : { },             "httpStatusCode" : 200,             "referenceId" : "myEntity"         }, {         "body" : [ {         "errorCode" : "PROCESSING_HALTED",         "message" : "'myEntity.records' references an invalid Datatype. Only Strings and primitive data types are allowed to be referenced from previous operations."         } ],         "httpHeaders" : { },         "httpStatusCode" : 400,         "referenceId" : "myObject"     } ] }   The first subrequest (the query) executes without errors.  My problem is the second subrequest.  I understand from  that I can refer to the ID of a single item (e.g. myEntity.records[0].Id).  Question: How do I use all items from myEntity.records in the second subrequest?