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  • SQL to insert latest version of a group of items

    - by Garett
    I’m trying to determine a good way to handle the scenario below. I have the following two database tables, along with sample data. Table1 contains distributions that are grouped per project. A project can have one or more distributions. A distribution can have one of more accounts. An account has a percentage allocated to it. The distributions can be modified by adding or removing account, as well as changing percentages. Table2 tracks distributions, assigning a version number to each distribution. I need to be able to copy new distributions from Table1 to Table2, but only under two conditions: 1. the entire distribution does not already exist 2. the distribution has been modified (accounts added/removed or percentages changed). Note: When copying a distribution from Table1 to Table2 I need to compare all accounts and percentages within the distribution to determine if it already exists. When inserting the new distribution then I need to increment the VersionID (max(VersionID) + 1). So, in the example provided the distribution (12345, 1) has been modified, adding account number 7, as well as changing percentages allocated. The entire distribution should be copied to the second table, incrementing the VersionID to 3 in the process. The database in question is SQL Server 2005. Table1 ------ ProjectID AccountDistributionID AccountID Percent 12345 1 1 25.0 12345 1 2 25.0 12345 1 7 50.0 56789 2 3 25.0 56789 2 4 25.0 56789 2 5 25.0 56789 2 6 25.0 Table2 ------ ID VersionID Project ID AccountDistributionID AccountID Percent 1 1 12345 1 1 50.0 2 1 12345 1 2 50.0 3 2 56789 2 3 25.0 4 2 56789 2 4 25.0 5 2 56789 2 5 25.0 6 2 56789 2 6 25.0

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  • MySql selecting default value if there are no result?

    - by Kenan
    i'm having 2 tables: members and comments. I select all members, and then join comments. But in comments I'm selecting some SUM of points, and if user never commented, I can't get that user in listing?! So how to select default value for SUM, or some other solution: SELECT c.comment_id AS item_id, m.member_id AS member_id, m.avatar, SUM(c.vote_value) AS vote_value, SUM(c.best) AS best, SUM(c.vote_value) + SUM(c.najbolji)*10 AS total FROM members m LEFT JOIN comments c ON m.member_id = c.author_id GROUP BY c.author_id ORDER BY m.member_id DESC LIMIT {$sql_start}, {$sql_pokazi}

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  • Java reduce CPU usage

    - by steve
    Greets- We gots a few nutters in work who enjoy using while(true) { //Code } in their code. As you can imagine this maxes out the CPU. Does anyone know ways to reduce the CPU utilization so that other people can use the server as well. The code itself is just constantly polling the internet for updates on sites. Therefore I'd imagine a little sleep method would greatly reduce the the CPU usage. Also all manipulation is being done in String objects (Java) anyone know how much StringBuilders would reduce the over head by? Thanks for any pointers

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  • How to avoid web server traffic peak resulting from iOS Newsstand app receiving a remote notification?

    - by thomers
    I'm developing an iOS Newsstand app. If it is suspended or not running and connected to a WLAN, Newsstand apps can be triggered by a Push remote notification to download the latest issue (in our case around 100MB) in the background. I'm using Urban Airship for the delivery of the Push broadcast. I'm now worrying about many many iOS devices hitting the web server for one big download more or less at the same time, because I expect the majority of the devices will receive the notification in a very short timeframe. Instead of broadcasts to all devices, should I rather send individual notifications to batches of small groups of devices, spreading them out over a longer period of time? And/or would a CDN like Amazon Cloudfront solve that issue easier/anyway?

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  • Can't fill a column of NULLs with actual values by making an association to the proper values in the

    - by UkraineTrain
    I have a table with separate columns for months, days and a varchar column for 6 hour increments for each day ('12AM', '6AM', '12PM', '6PM'). There's also a column that's supposed to have calculated numeric values for each of those 6 hour increments. These calculated values come from some reference table. This reference table contains values for each day for several months broken down by hour where each hour has its own column. So, basically, I have to add the values for each 6 hour increment. I have no idea how to associate the correct values in the reference table to those 6 hour increments. I will really appreciate any help on this.

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  • MySQL::Eliminating redundant elements from a table?

