Where can I get a list of all the Stack Exchange sites available?  I have seen the list in the footer of Meta, but I'm not sure if this is the complete list.
Where can I find a list of all the Stack Exchange sites?  I need to ask a question about cars (where my total knowledge is about zero) but I can't find a cars Stack Exchange site - tried guessing all the obvious (and pun based) names.  I assume the list of a dozen or so at the bottom of this page is only a subset? There must be a site on a topic as geeky as cars!  A list of future/beta sites would also be useful - I found a few on topics I'm interested in only after they had been up for a while.
I have a SQL query that I am trying to optimize:  DECLARE @Id UNIQUEIDENTIFIER = 'cec094e5-b312-4b13-997a-c91a8c662962'  SELECT    Id,   MIN(SomeTimestamp),   MAX(SomeInt) FROM dbo.MyTable WHERE Id = @Id   AND SomeBit = 1 GROUP BY Id   MyTable has two indexes:  CREATE NONCLUSTERED INDEX IX_MyTable_SomeTimestamp_Includes ON dbo.MyTable (SomeTimestamp ASC) INCLUDE(Id, SomeInt)  CREATE NONCLUSTERED INDEX IX_MyTable_Id_SomeBit_Includes ON dbo.MyTable (Id, SomeBit) INCLUDE (TotallyUnrelatedTimestamp)   When I execute the query exactly as written above, SQL Server scans the first index, resulting in 189,703 logical reads and a 2-3 second duration.   When I inline the @Id variable and execute the query again, SQL Server seeks the second index, resulting in only 104 logical reads and a 0.001 second duration (basically instant).  I need the variable, but I want SQL to use the good plan. As a temporary solution I put an index hint on the query, and the query is basically instant. However, I try to stay away from index hints when possible. I usually assume that if the query optimizer is unable to do its job, then there is something I can do (or stop doing) to help it without explicitly telling it what to do.  So, why does SQL Server come up with a better plan when I inline the variable? In Ruby on Rails, how do I format a date with the "th" suffix, as in, "Sun Oct 5th"? I want to display dates in the format: short day of week, short month, day of month without leading zero but including "th", "st", "nd", or "rd" suffix.  For example, the day this question was asked would display "Thu Oct 2nd".  I'm using Ruby 1.8.7, and  just doesn't seem to do this.  I'd prefer a standard library if one exists. Show that $n-m$ is a multiple of 9 when $n$ and $m$ have same digits Lufthansa connecting flight at Munich, only 45 minutes in between. Will I be able to make it? I bought a single ticket from Lufthansa, of Mumbai to Paris. My first flight (LH765) lands at 5:55am at Munich, from where I have another Lufthansa flight (LH2226) to Paris at 6:40am. This is a single ticket so I guess its responsibility of the airline to get me on the second flight, but since it's Non-Schengen to Schengen, will customs etc. be a problem? I am assuming the checked-in luggage would transferred automatically by the airline. Will I be able to make it? So I noticed that many cards with tap-effects ship with a clause specifying that they can only be used on untapped permanents, such as  and .  So here's my question:   Doesn't that imply that, given the right situation, one can legally tap an already tapped permanent?   I'll give an example of the kinda scenarios this is relevant for: Can  activate her first ability when no untapped cards are around? Or, thinking untap-effects, could I bounce a forest with  even when there isn't a tapped creature available?  Notice that, unlike the previous batch of examples, the wording on these lacks the clause restricting their use to un/tapped permanents - does that mean that they aren't?  Any kind of clarification would be greatly appreciated here. Replicate the Fourier transform time-frequency domains correspondence illustration using TikZ How to correctly add a path to PATH? how to hide mesh but keep hair particles Let $A$ be a commutative ring with $1$. Let $I$ and $J_k$, $k=1,\dots,n$ be ideals of $A$ with $I\subseteq \cup _{k=1}^n J_k$. Then I have obtained the following:  (1) If $J_k$, $k=1,\dots,n$, are prime ideals, then there exists some $j$ such that $I\subseteq J_j$.   (2) If $A$ is a principal ideal ring, then there exists some $j$ such that $I\subseteq J_j$.   I want some counterexamples that for all $k=1,\dots,n$, $I$ is not contained in $J_k$. How to get the counterexamples? $\newcommand{\P}{\mathbb{P}}$Is it valid to interpret $\P(B|A)$ as "infinite probability" when $\P(A) = 0$? Recurrence relation for number of ternary strings that contain two consecutive zeros The question is: Find a recurrence relation for number of ternary strings of length n that contain two consecutive zeros.    I know for ternary strings with length one, there are 0. For a length of 2, there is just 1 (00), and for a length of 3, there are 5 (000,001,002,100,200).    