While using the "defrag /c" command in cmd, does Windows also defragment an ssd? Defrag /c will defragment all hardrive in the system, however I am not sure if it includes SSDs. Any help would be greatly appreciated!  thanks
Defragmenting an SSD drive is a bad idea and Windows 7 is (should be?) smart enough not to schedule defragmentation on such drives.  However, I've opened up Disk Defragmenter on my system and found, to my surprise, that my SSD has indeed been defragmented... recently!  Then I checked the disks selected for the scheduled defrag (I have one SSD and one normal disk), and there the list correctly shows only the non-SSD drive.   MSDN forum post seems to suggest that, at least on Windows 8, defragmenting an SSD drive will just cause the TRIM command to be sent to the drive, but there's no word on what actually happens if you try to defrag an SSD drive on Windows 7 (aside from the fact that it shouldn't happen automatically).  What happens in Windows 7 if one chooses to defrag and SSD? What could possibly have been the reason my SSD drive got been defragmented?  EDIT:  I just remembered - I've moved some folders (Users and ProgramData) from my SSD drive to my normal drive using junctions.  question suggests that this shouldn't have any effects at all on the defragmentation process, but could it have an effect on the "last run" in Disk Defragmenter?
What pressure should I run my Road Bike tyres at? There's a question for mountain bike tyres but I can't seem to find anything on here for road bikes. At the moment I'm running at around 90psi. Is that too much? too little?  Also, am I more likely to get punctures running at higher pressure?  I seem to be getting a lot lately. Upgrade SQL Server database Using Compatibility Level I've made a backup of a SQL Server database running on SQL Server 2008. I've restored that backup into a SQL Server 2012 instance. I've set the compatibility level on the restored instance to SQL Server 2012 (110).   What does this do to the database?   Does it, for example,    cause stored procedures to be examined for incompatibilities cause any updates to all of the data pages in the database Cause updates to to datapages as the are accessed in the future Cause errors in the future if stored procedures or views are executed that use incompatible syntax   Where in books on line, or else where, can I find more detail? How to show that when the linear transformation $\Phi =\psi \circ \phi : E \rightarrow G$ is injective, then $\phi$ is also injective? How to show that when the linear transformation $\Phi =\psi \circ \phi : E \rightarrow G$  (where $\phi : E \rightarrow F$ and $\psi : F \rightarrow G$) is (1) injective, then $\phi$ is injective and when (2) $\Phi$ is surjective, then $\psi$ is also surjective ?  I've tried to prove it by the definition of injection and surjection, but I'm not convinced myself by it.  For example, in the first case :  If $\Phi$ is injective, $\forall g \in G$, we have $0$ or $1$ $e \in E$ such as $\Phi(e)=g$.  $\Rightarrow \Phi(e) = \psi(\phi(e)) = \psi(f) =g$.   So $\forall f \in F$, we also have $0$ or $1$ $e \in E$ such as $\phi(e)=f \in F$.   $\Rightarrow \phi$ is injective.  Is this right or did I prove nothing at all ? I think it is easier to convince myself/ to understand with surjectivity but still.. Git ignore file for Xcode projects Which files should I include in .gitignore when using Git in conjunction with Xcode? Why should a CTE start with a semi-colon? I think the title says it all. I can't see any reason employers have to incentivize employees to contribute to their 401(k) evenly throughout the year. Instead couldn't they use a relatively simple formula that is based on how much of their income the employee has contributed to their 401(k) thus far for the year? If that or their current contribution is over the threshold, they get the match this pay period, even if they didn't contribute anything.  EDIT: To clarify, my employer matches 100% of the first 3% of my contribution and 50% of the next 2%. The match is added every pay period along with my contribution. I am pretty sure there is no "true-up" feature, so if I were to hit the $17.5K limit early, and not be able to contribute at least 5% of my salary, I would not get the full match. So I have to be careful to make my contributions evenly throughout the year to get the maximum match. Just trying to figure out my employer's motivation for requiring this. Isomorphism of factor groups I came across an intuitive statement on factor groups that I realized I did not know how to prove.   Let $G$ be a group, and let $H \unlhd G, K \unlhd G$ such that $H \cong K$. I want to show that $G/H \cong G/K$.   I'm not sure how exactly to construct such an isomorphism from an isomorphism $\varphi: H \to K$. Is that the correct approach? By extending such an isomorphism to an automorphism on $\varphi^{\uparrow}:G \to G$, then we could apply the First Isomorphism Theorem to the composition of the natural homomorphism $\mu: G \to G/K$ and that automorphism (for $\ker \mu\varphi^{\uparrow} = H$, if such a $\varphi^\uparrow$ exists).  Edit: Hamou points out this is false in the infinite case: can it still be salvaged in the finite case? Are there restrictions we can put on $G, H,$ and $K$ such that this is true? Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? I mean the density of air is $1.26 kg/m^3$, so with $100 km$ above us, it exerts much pressure on you when you walk outside. Why does the p-value double when using two-tailed test compared to one-tailed one? Since this has been marked as a duplicate, I want to clarify that it's not about critical values of one- vs two-tailed tests, but the calculation of the p-Value in this case.  I get that in a two-tailed test, you look at both sides of the distribution and therefore you split alpha in half and you need a more extreme test statistic to get a significant result (at the same alpha level).   In my understanding, the p-value is the probability to get this or a more extreme test statistics if the H0 is true. This is easily calculated for a one-tailed test: I just calculate the integral right of the empirical test statistic    For a normal distribution, a z-Value of 1.645 gives me a p-Value of ~0.05. But if I do the same procedure with a two-tailed test, SPSS/Excel doubles the p-value. I get that you now look on the other side of the distribution as well, and therefore I think it's the integral of z(test statistic) + z(-test statistic), but why? I did not get the result -1.645, so I don't understand why I should add the 2.5% of the other side. Colored item names in Minecraft? I came across a map and when I was playing I found some coloured and bolded item names. I thought it isn't possible as at most you can only use the custom name tag to rename things! Is there a way to colour and bold item names in vanilla Minecraft? External programs are OK. Oh, and the wiki page of formatting codes doesn't really do much. Is there a list of Ubuntu versions with default corresponding Linux kernel versions somewhere?  