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• De-normalization alternative to specific MYSQL problem?

  - by Booker

  I am facing quite a specific optimization problem. I currently have 4 normalized tables of data. Every second, possibly thousands of users will pull down up-to-date info from these tables using AJAX. The thing is that I can predict relatively easily which subset of data they need... The most recent 100 or so entries in those 4 normalized tables. I have been researching de-normalization... but feel that perhaps there is an easier solution. I was thinking that I could somehow every second run one sql query to condense the needed info, store it in a temp cached table and then have all of the user queries just draw from this. This will allow the complex join of 4 tables to only be run once, and then from there the users just need to do a simple lookup from the cached table. I really don't know if this is feasible. Comments on this or any other suggestions would be much appreciated. Thanks!

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• Hibernate: deletes not cascading for self-referencing entities

  - by jwaddell

  I have the following (simplified) Hibernate entities: @Entity @Table(name = "package") public abstract class Package { protected Content content; @ManyToOne(cascade = {javax.persistence.CascadeType.ALL}) @JoinColumn(name = "content_id") @Fetch(value = FetchMode.JOIN) public Content getContent() { return content; } public void setContent(Content content) { this.content = content; } } @Entity @Table(name = "content") public class Content { private Set<Content> subContents = new HashSet<Content>(); @ManyToMany(fetch = FetchType.EAGER) @JoinTable(name = "subcontents", joinColumns = {@JoinColumn(name = "content_id")}, inverseJoinColumns = {@JoinColumn(name = "elt")}) @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE, org.hibernate.annotations.CascadeType.REPLICATE}) @Fetch(value = FetchMode.SUBSELECT) public Set<Content> getSubContents() { return subContents; } public void setSubContents(Set<Content> subContents) { this.subContents = subContents; } } So a Package has a Content, and a Content is self-referencing in that it has many sub-Contents (which may contain sub-Contents of their own etc). The relationships are required to be ManyToOne (Package to Content) and ManyToMany (Content to sub-Contents) but for the case I am currently testing each sub-Content only relates to one Package or Content. The problem is that when I delete a Package and flush the session, I get a Hibernate error stating that I'm violating a foreign key constraint on table subcontents, with a particular content_id still referenced from table subcontents. I've tried specifically (recursively) deleting the Contents before deleting the Package but I get the same error. Is there a reason why this entity tree is not being deleted properly?

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• Does complex JOINs causes high coupling and maintenance problems ?

  - by ashkan.kh.nazary

  Our project has ~40 tables with complex relations.A colleague believes in using long join queries which enforces me to learn about tables outside of my module but I think I should not concern about tables not directly related to my module and use data access functions (written by those responsible for other modules) when I need data from them. Let me clarify: I am responsible for the ContactVendor module which enables the customers to contact the vendor and start a conversation about some specific product. Products module has it's own complex tables and relations with functions that encapsulate details (for example i18n, activation, product availability etc ...). Now I need to show the product title of some product related to some conversation between the vendor and customers. I may either write a long query that retrieves the product info along with conversation stuff in one shot (which enforces me to learn about Product tables) OR I may pass the relevant product_id to the get_product_info(int) function. First approach is obviously demanding and introduces many bad practices and things I normally consider fault in programming. The problem with the second approach seems to be the countless mini queries these access functions cause and performance loss is a concern when a loop tries to fetch product titles for 100 products using functions that each perform a separate query. So I'm stuck between "don't code to the implementation, code to interface" and performance. What is the right way of doing things ? UPDATE: I'm specially concerned about possible future modifications to those tables outside of my module. What if the Products module decided to change the way they are doing things? or for some reason modify the schema? It means some other modules would break or malfunction until the change is integrated to them. The usual ripple effect problem.

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• Python: How can I use Twisted as the transport for SUDS?