I did a similar problem, finding a relation for the number of bit strings of length n with two consecutive zeros: $$a_n = a_{n-1} + a_{n-2} + 2^{n-2}$$    Since you can add "1" to the end of all the $a_{n-1}$ strings, "10" to all the $a_{n-2}$ strings, and "00" any string of size $n-2$.    For the ternary string problem, I'm pretty sure you would replace the $2^{n-2}$ with $3^{n-2}$, but confused about the other terms of the relation. My guess is that it would have the coefficient $2$ in front of the other terms, since you can add either $1$ or $2$ to the end of $a_{n-1}$ and either $01$ or $02$ at the end of $a_{n-1}$.    So I believe the answer for the relation is: $$a_n = 2a_{n-1} + 2a_{n-2} + 3^{n-2}$$    How does that look? Truncate a string to first n characters of a string and add three dots if any characters are removed Product of elements of a finite abelian group Suppose $G=\{a_1,...,a_n\}$ is a finite abelian group, and let $x=a_1a_2\dotsm a_n$.   Prove that if there is more than one element of order $2$ then $x=e$.   What I've done so far: (#1 is just for illustration, There should be at least $3$ such elements)   $G$ has an even number of elements with order $&gt;2$ (They are paired so: $(a,a^{-1})$ ). And then there are $e$ and $\{b|o(b)=2\}$. Also, if $G$ has at least one element of order 2 then $|G|$ is even (Lagrange). Thus $|\{b|o(b)=2\}|$ must be odd. If there is exactly one element $b$ of order $2$ then $x=b$. That's because $G$ is abelian, and we can write: $x=e\cdot b\cdot(a_1 a_{1}^{-1}\dotsm a_n a_{n}^{-1})=b\cdot(e\dotsm e)=b$. If there are exactly $3$ such elements $a,b,c\in G$, then, as shown above, $x=abc$ and thus $x=e$ (That's because $(abc)^2=a^2b^2c^2=e$ which means $abc\in \{a,b,c,e\}$. If $abc=a$ then $b=c^{-1}=c$ which is false, same goes for $abc=b,abc=c$.)   I haven't managed to find a reason why the claim must hold for $5, 7, ...$ (i.e. All other odd integers). Does anyone have an idea?  Thanks in advance. Please excuse my English.  edit: Not a canonical answer but a simple one (if such even exists). Delete data using 2 DialogForm In how many different ways can we place $8$ identical rooks on a chess board so that no two of them attack each other? In how many different ways can we place $8$ identical rooks on a chess board so that no two of them attack each other?  I tried to draw diagrams onto a $8\times8$ square but I'm only getting $16$ ways.  Does that sound right?  Thanks for the help! How to decide whether missing values are MAR, MCAR, or MNAR I have a large proteomics dataset. In the rows I have the proteins , and in the rows I have the samples.The dataset contains a lot of missing values.  I would like to know I can find out whether missing values are MAR, MCAR, or MNAR, and how I can decide the best imputation technique. Kind regards. Determining if trees within forest gaps are clustered using R? The attached dataset shows approximately 6000 saplings in approximately 50 variable sized forest gaps.  I am interested in learning how these saplings are growing within their respective gaps (i.e. clustered, random, dispersed).  As you know, a traditional approach would be to run Global Moran's I.  However, aggregations of trees within aggregations of gaps seems to be an inappropriate use of Moran's I.  I ran some test statistics with Moran's I using a threshold distance of 50 meters, which produced nonsensical results (i.e. p-value = 0.0000000...).  The interaction among the gap aggregations are likely producing these results.  I have considered creating a script to loop through individual canopy gaps and determine the clustering within each gap, although displaying these results to the public would be problematic.    What is the best approach to quantify clustering within clusters? Highlight the difference between two strings in PHP What is the easiest way to highlight the difference between two strings in PHP?  I'm thinking along the lines of the Stack Overflow edit history page, where new text is in green and removed text is in red. If there are any pre-written functions or classes available, that would be ideal. Is it possible to dual boot two OS's at the same time? Is it possible to dual boot two OS's at the same time?  For example: I'm currently dual booting Ubuntu 11.04 and Windows 7. Ubuntu is running on a single 500gb HDD, Windows 7 is running on 1TB RAID 1 mirror. To switch between the two OS's, a reboot is required. Is it possible to switch between the two OS's without a reboot?  NOTE: I'm fully aware of the capabilities of VirtualBox and VMWare Player - I use both. Please don't answer "Use Virtualization!"  EDIT: If this is not possible can you share why it's not possible? To me, it doesn't seem like it would be that difficult. Keep in mind that my vision is unencumbered by knowledge! Triangular Numbers Modulo $k$ - Hit All Values?