    - by Legend
    I have a table like this: +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | v1 | int(11) | YES | MUL | NULL | | | v2 | int(11) | YES | MUL | NULL | | +-------+---------+------+-----+---------+-------+ There is a tremendous amount of duplication in this table. For instance, elements like the following: +------+------+ | v1 | v2 | +------+------+ | 1 | 2 | | 1 | 3 | | 1 | 4 | | 1 | 5 | | 1 | 6 | | 1 | 7 | | 1 | 8 | | 1 | 9 | | 2 | 1 | | 4 | 1 | | 5 | 1 | | 6 | 1 | | 7 | 1 | | 8 | 1 | | 9 | 1 | +------+------+ The table is large with 1540000 entries. To remove the redundant entries (i.e. to get a table having only (1,9) and no (9,1) entries), I was thinking of doing it with a subquery but is there a better way of doing this?

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  • Time complexity of a powerset generating function

    - by Lirik
    I'm trying to figure out the time complexity of a function that I wrote (it generates a power set for a given string): public static HashSet<string> GeneratePowerSet(string input) { HashSet<string> powerSet = new HashSet<string>(); if (string.IsNullOrEmpty(input)) return powerSet; int powSetSize = (int)Math.Pow(2.0, (double)input.Length); // Start at 1 to skip the empty string case for (int i = 1; i < powSetSize; i++) { string str = Convert.ToString(i, 2); string pset = str; for (int k = str.Length; k < input.Length; k++) { pset = "0" + pset; } string set = string.Empty; for (int j = 0; j < pset.Length; j++) { if (pset[j] == '1') { set = string.Concat(set, input[j].ToString()); } } powerSet.Add(set); } return powerSet; } So my attempt is this: let the size of the input string be n in the outer for loop, must iterate 2^n times (because the set size is 2^n). in the inner for loop, we must iterate 2*n times (at worst). 1. So Big-O would be O((2^n)*n) (since we drop the constant 2)... is that correct? And n*(2^n) is worse than n^2. if n = 4 then (4*(2^4)) = 64 (4^2) = 16 if n = 100 then (10*(2^10)) = 10240 (10^2) = 100 2. Is there a faster way to generate a power set, or is this about optimal?

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  • Google maps and J-Query: Individual markers?

    - by user351189
    Hi there, I have created a Google maps mashup, where with a bit of input, I have managed to have a sidebar that links to a video icon/marker that then opens up an info window showing virtual tours. I would, however, like to put different coloured marker icons on the map depending on the category that the video is in. This would be easy enough to do, but my page is made up of a mixture of J-Query and JavaScript all calling to the individual flash files. Could someone help me with the code for adding extra marker icons for different categories? Here is the code: So, after the intial 'var camera;' point, there comes this: function addMarker(point, title, video, details) { var marker = new GMarker(point, {title: title, icon:camera}); GEvent.addListener(marker, "click", function() { if (details) { marker.openInfoWindowTabsHtml([new GInfoWindowTab("Video", video), new GInfoWindowTab("More", details)]); } else { marker.openInfoWindowHtml(video); } }); Then further down, is the code for calling the individual marker image. I would like to add another image to this list - would I start out by calling the new object 'camera-red.image' or something similar? function initialize() { if (GBrowserIsCompatible()) { map = new GMap2(document.getElementById("mapDiv")); map.setCenter(new GLatLng(51.52484592590448, -0.13345599174499512), 17); map.setUIToDefault(); var uclvtSatMapType = createUclVTSatMapType() map.addMapType(uclvtSatMapType); map.setMapType(uclvtSatMapType); camera = new GIcon(G_DEFAULT_ICON); camera.image = "ucl-video.png"; camera.iconSize = new GSize(32,37); camera.iconAnchor = new GPoint(16,35); camera.infoWindowAnchor = new GPoint(16,2); addMarkersToMap(); } The actual map can be found here: link text Thanks. Gray

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  • Browser timing out attempting to load images

    - by notJim
    I've got a page on a webapp that has about 13 images that are generated by my application, which is written in the Kohana PHP framework. The images are actually graphs. They are cached so they are only generated once, but the first time the user visits the page, and the images all have to be generated, about half of the images don't load in the browser. Once the page has been requested once and images are cached, they all load successfully. Doing some ad-hoc testing, if I load an individual image in the browser, it takes from 450-700 ms to load with an empty cache (I checked this using Google Chrome's resource tracking feature). For reference, it takes around 90-150 ms to load a cached image. Even if the image cache is empty, I have the data and some of the application's startup tasks cached, so that after the first request, none of that data needs to be fetched. My questions are: Why are the images failing to load? It seems like the browser just decides not to download the image after a certain point, rather than waiting for them all to finish loading. What can I do to get them to load the first time, with an empty cache? Obviously one option is to decrease the load times, and I could figure out how to do that by profiling the app, but are there other options? As I mentioned, the app is in the Kohana PHP framework, and it's running on Apache. As an aside, I've solved this problem for now by fetching the page as soon as the data is available (it comes from a batch process), so that the images are always cached by the time the user sees them. That feels like a kludgey solution to me, though, and I'm curious about what's actually going on.