  - by jathanism

  I have a project that is based on Twisted used to communicate with network devices and I am adding support for a new vendor (Citrix NetScaler) whose API is SOAP. Unfortunately the support for SOAP in Twisted still relies on SOAPpy, which is badly out of date. In fact as of this question (I just checked), twisted.web.soap itself hasn't even been updated in 21 months! I would like to ask if anyone has any experience they would be willing to share with utilizing Twisted's superb asynchronous transport functionality with SUDS. It seems like plugging in a custom Twisted transport would be a natural fit in SUDS' Client.options.transport, I'm just having a hard time wrapping my head around it. I did come up with a way to call the SOAP method with SUDS asynchronously by utilizing twisted.internet.threads.deferToThread(), but this feels like a hack to me. Here is an example of what I've done, to give you an idea: # netscaler is a module I wrote using suds to interface with NetScaler SOAP # Source: http://bitbucket.org/jathanism/netscaler-api/src import netscaler import os import sys from twisted.internet import reactor, defer, threads # netscaler.API is the class that sets up the suds.client.Client object host = 'netscaler.local' username = password = 'nsroot' wsdl_url = 'file://' + os.path.join(os.getcwd(), 'NSUserAdmin.wsdl') api = netscaler.API(host, username=username, password=password, wsdl_url=wsdl_url) results = [] errors = [] def handleResult(result): print '\tgot result: %s' % (result,) results.append(result) def handleError(err): sys.stderr.write('\tgot failure: %s' % (err,)) errors.append(err) # this converts the api.login() call to a Twisted thread. # api.login() should return True and is is equivalent to: # api.service.login(username=self.username, password=self.password) deferred = threads.deferToThread(api.login) deferred.addCallbacks(handleResult, handleError) reactor.run() This works as expected and defers return of the api.login() call until it is complete, instead of blocking. But as I said, it doesn't feel right. Thanks in advance for any help, guidance, feedback, criticism, insults, or total solutions.

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• Hibernate HQL and Grails- How do I compare collections?

  - by BurtP

  Hi everyone (my first post!), I have an HQL question (in Groovy/Grails) I was hoping someone could help me with. I have a simple Asset object with a one-to-many Tags collection. class Asset { Set tags static hasMany = [tags:Tag] } class Tag { String name } What I'm trying to do in HQL: A user passes in some tags in params.tags (ex: groovy grails rocks) and wants to return Asset(s) that have those tags, and only those exact tags. Here's my HQL that returns Assets if one or more of the tags are present in an Assets tags: SELECT DISTINCT a FROM Asset a LEFT JOIN a.tags t WHERE t IN (:tags) assetList = Asset.executeQuery( hql, [tags:tokenizedTagListFromParams] The above code works perfect, but its really like an OR. If any of the tag(s) are found, it will return that Asset. I only want to return Assets that have those exact same tags (in number as well). Every time a new tag is created, I new Tag(name:xxx).save() so I can get the Tag instances and unique ID's for each tag that was asked for. I also tried converting the passed in tags to a list of Tag instances with Tag.findByName(t1) for each tag, and also a list of (unique) Tag Id's into the HQL above with no luck. I would appreciate any help/advice. Thank you for your time, Burt

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• Looking for pros/cons of using GWT or JSF

  - by cliff.meyers

  I'm a long time Java developer who has been building UI with Adobe Flex for the past few years. I'm looking to broaden my repertoire with a RIA technology that runs in a plain-old browser, no plug-ins required. I've read a lot about GWT but don't know much about JSF, especially given the varying implementations. Below are some criteria that are important to me as a developer. I'm hoping that the community might be able to tell me about the strengths and weaknesses of GWT and JSF in each: Layout: is it declarative, programmatic or a mix of both? Control library: how rich is the available control library? How easy is it to extend or write custom controls that "play nice" with the built-ins? Javascript: how much of it do I need to write in order to be successful with the framework? Cross-browser: assuming I'm not writing a lot of my own HTML and JS, do the frameworks function equally well in all modern browsers? Tooling: is a rapid edit/refresh cycle available? How easy is it to debug the client and server code? Bookmarking / Browser Navigation: this is a common problem in Flex; does the framework play nicely with these? I would love to hear any other important pros / cons I might not have covered. Thanks!

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• Is this a good job description? What title would you give this position?

