Search Results

Search found 18191 results on 728 pages for 'single board'.

Page 214/728 | < Previous Page | 210 211 212 213 214 215 216 217 218 219 220 221  | Next Page >

• Grasp Controller, Does it really need a UI to exist?

  - by dbones

  I have a Domain model which can be in multiple states, and if these states go out of a given range it the domain should automatically react. For example I have a Car which is made of multiple things which have measurements the Engine - Rev counter and Temperature the Fuel Tank - capacity Is is plaseable to have a CarStateController, which observses the engine and the tank, and if these states go out of range IE the engine temperature goes above range, turn the engine fan on?? There is no UI, (you could argue it would show a light on the dash board, but for this case it does not) is this a valid use of a GRASP controller pattern? if not what is this CarStateController Called? Or have I completely missed the point and this should be the State Pattern?

  Read the article

• Removing HTML entities while preserving line breaks with JSoup

  - by shrodes

  I have been using JSoup to parse lyrics and it has been great until now, but have run into a problem. I can use Node.html() to return the full HTML of the desired node, which retains line breaks as such: Gl&oacute;andi augu, silfurn&aacute;tt <br />Bl&oacute;&eth; alv&ouml;ru, starir &aacute; <br />&Oacute;&eth;ur hundur er &iacute; v&iacute;gam&oacute;&eth;, &iacute; maga... m&eacute;r <br /> <br />Kolni&eth;ur gref, kvik sem dreg h&eacute;r <br />Kolni&eth;ur svart, hvergi bjart n&eacute; But has the unfortunate side-effect, as you can see, of retaining HTML entities and tags. However, if I use Node.text(), I can get a better looking result, free of tags and entities: Glóandi augu, silfurnátt Blóð alvöru, starir á Óður hundur er í vígamóð, í maga... mér Kolniður gref, kvik sem dreg hér Kolniður svart, Which has another unfortunate side-effect of removing the line breaks and compressing into a single line. Simply replacing <br /> from the node before calling Node.text() yields the same result, and it seems that that method is compressing the text onto a single line in the method itself, ignoring newlines. Is it possible to have the best of both worlds, and have tags and entities replaced correctly which preserving the line breaks, or is there another method or way of decoding entities and removing tags without having to replace them manually?

  Read the article

• Disadvantages of MySQL Row Locking

  - by Nyxynyx

  I am using row locking (transactions) in MySQL for creating a job queue. Engine used is InnoDB. SQL Query START TRANSACTION; SELECT * FROM mytable WHERE status IS NULL ORDER BY timestamp DESC LIMIT 1 FOR UPDATE; UPDATE mytable SET status = 1; COMMIT; According to this webpage, The problem with SELECT FOR UPDATE is that it usually creates a single synchronization point for all of the worker processes, and you see a lot of processes waiting for the locks to be released with COMMIT. Question: Does this mean that when the first query is executed, which takes some time to finish the transaction before, when the second similar query occurs before the first transaction is committed, it will have to wait for it to finish before the query is executed? If this is true, then I do not understand why the row locking of a single row (which I assume) will affect the next transaction query that would not require reading that locked row? Additionally, can this problem be solved (and still achieve the effect row locking does for a job queue) by doing a UPDATE instead of the transaction? UPDATE mytable SET status = 1 WHERE status IS NULL ORDER BY timestamp DESC LIMIT 1

  Read the article

• Possible to capture all events in a web browser?