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  • Any reason not to use USE_ETAGS with CommonMiddleware in Django?

    - by allyourcode
    The only reason I can think of is that calculating ETag's might be expensive. If pages change very quickly, the browser's cache is likely to be invalidated by the ETag. In that case, calculating the ETag would be a waste of time. On the other hand, a giving a 304 response when possible minimizes the amount of time spent in transmission. What are some good guidelines for when ETag's are likely to be a net winner when implemented with Django's CommonMiddleware?

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  • LINQ-like or SQL-like DSL for end-users to run queries to select (not modify) data?

    - by Mark Rushakoff
    For a utility I'm working on, the client would like to be able to generate graphic reports on the data that has been collected. I can already generate a couple canned graphs (using ZedGraph, which is a very nice library); however, the utility would be much more flexible if the graphs were more programmable or configurable by the end-user. TLDR version I want users to be able to use something like SQL to safely extract and select data from a List of objects that I provide and can describe. What free tools or libraries will help me accomplish this? Full version I've given thought to using IronPython, IronRuby, and LuaInterface, but frankly they're all a bit overpowered for what I want to do. My classes are fairly simple, along the lines of: class Person: string Name; int HeightInCm; DateTime BirthDate; Weight[] WeighIns; class Weight: int WeightInKg; DateTime Date; Person Owner; (exact classes have been changed to protect the innocent). To come up with the data for the graph, the user will choose whether it's a bar graph, scatter plot, etc., and then to actually obtain the data, I would like to obtain some kind of List from the user simply entering something SQL-ish along the lines of SELECT Name, AVG(WeighIns) FROM People SELECT WeightInKg, Owner.HeightInCm FROM Weights And as a bonus, it would be nice if you could actually do operations as well: SELECT WeightInKg, (Date - Owner.BirthDate) AS Age FROM Weights The DSL doesn't have to be compliant SQL in any way; it doesn't even have to resemble SQL, but I can't think of a more efficient descriptive language for the task. I'm fine filling in blanks; I don't expect a library to do everything for me. What I would expect to exist (but haven't been able to find in any way, shape, or form) is something like Fluent NHibernate (which I am already using in the project) where I can declare a mapping, something like var personRequest = Request<Person>(); personRequest.Item("Name", (p => p.Name)); personRequest.Item("HeightInCm", (p => p.HeightInCm)); personRequest.Item("HeightInInches", (p => p.HeightInCm * CM_TO_INCHES)); // ... var weightRequest = Request<Weight>(); weightRequest.Item("Owner", (w => w.Owner), personRequest); // Indicate a chain to personRequest // ... var people = Table<Person>("People", GetPeopleFromDatabase()); var weights = Table<Weight>("Weights", GetWeightsFromDatabase()); // ... TryRunQuery(userInputQuery); LINQ is so close to what I want to do, but AFAIK there's no way to sandbox it. I don't want to expose any unnecessary functionality to the end user; meaning I don't want the user to be able to send in and process: from p in people select (p => { System.IO.File.Delete("C:\\something\\important"); return p.Name }) So does anyone know of any free .NET libraries that allow something like what I've described above? Or is there some way to sandbox LINQ? cs-script is close too, but it doesn't seem to offer sandboxing yet either. I'd be hesitant to expose the NHibernate interface either, as the user should have a read-only view of the data at this point in the usage. I'm using C# 3.5, and pure .NET solutions would be preferred. The bottom line is that I'm really trying to avoid writing my own parser for a subset of SQL that would only apply to this single project.

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  • Can I optimize this at all?

    - by Moshe
    I'm working on an iOS app and I'm using the following code for one of my tables to return the number of rows in a particular section: return [[kSettings arrayForKey:@"views"] count]; Is there any other way to write that line of code so that it is more memory efficient? EDIT: kSettings = NSUserDefaults standardUserDefaults. Is there any way to rewrite my line of code so that whatever memory it occupies is released sooner than it is released now?