I would specifically like to know the most recent version of Ubuntu that still used Linux Kernel 2.x. I have an Android phone that connects with my computer via MTP. This works fine; I can see and transfer files with Nautilus. However, I often want to use the terminal to move large numbers of files, and I cannot seem to find the device anywhere in the filesystem tree. Nautilus reports the location as mtp://[usb:003,007]/, but it's not under /media or /mnt.  Does anyone know where it is? Windows 8.1 missing font files after restart Some days ago I rebooted my windows 8.1 system. After the reboot all my system texts were very cryptic - showing only some strange symbols. After some investigation I discovered that my c:\windows\fonts folder was nearly empty. So I copied the font files from another windows 8.1 installation to the nearly empty folder. As soon as I had copied the files the system texts were readable again.  But after another reboot the problem occured again - the systems font folder was empty again. Does anyone know why windows deletes my font files during a restart? I am posting this question just to get a better understanding of the questions that can be asked on Stack Overflow.  I find that  can several answers based on users opinion and cause a discussion.  Why is this a good question when several other requests for books and tutorials are not acceptable? Current Configuration: I have two SQL Servers, which are connected by the failover mechanism, meaning one is primary and one is secondary. I restarted both services on both servers sequentially. On the secondary server, all the databases are in the &quot;Synchronizing&quot; state. AG replication mode is synchronous. It has been 12hr it's still showing &quot;Synchronizing&quot; state. What I did so far to resolve Drop the database from the secondary server and remove the database from AG group on the primary server and add it back. Any insight on this, I am using SQL Server 2017. If I have bought 3 tickets for the same flight, can I bring three times the cabin allowance allowed per ticket?  The way I see it I am doing the airline a favor  Related: I have equations inside an environment which has a larger left-margin than the main text (analogous to an enumerate/itemize environment, implemented with the changepage package's adjustwidth environment). Just as equations in enumerate/itemize behave, the equations are centered with respect to the entire text, rather than just the width of the container environment. I want the latter behavior.  I'm trying to accomplish this by wrapping all display-math in minipages. Namely, I'm modifying the mathdisplay environment in amsmath.sty as follows:  \makeatletter \let\oldmd\mathdisplay \def\mathdisplay#1{%   \newline   \begin{minipage}{\textwidth-\@totalleftmargin}%     \oldmd{#1}% } \let\oldendmd\endmathdisplay \def\endmathdisplay#1{%   \oldendmd{#1}%   \end{minipage} } \makeatother   This is almost working, but there are some issues with spacing which I don't understand how to fix. Here's how the the normal \[ ... \] and numbered \begin{equation} ... \end{equation} look with the above modification:      My main confusion is why the numbered version is behaving so differently from the unnumbered. But all in all I want to fix this so that the spacing above and below is even as it usually is. Any help is appreciated, thanks.  Edit: Here's a compilable example:  \documentclass{amsart}  \usepackage{lipsum} \usepackage{calc} \usepackage{changepage}  \makeatletter \let\oldmd\mathdisplay \def\mathdisplay#1{%   \newline   \begin{minipage}{\textwidth-\@totalleftmargin}%     \oldmd{#1}% } \let\oldendmd\endmathdisplay \def\endmathdisplay#1{%   \oldendmd{#1}%   \end{minipage} } \makeatother  \setlength{\parindent}{0pt}  \begin{document}  \lipsum[1]  \begin{adjustwidth}{20pt}{} \lipsum[2] \[ x \mapsto \hom(-,x) \]  \lipsum[3] \begin{equation}   y \mapsto \hom(y,-) \end{equation} \lipsum[4] \end{adjustwidth}  \lipsum[5]  \end{document} Conky Widgets are Opening in their Own Windows I just upgraded to 16.04 and I'm getting all my customization set up again, but it seems that most Conky widgets are opening in their own window, instead of just appearing on the Desktop; although some are working correctly.  For example:  LSD (working properly):    Seamod (not working, opening in own window):    Since it's not affecting every single widget, I assume it could be an issue with the conkyrc with the widgets that aren't working, but this also never happened in 14.04 so I wasn't sure if maybe there was some compatibility issue in 16.04. My Google-fu has failed me in finding a solution.  If anyone can point me in the right direction, it would be much appreciated! :) Windows Server 2008 R2: User account set to not show on login This afternoon I set up a Win Server 2008 R2 system for use with Team Foundation source code control. In order to give my team-mates the right to connect, I had to create a user account for each person, 10 in total. (I can't, and I don't want to create a domain).  Now, after doing this, all user accounts are displayed in the login screen.  What can I do so that all the accounts are not displayed there? Shape of confidence interval for predicted values in linear regression I have noticed that the confidence interval for predicted values in an linear regression tends to be narrow around the mean of the predictor and fat around the minimum and maximum values of the predictor. This can be seen in plots of these 4 linear regressions:    I initially thought this was because most values of the predictors were concentrated around the mean of the predictor. However, I then noticed that the narrow middle of the confidence interval would occur even if many values of were concentrated around the extremes of the predictor, as in the bottom left linear regression, which lots of values of the predictor are concentrated around the minimum of the predictor.  is anyone able to explain why confidence intervals for the predicted values in an linear regression tend to be narrow in the middle and fat at the extremes?