  - by David

  I am working on a pet project and am at the research stage. Quick summary I am trying to intercept all form submits, onclick, and every single keydown. My library of choice is either jquery, or jquery + prototypejs. I figure I can batch up the events into a queue/stack and send it back to the server in time interval batches to keep performance relatively stable. Concerns Form submits and change's would be relatively simple.. Something like $("form :inputs").bind("change", function() { ... record event... }); But how to ensure I get precedence over the applications handlers as I have a habit of putting return false on a lot of my form handlers when there is a validation issue. As I understand it, that effectively stops the event in its tracks. My project For my smaller remote clients I will put their products onto a VPS or run it in my home data center. Currently I use a basic authentication system, given a username/password they see the website and then hopefully send me somewhat sane notes on what is broken or should be tweaked. As a better solution, I've written a simple proxy web server that does the above but allows me to have one DNS entry and then depending on credentials it makes an internal request relaying headers and re-writing URLS as needed. Every single html/text or application/* request is compressed and shoved into a sqlite table so I can partially replay what they've done. Now I am shifting to the frontend and would like to capture clicks, keydown's, and submits on everything on the page.

  Read the article

• Debugging kernel hang

  - by l.thee.a

  I am trying to run an app which is using a kernel mode driver. System locks up every hour and the only way to recover it is a hard reset. Sysrq stops responding, telnet sessions hang and there are no error messages of any kind. Unfortunately the board does not have ejtag support. I have been trying to isolate it functionally, but this is like looking for a needle in a hay stack. Any suggestions? PS: This is a mips linux system (2.6.31).

  Read the article

• how to implement enhanced session handling in PHP

  - by praksant

  Hi, i'm working with sessions in PHP, and i have different applications on single domain. Problem is, that cookies are domain specific, and so session ids are sent to any page on single domain. (i don't know if there is a way to make cookies work in different way). So Session variables are visible in every page on this domain. I'm trying to implement custom session manager to overcome this behavior, but i'm not sure if i'm thinking about it right. I want to completely avoid PHP session system, and make a global object, which would store session data and on the end of script save it to database. On first access i would generate unique session_id and create a cookie On the end of script save session data with session_id, timestamps for start of session and last access, and data from $_SERVER, such as REMOTE_ADDR, REMOTE_PORT, HTTP_USER_AGENT. On every access chceck database for session_id sent in cookie from client, check IP, Port and user agent (for security) and read data into session variable (if not expired). If session_id expired, delete from database. That session variable would be implemented as singleton (i know i would get tight coupling with this class, but i don't know about better solution). I'm trying to get following benefits: Session variables invisible in another scripts on the same server and same domain Custom management of session expiration Way to see open sessions (something like list of online users) i'm not sure if i'm overlooking any disadvantages of this solution. Is there any better way? Thank you!!

  Read the article

• Constructor Overloading

  - by Mark Baker

  Normally when I want to create a class constructor that accepts different types of parameters, I'll use a kludgy overloading principle of not defining any args in the constructor definition: e.g. for an ECEF coordinate class constructor, I want it to accept either $x, $y and $z arguments, or to accept a single array argument containg x, y and z values, or to accept a single LatLong object I'd create a constructor looking something like: function __construct() { // Identify if any arguments have been passed to the constructor if (func_num_args() > 0) { $args = func_get_args(); // Identify the overload constructor required, based on the datatype of the first argument $argType = gettype($args[0]); switch($argType) { case 'array' : // Array of Cartesian co-ordinate values $overloadConstructor = 'setCoordinatesFromArray'; break; case 'object' : // A LatLong object that needs converting to Cartesian co-ordinate values $overloadConstructor = 'setCoordinatesFromLatLong'; break; default : // Individual Cartesian co-ordinate values $overloadConstructor = 'setCoordinatesFromXYZ'; break; } // Call the appropriate overload constructor call_user_func_array(array($this,$overloadConstructor),$args); } } // function __construct() I'm looking at an alternative: to provide a straight constructor with $x, $y and $z as defined arguments, and to provide static methods of createECEFfromArray() and createECEFfromLatLong() that handle all the necessary extraction of x, y and z; then create a new ECEF object using the standard constructor, and return that Which option is cleaner from an OO purists perspective?