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  • Composite primary keys in N-M relation or not?

    - by BerggreenDK
    Lets say we have 3 tables (actually I have 2 at the moment, but this example might illustrate the thought better): [Person] ID: int, primary key Name: nvarchar(xx) [Group] ID: int, primary key Name: nvarchar(xx) [Role] ID: int, primary key Name: nvarchar(xx) [PersonGroupRole] Person_ID: int, PRIMARY COMPOSITE OR NOT? Group_ID: int, PRIMARY COMPOSITE OR NOT? Role_ID: int, PRIMARY COMPOSITE OR NOT? Should any of the 3 ID's in the relation PersonGroupRole be marked as PRIMARY key or should they all 3 be combined into one composite?? whats the real benefit of doing it or not? I can join anyways as far as I know, so Person JOIN PersonGroupRole JOIN Group gives me which persons are in which Groups etc. I will be using LINQ/C#/.NET on top of SQL-express and SQL-server, so if there is any reasons regarding language/SQL that might make the choice more clear, thats the platform I ask about. Looking forward to see what answers pops up, as I have thought of these primary keys/indexes many times when making combined ones.

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  • How can i test my DB speed? (Learning)

    - by acidzombie24
    I have design a database. Theres no columns with indexing, nor any code for optimizing. I am positive i should index certain columns since i search them a lot. My question is HOW do i test if any part of my database will be slow? ATM I am using sqlite and i will be switching to either MS Sql or MySql based on my host provider. Will creating 100,000 records in each table be enough? Or will that always be fast in sqlite and i need to do 1mil? Do i need 10mil before a database will become slow? Also how do i time it? I am using C# so should i use StopWatch or is there a ADO.NET/Sqlite function i should use?

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  • cakephp: how to make NOW() work in search condition ?

    - by kaklon
    I'm trying to get all records with date greater then now. I tried this but it doeasnt work: $all_dates = $this->TourDate->find('all', array('conditions' => array('TourDate.date >=' => 'NOW()'), 'order' => array('TourDate.date ASC'))); If I replace NOW() with the current date it works. Why's that?

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  • In Excel 2010, how can I show a count of occurrences on a specific date within multiple time ranges?

    - by Justin
    Here's what I'm trying to do. I have three columns of data. ID, Date(MM/DD/YY), Time(00:00). I need to create a chart or table that shows the number of occurrences on, say, 12/10/2010 between 00:00 and 00:59, 1:00 and 1:59, etc, for each hour of the day. I can do countif and get results for the date, but I cannot figure out how to show a summary of the count of occurrences per hour for the 24 hour period. I have months of data and many times each day. Example of data set is below. Any help is greatly ID Date Time 221 12/10/2010 00:01 223 12/10/2010 00:45 227 12/10/2010 01:13 334 12/11/2010 14:45 I would like the results to read: Date Time Count 12/10/2010 00:00AM - 00:59AM 2 12/10/2010 01:00AM - 01:59AM 1 12/10/2010 02:00AM - 02:59AM 0 ......(continues for every hour of the day) 12/11/2010 00:00AM - 00:59AM 0 ......... 12/11/2010 14:00PM - 14:59PM 1 And so on. Sorry for the length but I wanted to be clear. EDIT Here is a sample spreadsheet. Very little data, but I couldn't figure out a better way without having a huge file. Tested in notepad for formatting and worked ok on import as csv. PID,Date,Time 2888759,12/10/2010,0:10 2888760,12/10/2010,0:10 2888761,12/10/2010,0:10 2888762,12/10/2010,0:11 2889078,12/10/2010,15:45 2889079,12/10/2010,15:57 2889080,12/10/2010,15:57 2889081,12/10/2010,15:58 2889082,12/10/2010,16:10 2889083,12/10/2010,16:11 2889084,12/10/2010,16:11 2889085,12/10/2010,16:12 2889086,12/10/2010,16:12 2889087,12/10/2010,16:12 2889088,12/10/2010,16:13 2891529,12/14/2010,16:21

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  • Need help with an xpath query!

