Search Results

Search found 22961 results on 919 pages for 'memory management'.

Page 730/919 | < Previous Page | 726 727 728 729 730 731 732 733 734 735 736 737  | Next Page >

  • Inheriting database connection in PHP OOP

    - by vrode
    My abstract class Database is made for database interaction and any child of this class (UserDatabase, ActionDatabase, EventDatabase) inherits its database connection which is defined as static. `abstract class Database { static $connection = mysql_connect( ); } class UserDatabase extends Database { ... public function __construct( ) { $connection ? "connected" : "not connected"; $this-table = "users"; mysql_query( "FROM " . $this-table . " SELECT *" ); } } ` Does that mean, that my database connection is only set up and stored in memory once and passed on to subclasses as reference without being replicated for each instance? Is this how you would implement you OOP-correct database interface?

    Read the article

  • small string optimization for vector?

    - by BuschnicK
    I know several (all?) STL implementations implement a "small string" optimization where instead of storing the usual 3 pointers for begin, end and capacity a string will store the actual character data in the memory used for the pointers if sizeof(characters) <= sizeof(pointers). I am in a situation where I have lots of small vectors with an element size <= sizeof(pointer). I cannot use fixed size arrays, since the vectors need to be able to resize dynamically and may potentially grow quite large. However, the median (not mean) size of the vectors will only be 4-12 bytes. So a "small string" optimization adapted to vectors would be quite useful to me. Does such a thing exist? I'm thinking about rolling my own by simply brute force converting a vector to a string, i.e. providing a vector interface to a string. Good idea?

    Read the article

  • From xcode not able to execute DISTINCT keyword for sqlite

    - by mac
    -(void) readProductsFromDatabase { // Setup the database object sqlite3 *database; // Init the animals Array products = [[NSMutableArray alloc] init]; // Open the database from the users filessytem if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { NSLog(@"db opened"); // Setup the SQL Statement and compile it for faster access const char *sqlStatement = "SELECT DISTINCT productname FROM iphone "; sqlite3_stmt *compiledStatement; if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { // Loop through the results and add them to the feeds array while(sqlite3_step(compiledStatement) == SQLITE_ROW) { NSLog(@"inside sqlite3 prepare"); // Read the data from the result row NSString *aName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)]; } } // Release the compiled statement from memory sqlite3_finalize(compiledStatement); } sqlite3_close(database); } My problem is const char *sqlStatement = "SELECT DISTINCT productname FROM iphone "; This line not executing ,i am using sqlite3, thanks in advance,

    Read the article

  • Bitmap.Save problems

    - by user284026
    Hello, can anyone tell me if you know to be a problem with Bitmap and steganography for WM 6? I am working on a project and i have to hide a digital signature in a bitmap. The algorithm works perfect, as in untill i have the image on the memory the bitmap contains the modified bytes. But after i save the image (Bitmap.Save()) and I reopen the image, than those bytes are lost. When i say lost i mean they are the orriginal bytes from when the picture was taken. Thank you.

    Read the article

  • Multiple user database design

    - by dieguitoweb
    I have to develop a basic social network for an academic purpose; but I need some tips for the users management.. The users are subdivided into 3 groups with different privilege: admins,analysts and standards users. For every user should be stored into the database the following information: name,lastname,e-mail,age,password. I'm not quite sure how I should design the database between theese two solutions: 1)one table called 'users' with the 'role' attribute that explain what a user can do and what can't do, and the permissions are managed via php 2)every application user is a database user created with the query 'CREATE ROLE' (It's a postgres database) and he has permissions on some tables granted with the 'GRANT' statement You should take into account that the project is for a database exam.. thanks

    Read the article

  • reading specific lines from a file

    - by MacUsers
    What's the best way of reading only the specific lines (based on matching text) from a file? This is what I'm doing now: match_txt = "lhcb" for inFile in os.listdir('.'): readFile = open(inFile, 'r') lines = readFile.readlines() readFile.close() for line in lines: if line.find(match_txt)==0: #< do stuff here > i.e. I'm reading the lines, only with "lhcb" in it, from all the files in the present directory one by one. Is it the best way of doing that? Can it be done without loading the whole file in the memory in the first place?