  Read the article

• Iterating Over <select> Using jQuery + Multi Select

  - by Kezzer

  This isn't quite as straight forward as one may think. I'm using a plugin called jQuery MultiSelect and multiple <select options using XSLT as follows: <xsl:for-each select="RootField"> <select id="{RootField}" multiple="multiple" size="3"> <option value=""></option> <xsl:for-each select="ChildField"> <option value="{ChildField}"><xsl:value-of select="ChildField"/></option> </xsl:for-each> </select> </xsl:for-each> The accompanying JavaScript is as follows: var selects = document.getElementsByTagName("select"); $.each(selects, function() { $(this).multiSelect(); }); This allows me to apply the multiSelect(); function to every single <select on the page. The behaviour is quite strange, every other <select is being changed into the dropdown list (all the even ones anyway). I can't see anything wrong in my JavaScript to cause this issue as it would iterate over every single one. To make it more clear, the only lists that have that JavaScript applied to it are ones in position 2, 4, 6 and 8 (out of the 9 which are on the page). Any ideas?

  Read the article

• Reading Unicode files line by line C++

  - by Roger Nelson

  What is the correct way to read Unicode files line by line in C++? I am trying to read a file saved as Unicode (LE) by Windows Notepad. Suppose the file contains simply the characters A and B on separate lines. In reading the file byte by byte, I see the following byte sequence (hex) : FE FF 41 00 0D 00 0A 00 42 00 0D 00 0A 00 So 2 byte BOM, 2 byte 'A', 2byte CR , 2byte LF, 2 byte 'B', 2 byte CR, 2 byte LF . I tried reading the text file using the following code: std::wifstream file("test.txt"); file.seekg(2); // skip BOM std::wstring A_line; std::wstring B_line; getline(file,A_line); // I get "A" getline(file,B_line); // I get "\0B" I get the same results using operator instead of getline file >> A_line; file >> B_line; It appears that the single byte CR character is is being consumed only as the single byte. or CR NULL LF is being consumed but not the high byte NULL. I would expect wifstream in text mode would read the 2byte CR and 2byte LF. What am I doing wrong? It does not seem right that one should have to read a text file byte by byte in binary mode just to parse the new lines.

  Read the article

• Checking if any of a list of values falls within a table of ranges

  - by Conspicuous Compiler

  I'm looking to check whether any of a list of integers fall in a list of ranges. The ranges are defined in a table defined something like: # Extra Type Field Default Null Key 0 int(11) rangeid 0 NO PRI 1 int(11) max 0 NO MUL 2 int(11) min 0 NO MUL Using MySQL 5.1 and Perl 5.10. I can check whether a single value, say 7, is in any of the ranges with a statement like SELECT 1 FROM range WHERE 7 BETWEEN min AND max If 7 is in any of those ranges, I get a single row back. If it isn't, no rows are returned. Now I have a list of, say, 50 of these values, not stored in a table at present. I assemble them using map: my $value_list = '(' . ( join ', ', map { int $_ } @values ) . ')' ; I want to see if any of the items in the list fall inside of any of the ranges, but am not particularly concerned with which number nor which range. I'd like to use a syntax such as: SELECT 1 FROM range WHERE (1, 2, 3, 4, 5, 6, 7, 42, 309, 10000) BETWEEN min AND max MySQL kindly chastises me for such syntax: Operand should contain 1 column(s) I pinged #mysql who were quite helpful. However, having already written this up by the time they responded and thinking it'd be helpful to fix the answer in a more permanent medium, I figured I'd post the question anyhow. Maybe SO will provide a different solution?

  Read the article

• How to make a increasing numbers after filenames in C?

  - by zaplec

  Hi, I have a little problem. I need to do some little operations on quite many files in one little program. So far I have decided to operate them in a single loop where I just change the number after the name. The files are all named TFxx.txt where xx is increasing number from 1 to 80. So how can I open them all in a single loop one after one? I have tried this: for(i=0; i<=80; i++) { char name[8] = "TF"+i+".txt"; FILE = open(name, r); /* Do something */ } As you can see the second line would be working in python but not in C. I have tried to do similiar running numbering with C to this program, but I haven't found out yet how to do that. The format doesn't need to be as it is on the second line, but I'd like to have some advice of how can I solve this problem. All I need to do is just be able to open many files and do same operations to them.