  - by Zack Peterson

  Department: Information Technology Reports To: Chief Information Officer Purpose: Company's ________________ is specifically engaged in the development of World Wide Web applications and distributed network applications. This person is concerned with all facets of the software development process and specializes in software product management. He or she contributes to projects in an application architect role and also performs individual programming tasks. Essential Duties & Responsibilities: This person is involved in all aspects of the software development process such as: Participation in software product definitions, including requirements analysis and specification Development and refinement of simulations or prototypes to confirm requirements Feasibility and cost-benefit analysis, including the choice of architecture and framework Application and database design Implementation (e.g. installation, configuration, customization, integration, data migration) Authoring of documentation needed by users and partners Testing, including defining/supporting acceptance testing and gathering feedback from pre-release testers Participation in software release and post-release activities, including support for product launch evangelism (e.g. developing demonstrations and/or samples) and subsequent product build/release cycles Maintenance Qualifications: Bachelor's degree in computer science or software engineering Several years of professional programming experience Proficiency in the general technology of the World Wide Web: Hypertext Transfer Protocol (HTTP) Hypertext Markup Language (HTML) JavaScript Cascading Style Sheets (CSS) Proficiency in the following principles, practices, and techniques: Accessibility Interoperability Usability Security (especially prevention of SQL injection and cross-site scripting (XSS) attacks) Object-oriented programming (e.g. encapsulation, inheritance, modularity, polymorphism, etc.) Relational database design (e.g. normalization, orthogonality) Search engine optimization (SEO) Asynchronous JavaScript and XML (AJAX) Proficiency in the following specific technologies utilized by Company: C# or Visual Basic .NET ADO.NET (including ADO.NET Entity Framework) ASP.NET (including ASP.NET MVC Framework) Windows Presentation Foundation (WPF) Language Integrated Query (LINQ) Extensible Application Markup Language (XAML) jQuery Transact-SQL (T-SQL) Microsoft Visual Studio Microsoft Internet Information Services (IIS) Microsoft SQL Server Adobe Photoshop

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• Need some help with a MySQL subquery count

  - by Ferdy

  I'm running into my own limits of MySQL query skills, so I hope some SQL guru can help out on this one. The situation is as follow: I have images that can be tagged. As you might expect this is stored in three tables: Image Tag Tag_map (maps images to tags) I have a SQL query that calculates the related tags based on a tag id. The query basically checks what other tags were used for images for images using that tag. Example: Image1 tagged as "Bear" Image2 tagged as "Bear" and "Canada" If I throw "Bear" (or its tag id) at the query, it will return "Canada". This works fine. Here's the query: SELECT tag.name, tag.id, COUNT(tag_map.id) as cnt FROM tag_map,tag WHERE tag_map.tag_id = tag.id AND tag.id != '185' AND tag_map.image_id IN (SELECT tag_map.image_id FROM tag_map INNER JOIN tag ON tag_map.tag_id = tag.id WHERE tag.id = '185') GROUP BY tag_map.id LIMIT 0,100 The part I'm stuck with is the count. For each related tag returned, I want to know how many images are in that tag. Currently it always returns 1, even if there are for example 3. I've tried counting different columns all resulting in the same output, so I guess there is a flaw in my thinking.

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• How to reuse results with a schema for end of day stock-data

  - by Vishalrix

  I am creating a database schema to be used for technical analysis like top-volume gainers, top-price gainers etc.I have checked answers to questions here, like the design question. Having taken the hint from boe100 's answer there I have a schema modeled pretty much on it, thusly: Symbol - char 6 //primary Date - date //primary Open - decimal 18, 4 High - decimal 18, 4 Low - decimal 18, 4 Close - decimal 18, 4 Volume - int Right now this table containing End Of Day( EOD) data will be about 3 million rows for 3 years. Later when I get/need more data it could be 20 million rows. The front end will be asking requests like "give me the top price gainers on date X over Y days". That request is one of the simpler ones, and as such is not too costly, time wise, I assume. But a request like " give me top volume gainers for the last 10 days, with the previous 100 days acting as baseline", could prove 10-100 times costlier. The result of such a request would be a float which signifies how many times the volume as grown etc. One option I have is adding a column for each such result. And if the user asks for volume gain in 10 days over 20 days, that would require another table. The total such tables could easily cross 100, specially if I start using other results as tables, like MACD-10, MACD-100. each of which will require its own column. Is this a feasible solution? Another option being that I keep the result in cached html files and present them to the user. I dont have much experience in web-development, so to me it looks messy; but I could be wrong ( ofc!) . Is that a option too? Let me add that I am/will be using mod_perl to present the response to the user. With much of the work on mysql database being done using perl. I would like to have a response time of 1-2 seconds.

