I have the join condition as below    Select ct.payment,pm.order    from contract as ct   left join payment_order as pm   on ct.con_id=pm.id     Here the table payment_order is in another database 'payment'. How can i query this using dblink. please help.
I'm going to guess that the answer is "no" based on the below error message (and ), but is there anyway to perform a cross-database query using PostgreSQL?  databaseA=# select * from databaseB.public.someTableName; ERROR:  cross-database references are not implemented:  "databaseB.public.someTableName"   I'm working with some data that is partitioned across two databases although data is really shared between the two (userid columns in one database come from the users table in the other database). I have no idea why these are two separate databases instead of schema, but c'est la vie...
I make homemade cayenne pepper sauce every year. I do add some liquid pectin to slightly thicken it so it will stick to food rather than roll off. After a month or so on the shelf it seems to separate a bit. What can I add to this so that it won't or is there a method I can do to stop this. We are slowly working our way into marketing this product down the line and this won't work for that reason. We are using a water bath canning method, vinegar based, no sugar added. Auto-inserting Stack Overflow affiliate into all Amazon links We have officially discontinued the Amazon book affiliate remnant ads, since despite our best efforts they don't perform well for our audience and cannot be made to perform well.  We've often wondered,   I'm thinking this isn't a problem; it has gotten lots of support historically. So we're going to go ahead and do it, so the company Amazon account is still getting some use, and we benefit a little.   To be clear: from this point on, all Amazon links posted on all sites will automatically be rewritten to add our affiliate link. We have a clever affiliate redirect that geolocates the IP address and redirects to the appropriate regional Amazon store (amazon.uk, amazon.ca, et cetera).  If you have any feedback on this, or suggestions, as they say &hellip; speak now or forever hold your peace! In case of shell-builtins (eg type itself):  $ type type type is a shell builtin  $ which type &lt;Doesn't return anything since it's a shell builtin, silently exits&gt;   In case of commands (normally) (eg python):  $ type python python is /usr/bin/python  $ which python /usr/bin/python   In case of which (which is a command located at /usr/bin/which)  $ type which which is hashed (/usr/bin/which) $ which which /usr/bin/which   Why does type which say that which is hashed? What is the significance of which being hashed and what does it actually mean? let's say that I have a following file structure:  ~/DIR1 -fileA -DIR2 --fileB   Then, being in ~, I run this script:  cp DIR1 NEWDIR2   And just an error happens:  cp: omitting directory ‘DIR1’   I understand why nothing from DIR1 gets copied (because I didn't use -r switch that would enforce recursion) but I'd expect the DIR1 folder itself copied to NEWDIR2 (so practically a creation of a new "NEWDIR2" in ~ or a creation of ~/NEWDIR2/DIR1).  Could someone explain to me why is my expectation wrong? Formal basis for variable substitution in limits So we do a lot of variable substitution in limits at school. Stuff like $\lim\limits_{x\to5}\ (x+1)^2\ =\ \lim\limits_{y\to6}\ y^2$, where we define the substitution $y = x + 1$.  But I've never been clear on what exactly the theoretical basis for this is. What is the formula that you're actually applying when you do variable substitution? What are the formal conditions under which it is possible?  My conjecture would be the following:  For all continuous $f$, and all real $a$: $\lim\limits_{x\to a}\ (f\circ g)(x)\ =\lim\limits_{x\to g(a)}\ f(x)$, where $g$ is a continuous function  So to take my first example, $f$ would be $x^2$, $g$ would be $x + 1$, and $a$ would be $5$.  Am I in the right area? If this is correct, can it be proven using $\epsilon$-$\delta$? I had a half-hearted shot at it the other night and didn't get anywhere. Selecting points within polygon and updating attributes using ArcPy? I have two feature classes, a polygon of sales areas for a city, and point layer of addresses. I want to select the addresses based on the sales area they are in and update their attribute table to show the sales area. I have searched python+point+in+polygon for other posts and I know how to select the polygons but I can't figure out how to populate the address points.   