  Read the article

• BASH echo write mysql input

  - by jmituzas

  Have a bash menu where variables write to file for mysql input. heres what I have: echo "CREATE DATABASE '$mysqldbn'; #GRANT ALL PRIVILEGES ON *.* TO '$mysqlu'@'$myhost' IDENTIFIED BY '$mysqlup' WITH GRANT OPTION; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'$myhost' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'$myip' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES ON '$mysqldbn'.* TO '$mysqlu'@'localhost' IDENTIFIED BY '$mysqlup'; GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER, CREATE TEMPORARY TABLES< LOCK TABLES on '$mysqldbn'.* TO '$mysqlu'@'$rip' IDENTIFIED BY '$mysqlup';" > nmysql.db mysql -u root -p$mypass < nmysql.db problem is to get variables to show I had to put them in single quotes, the single quotes show up as I want for instances like '$mysqlu'@'localhost'. But how can I remove the quotes and still get to use the variable in the instance like, CREATE DATABASE '$mysqldbn' ? Double quotes wont work either, I am at a loss. Thanks in advance, Joe

  Read the article

• onclickView not working...runuithread solution????

  - by nivedita

  hi..i m new to android....i m stuck at a point would really appreciate if ne1 cn help pls.. i m developing an pp which has grid of colored rectangles..made changing the background of textView..dere are 3 buttons which cause the backgroundcolor to change according to some algo..n 2 textview which show the current sts f game now the problem is i hv button example (one f the three buttons) which chnges example.setOnClickListener (new Button.OnClickListener() {public void onClick(View v) { status_val.setText("true board-example working"); level_1_true(); } } ); level_1_true();-sets background color f rectangles dis above code results in "activity not responding"..ie onclick listner does not change the view. someone suggested me runonuithread..but i cnt get how n what to do.. how do i change the d view of screen by clicking the button???

  Read the article

• Model-binding an object from the repository by several keys

  - by Anton

  Suppose the following route: {region}/{storehouse}/{controller}/{action} These two parameters region and storehouse altogether identify a single entity - a Storehouse. Thus, a bunch of controllers are being called in the context of some storehouse. And I'd like to write actions like this: public ActionResult SomeAction(Storehouse storehouse, ...) Here I can read your thoughts: "Write custom model binder, man". I do. However, the question is How to avoid magic strings within custom model binder? Here is my current code: public class StorehouseModelBinder : IModelBinder { readonly IStorehouseRepository repository; public StorehouseModelBinder(IStorehouseRepository repository) { this.repository = repository; } public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) { var region = bindingContext.ValueProvider.GetValue("region").AttemptedValue; var storehouse = bindingContext.ValueProvider.GetValue("storehouse").AttemptedValue; return repository.GetByKey(region, storehouse); } } If there was a single key, bindingContext.ModelName could be used... Probably, there is another way to supply all the actions with a Storehouse object, i.e. declaring it as a property of the controller and populating it in the Controller.Initialize.

  Read the article

• Python BOM error in Ascii file

  - by Intosia

  I have a wierd annoying problem with Python 2.6 I trying to run this file (and the other), on my Embedded Linux ARM board. http://svn.tuxisalive.com/software_suite_v3/smart-core/smart-server/trunk/TDSService.py I get this error File "tuxhttpserver.py", line 1 SyntaxError: encoding problem: with BOM I know that error is about the BOM bytes etc etc. BUT, there are NO BOM bytes, its plain Ascii. I checked with a Hexeditor, and the linux File command says its Ascii. Im freaking out here... The code worked fine on my Sheevaplug (also a ARM based system).