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• Speeding up inner-joins and subqueries while restricting row size and table membership

  - by hiffy

  I'm developing an rss feed reader that uses a bayesian filter to filter out boring blog posts. The Stream table is meant to act as a FIFO buffer from which the webapp will consume 'entries'. I use it to store the temporary relationship between entries, users and bayesian filter classifications. After a user marks an entry as read, it will be added to the metadata table (so that a user isn't presented with material they have already read), and deleted from the stream table. Every three minutes, a background process will repopulate the Stream table with new entries (i.e. whenever the daemon adds new entries after the checks the rss feeds for updates). Problem: The query I came up with is hella slow. More importantly, the Stream table only needs to hold one hundred unread entries at a time; it'll reduce duplication, make processing faster and give me some flexibility with how I display the entries. The query (takes about 9 seconds on 3600 items with no indexes): insert into stream(entry_id, user_id) select entries.id, subscriptions_users.user_id from entries inner join subscriptions_users on subscriptions_users.subscription_id = entries.subscription_id where subscriptions_users.user_id = 1 and entries.id not in (select entry_id from metadata where metadata.user_id = 1) and entries.id not in (select entry_id from stream where user_id = 1); The query explained: insert into stream all of the entries from a user's subscription list (subscriptions_users) that the user has not read (i.e. do not exist in metadata) and which do not already exist in the stream. Attempted solution: adding limit 100 to the end speeds up the query considerably, but upon repeated executions will keep on adding a different set of 100 entries that do not already exist in the table (with each successful query taking longer and longer). This is close but not quite what I wanted to do. Does anyone have any advice (nosql?) or know a more efficient way of composing the query?

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• How to make Web Storage persistent in Cordova using JS?

  - by ett

  I have a small quiz app, which is a cross-platform mobile app, that I plan for it to run on Android, iOS, and WP8. I want to store a local highscore, where it will keep track how many points the user had, and if he/she does better than the already stored highscore, update the current highscore. Though, I want the highscore to be persistent, what I mean is, every time the user opens the app I want the last highscore to be present and it to be compared with the new quiz score. Meaning, I don't want the highscore to be deleted after each time the app is closed. I also want for the first time when the app is ran, the highscore to be set to 0, so obviously the first time the user finishes the quiz gets a new highscore. I have those codes so far: scoredb.js // Wait for device API libraries to load document.addEventListener("deviceready", initScoreDB, false); // Device APIs are available function initScoreDB() { window.localStorage.setItem("score", 0); highscore = window.localStorage.getItem("score"); } main.js var correct = 0; var highscore; // In between I have some code that keeps incrementing // correct variable for each correct answer. if (correct > highscore) { window.localStorage.setItem("score", correct); highscore = correct; } It does seem to work okay once the app is started. I did the quiz three times, in the simulator, and it keeps the score as it should. Though, each time I open the app, highscore is reseted to 0. I guess it is due to the fact that I call initScoreDB when the device is ready, and I initialize the score to 0 there and give that value to highscore. Can someone help me to initialize the score to 0 only when the app is ran for the first time, and all the other times to keep the latest highscore as the current highscore and compare it each time with the score that is achieved when the quiz is finished. If someone can help me, I would be glad.

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• C# - How to change window state of Form, on a different thread?

  - by Dodi300

  Hello. Does anyone know how I can chage the window state of a form, from another thread? This is the code I'm using: private void button4_Click(object sender, EventArgs e) { string pathe = label1.Text; string name = Path.GetFileName(pathe); pathe = pathe.Replace(name, ""); string runpath = label2.Text; Process process; process = new Process(); process.EnableRaisingEvents = true; process.Exited += new System.EventHandler(process_Exited); process.StartInfo.FileName = @runpath; process.StartInfo.WorkingDirectory = @pathe; process.Start(); WindowState = FormWindowState.Minimized; } private void process_Exited(object sender, EventArgs e) { this.WindowState = FormWindowState.Normal; } It's meant to run a program and minimize, then return to the normal state once the program has closed. Although I get this error "Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on." Any idea how to get this to work? Thanks.