    Read the article

  • Is it a good idea to define a variable in a local block for a case of a switch statement?

    - by Paperflyer
    I have a rather long switch-case statement. Some of the cases are really short and trivial. A few are longer and need some variables that are never used anywhere else, like this: switch (action) { case kSimpleAction: // Do something simple break; case kComplexAction: { int specialVariable = 5; // Do something complex with specialVariable } break; } The alternative would be to declare that variable before going into the switch like this: int specialVariable = 5; switch (action) { case kSimpleAction: // Do something simple break; case kComplexAction: // Do something complex with specialVariable break; } This can get rather confusing since it is not clear to which case the variable belongs and it uses some unnecessary memory. However, I have never seen this usage anywhere else. Do you think it is a good idea to declare variables locally in a block for a single case?

    Read the article

  • Is a full list returned first and then filtered when using linq to sql to filter data from a databas

    - by RJ
    This is probably a very simple question that I am working through in an MVC project. Here's an example of what I am talking about. I have an rdml file linked to a database with a table called Users that has 500,000 rows. But I only want to find the Users who were entered on 5/7/2010. So let's say I do this in my UserRepository: from u in db.GetUsers() where u.CreatedDate = "5/7/2010" select u (doing this from memory so don't kill me if my syntax is a little off, it's the concept I am looking for) Does this statement first return all 500,000 rows and then filter it or does it only bring back the filtered list?

    Read the article

  • Performing regex on a stream

    - by takoi
    I have some large text files which im going to preform consecutive matching on (just capturing, not replacing). Im thinking its not such a good idea to keep the whole file in memory, but rather use a Reader. What i know about the input is that if there's a match, its not going to span more than 5 lines. So my idea was to have some sort of buffer which just keeps these 5 lines, or so, do the first search, and continue. But it has to "know" where the regex match ended for this to work. e.g if the match ends at line 2 it should start the next search from here. Is it possible to do something like this in an efficient way?

    Read the article

  • C++'s unordered_map / hash_map / Google's dense_hash - how to input binary data (buf+len) and insert

    - by shlomif
    Hi all, I have two questions about Google's dense_hash_map, which can be used instead of the more standard unordered_map or hash_map: How do I use an arbitrary binary data memory segment as a key: I want a buffer+length pair, which may still contain some NUL (\0) characters. I can see how I use a NUL-terminated char * string , but that's not what I want. How do I implement an operation where I look if a key exists, and if not - insert it and if it does return the pointer to the existing key and let me know what actually happened. I'd appreciate it if anyone can shed any light on this subject. Regards, -- Shlomi Fish

    Read the article

  • Is it a good practice to create a reference to application context and use it anywhere?

    - by kknight
    I have to use context in many places of my code such as database operations, preference operations, etc. I don't want to pass in context for every method. Is it a good practice to create a reference to application context at the main Activity and use it anywhere such as database operations? So, I don't need some many context in method parameters, and the code can avoid position memory leak due to use of Activity Context. public class MainActivity extends Activity { public static Context s_appContext; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); s_appContext = this.getApplicationContext();

    Read the article

  • Image gets slightly erased on SWT/Windows

    - by zvikico
    I have an Eclipse plugin which includes a view. The view has several icons in the toolbar. I'm experiencing a very strange problem: on Windows, in some occasions (after prolonged use), one of the icons gets slightly erased. This does not happen on other platforms. This looks like a memory leak or some other resource misuse, but I just can't figure out where. The rest of the icons, which are initialized and used in the exact same manner are not affected. I tried working with Sleak, but I really don't see anything out of the ordinary. Any help would be appreciated.

    Read the article

  • Shortest command to calculate the sum of a column of output on Unix?