I found the following script that works but takes almost two hours to run.  import arcpy import os  # Allow overwrite  arcpy.env.overwriteOutput = True  # Script user input parameters polygonLayer = arcpy.GetParameter(0) pointLayer = arcpy.GetParameter(1) workspace = arcpy.GetParameter(2) copyField = = arcpy.GetParameterAsText (3)   # Add new field to target feature class  fieldList = arcpy.ListFields(pointLayer) fieldNameList = [] for field in fieldList:    fieldNameList.append(field.name) fieldType = arcpy.ListFields(polygonLayer,copyField)[0].type if not copyField in fieldNameList:     arcpy.AddField_management(pointLayer, copyField, fieldType)  arcpy.MakeFeatureLayer_management(polygonLayer, "PolygonLayer")  pntCursor = arcpy.UpdateCursor(pointLayer) for pnt in pntCursor:     rowID = pnt.OBJECTID     arcpy.MakeFeatureLayer_management(pointLayer, "PointLayer", '"OBJECTID" = ' + str(rowID))      # Polygon selection based on CONTAINS selection method     arcpy.SelectLayerByLocation_management("PolygonLayer", "CONTAINS", "PointLayer")      # Copy field values from polygon to point layer         polyCursor = arcpy.SearchCursor("PolygonLayer")             for poly in polyCursor:         pnt.setValue(copyField, poly.getValue(copyField))         pntCursor.updateRow(pnt)      arcpy.Delete_management("PointLayer")          del pntCursor, polyCursor, pnt, poly   I don't think I need to create a new field so I have simplified my script too:  # Import arcpy module import arcpy import os  # Allow overwrite  arcpy.env.overwriteOutput = True  # Script user input parameters polygonLayer = arcpy.GetParameter(0) pointLayer = arcpy.GetParameter(1) workspace = arcpy.GetParameter(2) fsaPoly = arcpy.GetParameterAsText (3) #FSA in FSA_Boundaries fsaPnt =  arcpy.GetParameterAsText (4) #FSA in Addresses   # Select all Address in FSA     polyCursor = arcpy.SearchCursor("PolygonLayer")      for poly in polyCursor: # Select based on CONTAINS      arcpy.SelectLayerByLocation_management(poly, "CONTAINS", "PointLayer")  # Add FSA to Address         pntCursor = arcpy.UpdateCursor("pointLayer")               for pnt in pointCursor:             pnt.setValue(fsaPnt, fsaPoly)             pntCursor.updateRow(pnt)   del pntCursor, polyCursor, pnt, poly   I know my update cursor is wrong but i'm stuck on how to update one feature class using information selected from the other.   I know I can do this manually but I need to do it for multiple cities so I would like to automate the process.   I am using Arc 10.2.2 to run my python script. Can I connect to SQL Server using Windows Authentication from Java EE webapp? I am currently investigating how to make a connection to a SQL Server database from my Java EE web application using Windows Authentication instead of SQL Server authentication. I am running this app off of Tomcat 6.0, and am utilizing the Microsoft JDBC driver. My connection properties file looks as follows:  dbDriver              = com.microsoft.sqlserver.jdbc.SQLServerDriver dbUser                = user dbPass                = password dbServer              = localhost:1433;databaseName=testDb dbUrl                 = jdbc:sqlserver://localhost:1433   I have zero problems with connecting to a SQL Server database in this fashion when using SQL Server authentication.  Is there any way I can retrieve the credentials of the user's Windows Authentication and use that authentication for SQL Server?  UPDATE: I know in ASP.net there is a way to set up Windows Authentication for access to the webapp, which is exactly what I am looking for, except I want to pass that token off to SQL Server for access to the database. I'm working through a problem regarding expected values in Markov chains, and at some point it says:     Recall from probability that if $X$ is a positive integer valued random variable, then $\mathbb{E}[X] = 1 + \sum^\infty_{k=1}\mathbb{P}(X &gt; k)$.   I know that by definition $\mathbb{E}[X] = \sum_a a\mathbb{P}(X = a)$, but I can't see how the above equality follows from this, nor am I sure if this is how to approach the problem. Is the W statistic output by wilcox.test() in R the same as the U statistic? I've recently been reading about the Mann-Whitney U test. It turns out that to carry out this test in R you actually need to run a Wilcoxon test!  My question: is the W statistic of wilcox.test in R identical to the U statistic? I have some data which looks like:  sampleA    ATGC    10   100 sampleA    ATGC    120  230 sampleA    ATGC    200  110   I want to print the min and max using the values in both column 3 and 4. So my output should look like:  sampleA   10  230   Thanks in advance YA dystopia novel of battle school with unusual military control scheme Labels and nesting gather and align I have nested gather and align according to  \begin{gather}        \sum\limits_{i=1}^n i + \text{expression} = \dfrac{n(n-1)}{2} \label{l1}\\        \begin{align}             a+\text{expression}&amp;=b \\ %\label{l2} doesnt work             c&amp;=d+\text{expression} \\             e+\text{long expression}&amp;=f-\text{expression}        \end{align}  \end{gather}   to get an output looking like this:   The problem is that it is not possible to label all equations separately. The problem is identical to that discussed in , except  that in my problem the first line needs to be centered.  Thanks for any help. I know people love to close duplicates so I am not asking for a reference to start learning statistics (as ).   I have a doctorate in mathematics but never learned statistics. What is the shortest route to the equivalent knowledge to a top notch BS statistics degree and how do I measure when I have achieved that.   