  Read the article

• iPhone: How to Determine Average Light/Dark of an Area of an UIImage

  - by TechZen

  I need to place labels with a transparent background over a variable-content UIImage. Readability will vary significantly depending on the relationship between the color of the label's text and the color/luminosity of the area of the image displayed under the label. Since the image will be constantly changing, the color of the label's text needs to change in sync. I have found several techniques for determining the color, perceived luminosity etc of a single pixel. However, I need to rather quickly (while a view loads) determine the rough perceived color/luminosity of an area of the UIImage under the frame of the UILabel. I presume I will also need to measure the alpha because the same color/luminosity looks different at different alpha values. Is there a way to calculate such a value for an area? Will I be reduced to simply summing pixels? If it comes to that, is there an algorithm to accomplish this? I've thought of two possible approaches: Perform some "folding" operations i.e. combining pixels from one half of the area to the other half. Then repeat until I get a single value. Would this be practical? How would you logically combine pixels to average their perceived color/luminosity? Sample a statistically significant number of pixels in the area and then combine them (somehow) to get a rough measure. I think this problem comes up a lot these days with people being so found of customizing backgrounds. Seems like something that would be worth my time to bang out a category or class to handle this and then share it around.

  Read the article

• How should I organize complex SQL views in Rails?

  - by Benjamin Oakes

  I manage a research database with Ruby on Rails. The data that is entered is primarily used by scientists who prefer to have all the relevant information for a study in one single massive table for use in their statistics software of choice. I'm currently presenting it as CSV, as it's very straightforward to do and compatible with the tools people want to use. I've written many views (the SQL kind, not the Rails HTML/ERB kind) to make the output they expect a reality. Some of these views are quite large and have a fair amount of complexity behind them. I wrote them in SQL because there are many calculations and comparisons that are more easily done with SQL. They're currently loaded into the database straight from a file named views.sql. To get the requested data, I do a select * from my_view;. The views.sql file is getting quite large. Part of the problem is that we're still figuring out what the data we collect means, so there's a lot of changes being made to the views all the time -- and a ton of them are being created. Many of them need to be repeatable. I've recently run into issues organizing and testing these views. Rails works great for user interface stuff and business logic, but I'm not aware of much existing structure for handling the reporting we require. Some options I've thought of: Should I move them into the most relevant models somehow? Several of the views interact with each other, which makes this situation more complex than just doing a single find_by_sql, so I don't know if they should only be part of the model. Perhaps they should be treated as a "view" in the MVC sense? (That is, they could be moved into app/views/ and live alongside the HTML, perhaps as files named something like my_view.csv.sql which return CSV.) How would you deal with a complex reporting problem like this?

  Read the article

• drupal themes: .info file: how do I add more than 1 css file / js file to my theme?

  - by egarcia

  I'm creating a new Drupal theme. Until now, I only needed to include a single css file and a single js file. So my theme.info file had something like this: stylesheets[all][] = css/style.css scripts[] = js/script.js Now I must include jquery and jquery-ui in order to use a calendar date. These come with 2 new javascript files, and 1 additonal css file that I must add to the site. The calendar input form is going to be used in all pages (on a side block) so it is ok for me to load the extra css/javascript on all pages. I think the easiest thing would be to reference them on the .info file itself. At first I tried to just put them there with separate spaces: stylesheets[all][] = css/style.css css/ui-lightness/jquery-ui-1.8.1.custom.css scripts[] = js/jquery-1.4.2.min.js js/jquery-ui-1.8.1.custom.min.js js/reservations.js I emptied drupal's cache and... none of them loaded. I then tried separating each file with a comma, and flushing the cache again. Same result. I've browsed some drupal pages, but could not find how to add several javascript/css files on one theme (they always seem to add just 1 of each). So, how do I include several css/javascript files on the .info file?

