Why is this query not using indexing?
MySQL not using indexes with WHERE IN clause?
why don't we define vector multiplication component-wise? I was just wondering why we don't ever define multiplication of vectors as individual component multiplication.  That is, why doesn't anybody ever define $\langle a_1,b_1 \rangle \cdot \langle a_2,b_2 \rangle$ to be $\langle a_1a_2, b_1b_2 \rangle$?  Is the resulting vector just not geometrically interesting? How to resolve merge conflicts in Git repository? How do Prestige Classes that advance spellcasting interact with racial spellcasting ability? For example Lets use the Marrutact from Sandstorm, it can cast as a 5th level wizard. if it then takes a prestige class that requires the ability to cast 1st level Arcane spells and advances arcane casting such as Abjurant Champion. assuming it meets all other prerequisites does the Marrutacts spellcasting improve when it takes a level in Abjurant Champion or does it gain no benefit? What do you do in Dungeon World when someone wants to perform an action they don't have a move for? So in Dungeon World, everything breaks down to 'moves'.  What about situations where a move is not available, but a check of some sort is called for, such as in the case of a non-fighter who wants to kick down the door?  What mechanism do you use to resolve that situation? Is there the equivalent of a skill check? Sorry, I'm still a newbie to blender, but why are some edges visible only in edit mode, but not in wireframe view? is it a bug or am I missing something here?  edit mode: Edges visible. Object mode, wireframe view: Pooff, they're gone. what can i do to fix this? / thanks How can I use Netflix on Ubuntu? After using the simple LM317 on breadboard variable power supply for a while, a need for a more rugged and reliable bench power supply has arose.    Short on money, i decided to build it as many other amateurs like me did. The thing is that, for my current needs i don't need a giant digitally controlled multi-channel 500 watt beast or something like that.  Instead what i really want is a low wattage positive and negative low voltage ouput -12v-0v-12v for example. However i really like that my power supply to be safe, reliable and fool-proof as far as possible. So after searching the web here and there, i found many designs that from my point of view fell in one of two divisions:-   Ones that use discrete op-amps and transistors. And ones that use integrated voltage regulators.   So -at least for me- i think that the ones with discrete op-amps and transistors are more prone to malfunctions and issues compared to the integrated ones with all of their internal over current and thermal protection circuits which would need to be discretely implemented in the bench power supplies that utilize discrete op-amps, however those designs have the advantage of ease of customization and more importantly that it is easier to have 0V output compared to 1.2V in integrated voltage regulator ones.    So i like advice to help me choose between circuits that utilize discrete op-amps like this circuit for example:-  Or ones that use integrated voltage regulators with their intrinsic robustness and low form factor.    Also as a side but related question i have seen many designs on the web that utilize negative voltage fed to the adjust or like pins to achieve 0V output from integrated voltage regulators like this single positive power supply:-     Or a positive and negative channels power supply that i really like its design because of simplicity (not because of laziness but to avoid the drawbacks that may come with complex designs especially when implemented by an amateur like me):- And the question is      Is it wrong or a system safety and reliability lowering act to feed negative voltage to adjust pin for LM317 for example?     I ask this question because the datasheet clearly states that the working output range is 1.2V-37V for LM317 for example, also no similar circuit is mentioned in the Typical Applications section except for the following one:- And even in that circuit, however the adjust pin is tied to the negative rail, it does't regulate during this interval instead it is shut until the next half wave at least that what i understand.    So at last to sum it up which alternative is best suited for my needs, its pros and cons and suggested circuits if possible. Meta's tag pages inaccessible due to self-redirect loop Moderncv adding date of birth to personal information Why the shape (sB) is unknown in the following code ? How to avoid this ?  \documentclass[]{standalone} \usepackage{tikz,xparse} \usetikzlibrary{calc}  \tikzset{pics/.cd,     % Marque croix     Cross/.style args={#1 and #2}{%         code = {%         \draw[#2,rotate=45,scale=1.4] (0,#1 pt) -- (0,-#1 pt) ;         \draw[#2,rotate=-45,scale=1.4] (0,#1 pt) -- (0,-#1 pt) ;         }     },     Cross/.default={2 and black} }  \NewDocumentCommand{\Segment}{mO{}}{%     \begin{scope}[#2]     \path    (0,0) coordinate (sA) pic {Cross={1.5 and gray}}         -- (#1,0) coordinate (sB) pic {Cross={1.5 and gray}} ;     \draw (sA)--(sB) ; % Can't reuse (sB)     \end{scope} }   \begin{document}     \begin{tikzpicture}     \Segment{1.5}     \end{tikzpicture} \end{document} I can't install Rainlendar 2 on my Ubuntu 18.04, I found this solution for 16.04 (), followed it, seems to work, but after install, there's no Rainlendar in my Show Apps, so I'm not sure what went wrong. When I issued sudo dpkg -i rainlendar2-pro_2.12.2.b138-1_amd64.deb, I got this:   Selecting previously unselected package rainlendar2-pro. (Reading database ... 190677 files and directories currently installed.) Preparing to unpack rainlendar2-pro_2.12.2.b138-1_amd64.deb ... Unpacking rainlendar2-pro (2.12.2.b138-1) ... dpkg: dependency problems prevent configuration of rainlendar2-pro:  rainlendar2-pro depends on libpng12-0; however:   Package libpng12-0 is not installed.  rainlendar2-pro depends on tofrodos; however:   Package tofrodos is not installed.  rainlendar2-pro depends on libjpeg62; however:   Package libjpeg62 is not installed.  rainlendar2-pro depends on libwebkitgtk-1.0-0; however:   Package libwebkitgtk-1.0-0 is not installed.  dpkg: error processing package rainlendar2-pro (--install):  dependency problems - leaving unconfigured Processing triggers for gnome-menus (3.13.3-11ubuntu1) ... Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.1) ... Processing triggers for mime-support (3.60ubuntu1) ... Errors were encountered while processing:  rainlendar2-pro   I got this after issuing this command in terminal sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages will be REMOVED:   rainlendar2-pro 0 upgraded, 0 newly installed, 1 to remove and 35 not upgraded. 1 not fully installed or removed. After this operation, 20.5 MB disk space will be freed. Do you want to continue? [Y/n] y (Reading database ... 191316 files and directories currently installed.) Removing rainlendar2-pro (2.12.2.b138-1) ... Processing triggers for mime-support (3.60ubuntu1) ... Processing triggers for desktop-file-utils (0.23-1ubuntu3.18.04.1) ... Processing triggers for gnome-menus (3.13.3-11ubuntu1) ...   What I'm doing wrong? After the last command it just removed Rainlendar and not installing dependencies as stated in the original post? TIA Browsing Quora, I saw the following  with contradicting answers.  For the :     The bits are represented by certain orientations of magnetic fields   which shouldn't have any effect on gravitational mass.   But,  contradicts that one:     Most importantly, higher information content correlates with a more   energetic configuration and this is true regardless of the particular   type of storage... Now, as per Einstein's most famous formula, energy   is equivalent to mass.   Which answer is correct? Can you have multiple Dropbox accounts on one computer? How can I prevent data theft from a company?  Are there any solutions to this problem?  Is there any software that encrypts important data (.doc, .xls, etc.) and prevents it from copying?  I need a solution where employees can read/write documents but can not copy then to a USB drive or e-mail them. How to make Gnome's "Activities" bar always visible? 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? Calculating the eigenvalues of a matrix Method defined as testMethod do not support web service callouts, test skipped Area is calculating wrong using $area in field calculator (QGIS 2.8.1-Wien) How do I send an HTTP request in C# without using System.Net classes?