I have a table duplicate which shows datas as:  select * from ot.duplicate;     I wanted to delete the duplicate data from the table where I tried:  delete  from (select * from(select * from ot.duplicate a union select * from ot.duplicate b) t1);   But I am getting error:  ORA-01752: cannot delete from view without exactly one key-preserved table
I'm testing something in Oracle and populated a table with some sample data, but in the process I accidentally loaded duplicate records, so now I can't create a primary key using some of the columns.  How can I delete all duplicate rows and leave only one of them?
What are the existing datasets of world maritime routes? Should we have a subjective version of every Stack Exchange site? Some icons are correct, and some are whack. Turns out it's not just the hot questions list, but the whole icon set. Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file I am performing an update and its failing on the following:  The repository 'http://ppa.launchpad.net/izx/askubuntu/ubuntu xenial Release' does not have a Release file..   Running a local Ubuntu server 16.04 CAML query daterange not working How to show that if $\phi(n)$ equals to n itself, then n must be 1? Easily measure elapsed time How can I merge properties of two JavaScript objects dynamically? Can I mix MySQL APIs in PHP? How are "Suggested Tags" chosen? After you've typed in a question, you get suggested tags that appear that look like this:        It appears that you need a minimum amount of characters ():     you must have entered a title (any length) and a minimum body length of 220 characters.   But other than that, how are the tags chosen? Is it:   A match of the title/body with other questions (taking the tags from those questions) A match of the title/body with tag excerpts (taking tags with overlap) A match of the title/body with tag wikis (taking tags with overlap) All of the Above None of the Above Other (please explain)   Some additional info from :  The suggested tags seem to only pop up on meta.so (they do not work on regular Stack Overflow, or on other SE sites).  While we're on the topic, why isn't this feature implemented network-wide? Bounding box is larger than expected when drawing a curved path I have been working on logo for my department and I have the following code. The problem is that whenever I compile the diagram seems to be larger than the actual logo. I do not know what is the problem. I know the numbers I have selected are not the best but any insights into the matter will be highly appreciated.   \documentclass[letterpaper]{article}  \usepackage[top=2cm,bottom=2cm,left=2cm,right=2cm]{geometry}  %\usepackage{amsmath,amssymb,units}  %\usepackage{enumitem,multicol}  \usepackage{tikz}  %\usetikzlibrary{arrows}  \usepackage{lipsum}   \begin{document}   \lipsum[1-2]  \begin{tikzpicture}[y=0.80pt, x=0.8pt,yscale=-1]  \path[draw=black,fill=white]    (258.9527,290.5199) .. controls (173.9885,538.4766) and (568.5860,261.2969) ..    (306.5098,257.1141) .. controls (44.4337,252.9312) and (429.9845,542.5624) ..    (352.9767,292.0206) .. controls (275.9689,41.4788) and (119.6549,497.6604) ..    (334.1376,346.9999) .. controls (548.6203,196.3394) and (66.4622,188.6439) ..    (276.0276,346.0724) .. controls (485.5930,503.5010) and (343.9169,42.5633) ..    (258.9527,290.5199) -- cycle;  \end{tikzpicture}  \lipsum[1-2]  \end{document}    See image below: Bluetooth audio delay / lag, reason completely unclear to me I have a bit of an odd situation, and wanted to ask for ideas.   Recently started connecting a JBL Charge 2+ to my MBA 11 inch, mid-2013, via Bluetooth. I noticed that there's clear delay between sound event and sound being audible via the JBL.   The problems persists across applications (so for example, playing video via VLC means the sound isn't synced, same for youtube videos in different browsers, same for mp3s that start playing with a small delay, etc.)  The delay is minor, but noticeable, in the range of 0.5s I'd say.  At first I thought it might be a Bluetooth driver issues, but now I found out the following: just connected another JBL device, a Flip 3 to the same MBA, and the sound plays without noticeable delay. I'm not sure if they use the exact same drivers, but now I'm wondering:   Is there a chance that it's a hardware problem? Didn't really consider this a possibility, but now I'm not sure anymore. How to test, and, ideally, fix this issue? How can I isolate the reason for the audio lag with the Charge 2+?   Any help would be appreciated! What is the current state of apple device (iPhone, iPod, etc.) support? What ubuntu applications provide support? (guides, how to's, status) Also, specifically, details on support for syncing music to iPhone's and iPod's with the latest OS version:   Can you sync music to apple devices using >iOS4? (iPhone &amp; iPod) What applications allow you to do this and how? (guides, how to's, status)    What has already been established is:   Apple does not support Linux and has no plans to.  provides some support, however it currently does not support music/video synchronization with devices &gt;iOS4. Go to  and scroll to the section titled "" to see if your device version is supported. Converting LAS 1.4 to 1.2 LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in programs and tools but unfortunately they were all trial versions of license pay versions.  Problem is that I can't open and generate DEMs of LAS version 1.4 in many open and free tools (such as MCC-Lidar).   Can you help me converting LAS from 1.4 to 1.2 in some free tool? Or if it is any other way for LAS 1.4. Is osmosis a kind of thermal machine? The hyperphysics article defines osmosis as a process driven by internal energy and internal energy is defined as energy associated with random,disordered motion of molecules. Osmosis develops pressure and lifts weight so it has the output of a machine.  But what drives osmosis? Is osmosis driven at the expense of thermal energy although there is no temperature gradient? Prevent VLC from starting a new instance every time a media file is opened How can I determine whether a conference is reputable? I recently received an invitation to a conference and I'm trying to determine how reputable it is. Is there a good way to go about this? There's a part in my apps that displays the file path loaded by the user through OpenFileDialog. It's taking up too much space to display the whole path, but I don't want to display only the filename as it might be ambiguous. So I would prefer to show the file path relative to the assembly/exe directory.  For example, the assembly resides at C:\Program Files\Dummy Folder\MyProgram and the file at C:\Program Files\Dummy Folder\MyProgram\Data\datafile1.dat then I would like it to show .\Data\datafile1.dat. If the file is in C:\Program Files\Dummy Folder\datafile1.dat, then I would want ..\datafile1.dat. But if the file is at the root directory or 1 directory below root, then display the full path.   What solution would you recommend? Regex?  Basically I want to display useful file path info without taking too much screen space.  EDIT: Just to clarify a little bit more. The purpose of this solution is to help user or myself knowing which file did I loaded last and roughly from which directory was it from. I'm using a readonly textbox to display the path. Most of the time, the file path is much longer than the display space of the textbox. The path is supposed to be informative but not important enough as to take up more screen space.  Alex Brault comment was good, so is Jonathan Leffler. The Win32 function provided by DavidK only help with part of the problem, not the whole of it, but thanks anyway. As for James Newton-King solution, I'll give it a try later when I'm free. Edge won't connect to internet, Skype for business won't screen-share, Windows Store won't update apps after Windows 10 version 1809 installed Similar to '', is it also ok to add an example?   I was going to  but I noticed that one answer had most of the things I needed to say, except perhaps that the questioner didn't perhaps understand the answer and  I feel that an example may help.