    - by Andrew
    I'm sure there is a quick and easy way to calculate the sum of a column of values on Unix systems (using something like awk or xargs perhaps), but writing a shell script to parse the rows line by line is the only thing that comes to mind at the moment. For example, what's the simplest way to modify the command below to compute and display the total for the SEGSZ column (70300)? ipcs -mb | head -6 IPC status from /dev/kmem as of Mon Nov 17 08:58:17 2008 T ID KEY MODE OWNER GROUP SEGSZ Shared Memory: m 0 0x411c322e --rw-rw-rw- root root 348 m 1 0x4e0c0002 --rw-rw-rw- root root 61760 m 2 0x412013f5 --rw-rw-rw- root root 8192

    Read the article

  • delete & new in c++

    - by singh
    Hi This may be very simple question,But please help me. i wanted to know what exactly happens when i call new & delete , For example in below code char * ptr=new char [10]; delete [] ptr; call to new returns me memory address. Does it allocate exact 10 bytes on heap, Where information about size is stored.When i call delete on same pointer,i see in debugger that there are a lot of byte get changed before and after the 10 Bytes. Is there any header for each new which contain information about number of byte allocated by new. Thanks a lot

    Read the article

  • how to restore very large .bak file (180 GB) in SQL Server 2008

    - by Umutos
    Hello! I have a verly large .bak file (180 GB) which was stored in Microsoft SQL Server 2008 and I have to restore it. I first installed Microsoft SQL Server 2008 Express and tried to restore it in MS SQL management studio express but it didn't work because there is a size limit. Does anybody know a method how i can restore the file? Its the first time I work with Microsoft SQL and I have no clue what to do. Its really urgend and I would be really helpful for any help! Thanks a lot! Umutos

    Read the article

  • UITableView with contact image problems.

    - by prathumca
    As par my app requirement, I'm showing the contact images in a UITableView as shown below. ABRecordRef contact = [self getContact]; if(contact && ABPersonHasImageData(contact)) { UIImage *contactImage = [UIImage imageWithData:(NSData*)ABPersonCopyImageData(contact)]; callImage.image = contactImage; } I've two problems if I use the above code segment. Table Scrolling is too slow. If comment the above code, then UITable responds very fast. Memory Management. My app started using 25 - 30 MB of RAM. Is there any better way to avoid the above two problems?

    Read the article

  • What is the correct way of handling a reloaded view after it was dismissed?

    - by favo
    Hi, I have the same problem as the guy here: http://stackoverflow.com/questions/2682844/uiimagepickercontroller-reloads-view-after-its-dismissed I have a UIView with a UIDatePicker within a Popover. When the Popover is dismissed and presented again, it sometimes resets the Picker in the view because hidden views are unloaded when a memory warning occurs. This is the part displaying the view: endCompareDateTimePicker.picker.maximumDate = [NSDate dateWithTimeIntervalSinceNow:0]; [endCompareDateTimePopover presentPopoverFromRect:sender.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES]; The picker (IBOutlet UIDatePicker) does not stay initiated. Adding a [endCompareDateTimePicker loadView] helped out and got me the picker initiated to set the correct date values before displaying the view. While this is working, I dont think this is the proper way doing this. What would be the correct way to handle this situation?

    Read the article

  • Maven/Ivy: Identical artifact with different name in dependency

    - by ThiamTeck
    Currently I am using Ivy for dependency management. And quite often I come across problem of getting identical jar files with different name due to transitive dependency. Example: <dependency> <groupId>javax.mail</groupId> <artifactId>mail</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>org.apache.geronimo.specs</groupId> <artifactId>geronimo-javamail_1.4_spec</artifactId> <version>1.4</version> </dependency> I am thinking of trying out Maven as well. Any best practice to eliminate these identical artifact in either Ivy or Maven?