  Read the article

• PowerPoint.Application not raising events in C#

  - by AdmSteck

  I have a simple application written in C# and .Net 2.0 that displays several PowerPoint 2003 files in a loop. (It is going to be used for a information board in our cafeteria) The application works fine on my development machine but when I deploy it to another machine the events I have registered for SlideShowNextSlide and PresentationClose are never fired. I have tried registering the events with this method. private void InitPPT() { app.SlideShowNextSlide += new Microsoft.Office.Interop.PowerPoint.EApplication_SlideShowNextSlideEventHandler(app_SlideShowNextSlide); app.PresentationClose += new Microsoft.Office.Interop.PowerPoint.EApplication_PresentationCloseEventHandler(app_PresentationClose); app.SlideShowEnd += new Microsoft.Office.Interop.PowerPoint.EApplication_SlideShowEndEventHandler(app_PresentationClose); } And with this method that I found here: private void InitPPT() { IConnectionPointContainer oConnPointContainer = (IConnectionPointContainer)app; Guid guid = typeof(Microsoft.Office.Interop.PowerPoint.EApplication).GUID; oConnPointContainer.FindConnectionPoint(ref guid, out m_oConnectionPoint); m_oConnectionPoint.Advise(this, out m_Cookie); } Do I need to register some dll's on the client machine or am I missing something.

  Read the article

• Advice needed: cold backup for SQL Server 2008 Express?

  - by Mikey Cee

  What are my options for achieving a cold backup server for SQL Server Express instance running a single database? I have an SQL Server 2008 Express instance in production that currently represents a single point of failure for my application. I have a second physical box sitting at the installation that is currently doing nothing. I want to somehow replicate my database in near real time (a little bit of data loss is acceptable) to the second box. The database is very small and resources are utilized very lightly. In the case that the production server dies, I would manually reconfigure my application to point to the backup server instead. Although Express doesn't support log shipping, I am thinking that I could manually script a poor man's version of it, where I use batch files to take the logs and copy them across the network and apply them to the second server at 5 minute intervals. Does anyone have any advice on whether this is technically achievable, or if there is a better way to do what I am trying to do? Note that I want to avoid having to pay for the full version of SQL Server and configure mirroring as I think it is an overkill for this application. I understand that other DB platforms may present suitable options (eg. a MySQL Cluster), but for the purposes of this discussion, let's assume we have to stick to SQL Server.

  Read the article

• JDBC call not executing

  - by dbyrne

  I am working on one of the DAOs for a medium sized web application. Unfortunately, it contains very convoluted logic, and makes hundreds of JDBC stored proc calls in loops. This is out of my control. I am working on a method inside the DAO which makes a single JDBC call. The simplified version of what this method looks like is this: DriverManager.registerDriver(new com.sybase.jdbc2.jdbc.SybDriver()); Connection con = DriverManager.getConnection((String)connectionDetails.get("DATABASE_URL") (String)connectionDetails.get("USERID"), (String)connectionDetails.get("PASSWORD")); String sqlToExecute = "{call " + STORED_PROC + "(?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)}"; CallableStatement stmt = con.prepareCall(sqlToExecute); //Maybe I should try calling clearParameters here? stmt.setString(1,someData); //....Set of parameters.... if (!stmt.execute()) { //execute method never returns false } stmt.close(); Its pretty much a textbook JDBC call. All this stored proc does is insert a single row. Here is where things get crazy: This code works when you run it through a debugger line by line, but fails when you run it "full speed". Not only does it fail, but it doesn't throw any exception! The execute method always returns true. It just breezes right through the JDBC call without inserting a row to the database. If you go through the log files, copy the stored proc call and run it manually, it works (just like it does in debug mode). Whats strange is that the rest of the DAO, with all its hundreds of looped stored proc calls, works fine. My thinking is that Connection or CallableStatement is caching some value behind the scenes that is screwing things up. Has anyone ever seen anything like this before? A JDBC call failing with no exceptions? I know it will be impossible to provide a complete solution to this without seeing the whole application, I am just looking for suggestions on possible issues to investigate.