If a list of books would suffice (assuming I do the exercises lets say), that's terrific. Yes, I expect working out problems to be an implicit part of learning it but I want to fast track as much as realistically possible. I am not looking for an insanely rigorous treatment unless that is part of what statistical majors generally learn. Calculate difference between two dates (number of days)? I've seen them maneuver. They definitely can go backwards. How fast can they go in reverse? Is warp speed possible, or is reverse limited to impulse power? If it is limited to impulse power, can they travel backwards under impulse power as fast as they travel forwards under impulse power? How can I install the Google Apps Package (Play Store, ...) on my Android device? Fast way to copy a large file on a LAN I am having some trouble with NFS, and I'd like to try using just plain old TCP.  I have no idea where to begin, though.  Hardware-wise, I am using an ethernet crossover cable to network two netbooks.  To network them, I type  $ sudo ifconfig eth0 192.168.1.1 up &amp;&amp; ping -c 10 -s 10 192.168.1.2 &amp;&amp; sudo /etc/init.d/nfs-kernel-server start   on the first netbook and  $ sudo ifconfig eth0 192.168.1.2 up $ ping -c 10 -s 10 192.168.1.1 $ mount /mnt/network1   on the second  where /mnt/network1 is specified in /etc/fstab as  192.168.1.1:/home /mnt/network1 nfs noauto,user,exec,soft,nfsvers=2 0 0  as well as in /etc/exports (using the syntax of that file), on the first netbook.  The above works fine, but the files and directories are huge. The files average about half a gigabyte a piece, and the directories are all between 15 and 50 gigabytes.   I'm using rsync to transfer them, and the command (on 192.168.1.2) is  $ rsync -avxS /mnt/network1 ~/somedir   I'm not sure if there's a way to tweak my NFS settings to handle huge files better, but I'd like to see if running an rsync daemon over plain old TCP works better than rsync over NFS.  So, to reiterate, how do I set up a similar network with TCP?  UPDATE:  So, after a good at few hours of attempting to pull myself out of the morass of my own ignorance (or, as I like to think of it, to pull myself up by my own bootstraps) I came up with some useful facts.  But first of all, what led me on this rabbit trail instead of simply accepting the current best answer was this: nc is an unbelievably cool program that resolutely fails to work for me. I've tried the netcat-openbsd and netcat-traditional packages with no luck whatsoever.  The error I get on the receiving machine (192.168.1.2) is:  me@netbook:~$ nc -q 1 -l -p 32934 | tar xv Can't grab 0.0.0.0:32934 with bind tar: This does not look like a tar archive tar: Exiting with failure status due to previous errors   route gives:  me@netbook:~$ route Kernel IP routing table Destination     Gateway         Genmask         Flags Metric Ref    Use Iface default         dir-615         0.0.0.0         UG    0      0        0 wlan0 link-local      *               255.255.0.0     U     1000   0        0 eth0 192.168.0.0     *               255.255.255.0   U     2      0        0 wlan0 192.168.1.0     *               255.255.255.0   U     0      0        0 eth0   But, here's the good news: having the static IP addresses set in /etc/network/interfaces, which I started doing while trying to get nc working, fixed all my NFS problems and rekindled my love for NFS.  The exact configuration I used (with 192.168.1.1 for the first netbook, of course) was:  auto eth0 iface eth0 inet static address 192.168.1.2 netmask 255.255.255.0   With those settings, the two netbooks will be able to ping each other directly after being booted up, without even an ifup.  Anyway, I'd still really like to see nc in action, so I'm hoping someone help me debug this process. Radial Schrodinger equation with inverse power law potential Recently I read a  about solving radial Schrodinger equation with inverse power law potential.  Consider the radial Schrodinger equation(simply set $\mu=\hbar=1$):  $$\left(-\frac{1}{2}\Delta+V(\mathbf{r})\right)\psi(\mathbf{r})=E\psi(\mathbf{r}).$$  A  gives a one-dimension equation:  $$-\frac{1}{2}D^2\phi(r)+\left(V(r)+\frac{1}{2}\frac{l(l+1)}{r^2}\right)\phi(r)=E\phi(r),$$  where $D=\dfrac{d}{dr}$, and $l$ is the azimuthal quantum number.  If we only consider the ground state, then $l=0$, so  $$-\frac{1}{2}D^2 \phi(r)+V(r)\phi(r)=E\phi(r).$$  We want to find eigenvalue $E$ such that $\phi(0)=\phi(+\infty)=0$.  The central potential discussed in the paper is of this form:  $$V(r)=\alpha r^{-\beta}.$$  It states (see page 4) that if $\beta&gt;2$ then the potential is repulsive (i.e. $\alpha&gt;0$).  My questions are:    Is this conclusion (i.e. If $\beta&gt;2$ then we must have $\alpha&gt;0$) generally valid in physics? What would happen if $\alpha&lt;0$ and $\beta&gt;2$? Is there 'ground state' in this condition? What about the condition $\alpha&gt;0$ and $\beta=1,2$? I have tried to solve the equation numerically with $\alpha=1,\beta=1,2$, and the ground state energy in this two conditions seem to be $0$, is my result correct?   P.S. When I try to find ground state when  $\alpha=-1,\beta=2$, the energy seem to be $-\infty$, which is qualitatively different from $\alpha=-1,\beta=1$. Why am I getting black photos when I use the Manual feature on my DSLR? I was taking photos a few days ago, and I had it set to Manual. After about four photos, the rest started coming out black. I could see through my eyepiece clearly, and it took the photo normally, but when I reviewed it they were all black. Can I have 2x2 workspaces in GNOME 3?