    Read the article

  • Problems opening large csv file

    - by John Tyler
    I have a csv file that is 100mb in size. I need to parse some data out of it into a new format. I tried PHP, but keep running into memory issues. After around the first 150 "rows" or so, the script poops out. This is even on the localhost, and doing everything I can to tune the PHP settings, including max_memory and script_execution_time. Now before I continue, I'd like to know if Python will poop out on me too. Or if I will have to use C++. Can someone name good csv libraries for for these programmin langueage? The file is quoted csv. I mean scheiza I can't even open this text file in OpenOffice without it dying on me. (then again, Java sux as bad as PHP)

    Read the article

  • Calculation of derived field in sql

    - by Matt
    Taking Sql this quarter and not having any luck with the following question: The height of players in feet (inches/12). Include their name. Hint: Calculation or derived field. Be sure to give the calculated field a column header. We're learning the basic Select statment and didn't find any reference on how to make custom data at w3schools. I'm using Microsoft SQL server Management Express Here's my statment so far: select nameLast, nameFirst, height from Master where height (I assume its something like 'Player_Height' = height/12) order by nameLast, nameFirst, height Thanks for the help

    Read the article

  • SQL Server 2008: The columns in table do not match an existing primary key or unique constraint

    - by 109221793
    Hi guys, I need to make some changes to a SQL Server 2008 database. This requires the creation of a new table, and inserting a foreign key in the new table that references the Primary key of an already existing table. So I want to set up a relationship between my new tblTwo, which references the primary key of tblOne. However when I tried to do this (through SQL Server Management Studio) I got the following error: The columns in table 'tblOne' do not match an existing primary key or UNIQUE constraint I'm not really sure what this means, and I was wondering if there was any way around it?

    Read the article

  • Is there any conflict between NFS and calling getFD().sync()?

    - by Dr.Dredel
    My boss is worried that our NFS file system will not be happy with the jboss run java process calling getFD().sync on the files we are writing. We have noticed that frequently the time stamp on the created file is minutes (sometimes as many as 15 minutes) after the log claims the file was finished writing. My only guess is that the NFS is hanging on to the file in memory and not writing it till it feels like it. sync should solve that probelm, right? I also noticed that there is never a close() called on the file. Wondering if that could have been the cause as well? any thoughts appreciated.

    Read the article

  • Question regrarding declaring a property

    - by Simon
    Hi. We declare properties using the @property keyword and synthesize it in the implementation file. My question is, What if I declare a property using the @property keyword and also declare a variable in the interface block with the same name? For example, consider the following code, Interface: @interface myClass : NSObject { NSString *myClass_name; // LINE 1 } @property(nonatomic, retain) NSString *myClass_name; // LINE 2 @end Implementation: @implementation myClass @synthesize myClass_name @end Declaring myClass_name in LINE 1 will make any problem? Like any reference problem or any unnecessary memory consumption problem?

    Read the article

  • Byte order (endian) of int in NSLog?

    - by Eonil
    NSLog function accepts printf format specifiers. My question is about %x specifier. Does this print hex codes as sequence on memory? Or does it have it's own printing sequence style? unsigned int a = 0x000000FF; NSLog(@"%x", a); Results of above code on little or big endian processors are equal or different? And how about NSString's -initWithFormat method? Does it follows this rule equally?

    Read the article

  • Is file_get_contents multi line?

    - by Abs
    Hello all, Does file_get_contents maintain line breaks? I thought it did but I have tried this: if($conn){ $tsql = file_get_contents('scripts/CreateTables/SLR05_MATCH_CREATETABLES.sql'); $row = sqlsrv_query($conn, $tsql); print_r(sqlsrv_errors()); } The errors I get is that SQL Server complains that there is incorrect syntax. I get the same errors when I run the SQL Script without any line breaks, which suggests file_get_contents removes them? When I run the script normally (open the file in SQL Server Management Studio) and execute it, it works perfectly. So is there something that I can use that maintains line breaks etc? Or is there another problem here in using queries from a file with the SQL Server PHP Driver from Microsoft? Thanks all for any help

    Read the article

< Previous Page | 726 727 728 729 730 731 732 733 734 735 736 737  | Next Page >