  Read the article

• How can I perform this query between related tables without using UNION?

  - by jeremy

  Suppose I have two separate tables that I watch to query. Both of these tables has a relation with a third table. How can I query both tables with a single, non UNION based query? I want the result of the search to rank the results by comparing a field on each table. Here's a theoretical example. I have a User table. That User can have both CDs and books. I want to find all of that user's books and CDs with a single query matching a string ("awesome" in this example). A UNION based query might look like this: SELECT "book" AS model, name, ranking FROM book WHERE name LIKE 'Awesome%' UNION SELECT "cd" AS model, name, ranking FROM cd WHERE name LIKE 'Awesome%' ORDER BY ranking DESC How can I perform a query like this without the UNION? If I do a simple left join from User to Books and CDs, we end up with a total number of results equal to the number of matching cds timse the number of matching books. Is there a GROUP BY or some other way of writing the query to fix this?

  Read the article

• Moving and resizing JPanels object inside JFrame.

  - by Gabriel A. Zorrilla

  Continuing my quest of learning Java by doing a simple game, i stumbled upon a little issue. My gameboard extends JPanel as well as each piece of the board. Now, this presents some problems: Cant set size of each piece, therefore, each piece JPanel ocupy the whole JFrame, concealing the rest of the pieces and the background (gameboard). Cant set the position of the pieces. I have the default flow manager. Tried setbounds and no luck. Perhaps i should make the piece to extend other JComponent?

  Read the article

• A GUID as the MySQL table's Primary Key or as a separate column

  - by Ben

  I have a multi-process program that performs, in a 2 hour period, 5-10 million inserts to a 34GB table within a single Master/Slave MySQL setup (plus an equal number of reads in that period). The table in question has only 5 fields and 3 (single field) indexes. The primary key is auto-incrementing. I am far from a DBA, but the database appears to be crippled during this two hour period. So, I have a couple of general questions. 1) How much bang will I get out of batching these writes into units of 10? Currently, I am writing each insert serially because, after writing, I immediately need to know, in my program, the resulting primary key of each insert. The PK is the only unique field presently and approximating the order of insertion with something like a Datetime field or a multi-column value is not acceptable. If I perform a bulk insert, I won't know these IDs, which is a problem. So, I've been thinking about turning the auto-increment primary key into a GUID and enforcing uniqueness. I've also been kicking around the idea of creating a new column just for the purposes of the GUID. I don't really see the what that achieves though, that the PK approach doesn't already offer. As far as I can tell, the big downside to making the PK a randomly generated number is that the index would take a long time to update on each insert (since insertion order would not be sequential). Is that an acceptable approach for a table that is taking this number of writes? Thanks, Ben

  Read the article

• Solution: Android INSTALL_FAILED_INSUFFICIENT_STORAGE error.

  - by Andrew Smith

  The INSTALL_FAILED_INSUFFICIENT_STORAGE error is the bane of every Android developer's life. It happens regardless of app size, or how much storage is available. Rebooting the target device fixes the problem briefly, but it soon comes back. There are hundreds (if not thousands) of message board posts from people asking why the problem occurs, but the folks at Google are frustratingly silent on the issue. There is a simple workaround. If your test device is running Android 2.2 or later then add the android:installLocation attribute to your application's manifest file, with the value "preferExternal". This will force the app to be installed on the device's external storage, such as a phone's SD card. For example: <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.andrewsmith.android.darkness" android:installLocation="preferExternal" This is more of a band-aid than a fix, and it may not be ideal if you want your finished app to install on the device's internal memory. But it will at least make the development process a lot less frustrating.

  Read the article

< Previous Page | 210 211 212 213 214 215 216 217 218 219 220 221  | Next Page >