    - by gerrod
    Can anyone help with the following XPath question? Given the node-set: <table> <rows> <row> <value column="Product">Coal</value> <value column="Quantity">10000</value> </row> <row> <value column="Product">Iron</value> <value column="Quantity">5000</value> </row> <row> <value column="Product">Ore</value> <value column="Quantity">4000</value> </row> </rows> </table> I want to query to find the node sub-set with a given product name. Note that the product name is being supplied by an attribute of the current node being processed (i.e. "@name"). So when the @name attribute has the value of "Coal" I would expect this to be returned: <row> <value column="Product">Coal</value> <value column="Quantity">10000</value> </row> This is what I've come up with; I know it's wrong, because I don't get anything back. $table/rows/row[value[@column='Product'][text()=@name]] </code>

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  • finding out memory allocation hotspots in java

    - by Zamir
    Our GC is working hard and we have some pauses that we want to decrease. We have some memory allocation issues that we want to solve before or while we are tweaking with the actual JVM GC args. I would like to know which objects are making the GC sweat: is there a way to know which objects are evacuated every time the GC is working? is there a way to know which objects are moved between areas every time the GC is working? Is there a way to know which objects are in Eden area? I am working extensively with Jprofiler and Memory Analyzer. I would like to get this information on a running application in my staging environment.

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  • C++, using one byte to store two variables

    - by 2di
    Hi All I am working on representation of the chess board, and I am planning to store it in 32 bytes array, where each byte will be used to store two pieces. (That way only 4 bits are needed per piece) Doing it in that way, results in a overhead for accessing particular index of the board. Do you think that, this code can be optimised or completely different method of accessing indexes can be used? c++ char getPosition(unsigned char* c, int index){ //moving pointer c+=(index>>1); //odd number if (index & 1){ //taking right part return *c & 0xF; }else { //taking left part return *c>>4; } } void setValue(unsigned char* board, char value, int index){ //moving pointer board+=(index>>1); //odd number if (index & 1){ //replace right part //save left value only 4 bits *board = (*board & 0xF0) + value; }else { //replacing left part *board = (*board & 0xF) + (value<<4); } } int main() { char* c = (char*)malloc(32); for (int i = 0; i < 64 ; i++){ setValue((unsigned char*)c, i % 8,i); } for (int i = 0; i < 64 ; i++){ cout<<(int)getPosition((unsigned char*)c, i)<<" "; if (((i+1) % 8 == 0) && (i > 0)){ cout<<endl; } } return 0; } I am equally interested in your opinions regarding chess representations, and optimisation of the method above, as a stand alone problem. Thanks a lot

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  • MySQL 5 in MySQL 4 compatible mode for one database?

    - by Horace Ho
    In a recent project, I have to maintain some PHP code. I set up a development server and installed MySQL, Apache, PHP, ..etc. The program is terminated with an error: Unknown column _ _ _ in 'on clause' Cannot select .... Google shows that it's a change of syntax around JOINs, parentheses are needed. As you may imagine, fixing all that PHP SQL strings will be the last resort. _< Is is possible to config MySQL 5 to run at MySQL 4 compatible mode? Or even better, for only one database? Thanks! p.s. Since we are going to host the code on a new production server (MySQL 5 on a CentOS box), the chance to install MySQL 4 on the new server might be slim.

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  • Confused about technique to use to submit form

    - by user281180
    I have created a view in which i`m using clientsidevalidation. The jquery has a textbox , a table and a submit button. The table is empty at the beginning. Using jquery I populate the table with 2 columns ID and Name. I send the values to the controller using the submit button. My question are as follows: How do I send the values of the texbox and the table to the controller? Any guide please.

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  • Perl launched from Java takes forever

    - by Wade Williams
    I know this is an absolute shot in the dark, but we're absolutely perplexed. A perl (5.8.6) script run by Java (1.5) is taking more than an hour to complete. The same script, when run manually from the command line takes 12 minutes to complete. This is on a Linux host. Logging is the same in both cases and the script is run with the same parameters in both cases. The script does some complex stuff like Oracle DB access, some scp's, etc, but again, it does the exact same actions in both cases. We're stumped. Has anyone ever run into a similar situation? If not and if you were faced with the same situation, how would you consider debugging it?

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  • How to speed this kind of for-loop?

    - by wok
    I would like to compute the maximum of translated images along the direction of a given axis. I know about ordfilt2, however I would like to avoid using the Image Processing Toolbox. So here is the code I have so far: imInput = imread('tire.tif'); n = 10; imMax = imInput(:, n:end); for i = 1:(n-1) imMax = max(imMax, imInput(:, i:end-(n-i))); end Is it possible to avoid using a for-loop in order to speed the computation up, and, if so, how?

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