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• Help Me With This Access Query

  - by yae

  I have 2 tables: "products" and "pieces" PRODUCTS idProd product price PIECES id idProdMain idProdChild quant idProdMain and idProdChild are related with the table: "products". Other considerations is that 1 product can have some pieces and 1 product can be a piece. Price product equal a sum of quantity * price of all their pieces. "Products" table contains all products (p EXAMPLE: TABLE PRODUCTS (idProd - product - price) 1 - Computer - 300€ 2 - Hard Disk - 100€ 3 - Memory - 50€ 4 - Main Board - 100€ 5 - Software - 50€ 6 - CDroms 100 un. - 30€ TABLE PIECES (id - idProdMain - idProdChild - Quant.) 1 - 1 - 2 - 1 2 - 1 - 3 - 2 3 - 1 - 4 - 1 WHAT I NEED? I need update the price of the main product when the price of the product child (piece) is changed. Following the previous example, if I change the price of this product "memory" (is a piece too) to 60€, then product "Computer" will must change his price to 320€ How I can do it using queries? Already I have tried this to obatin the price of the main product, but not runs. This query not returns any value: SELECT Sum(products.price*pieces.quant) AS Expr1 FROM products LEFT JOIN pieces ON (products.idProd = pieces.idProdChild) AND (products.idProd = pieces.idProdChild) AND (products.idProd = pieces.idProdMain) WHERE (((pieces.idProdMain)=5)); MORE INFO The table "products" contains all the products to sell that it is in the shop. The table "pieces" is to take a control of the compound products. To know those who are the products children. For example of compound product: computers. This product is composed by other products (motherboard, hard disk, memory, cpu, etc.)

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• how can I parse and group/do stats on user agent strings?

  - by user151841

  I have a database that has the various user-agent strings of visitors to our site. I'd like to do a 'survey' of them to see what browsers our users are using, so that I can know what features I can use in future development. Is there a tool to parse and run statistics on user-agent strings, or a bunch of strings like this? Ideally, I'd like to see a hierarchical grouping of the stats. For instance: Opera/9.80 (Windows Mobile; WCE; Opera Mobi/WMD-50301; U; en) Presto/2.4.13 Version/10.00 Opera/9.80 (J2ME/MIDP; Opera Mini/4.2.14912/1280; U; en) Presto/2.2.0 Opera/9.80 (J2ME/MIDP; Opera Mini/4.2.13918/812; U; en) Presto/2.2.0 Opera/9.64 (Macintosh; Intel Mac OS X; U; en) Presto/2.1.1 Opera/9.60 (J2ME/MIDP; Opera Mini/4.2.13918/786; U; en) Presto/2.2.0 Opera/9.60 (J2ME/MIDP; Opera Mini/4.0.10992/432; U; en) Presto/2.2.0 I'd like to see 6 entries for Opera, broken down into 3 for 9.80, 1 for 9.64 and 2 for 9.60, and so forth for all browsers. Other dimensions, such as OS, would cross the boundaries of the browser version hierarchy, but it might be nice to see also.

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• LinqToSql Select to a class then do more queries

  - by fyjham

  I have a LINQ query running with multiple joins and I want to pass it around as an IQueryable<T> and apply additional filters in other methods. The problem is that I can't work out how to pass around a var data type and keep it strongly typed, and if I try to put it in my own class (EG: .Select((a,b) => new MyClass(a,b))) I get errors when I try to add later Where clauses because my class has no translations into SQL. Is there any way I can do one of the following: Make my class map to SQL? Make the var data-type implement an interface (So I can pass it round as though it's that)? Something I haven't though of that'll solve my issue? Example: public void Main() { using (DBDataContext context = new DBDataContext()) { var result = context.TableAs.Join( context.TableBs, a => a.BID, b => b.ID, (a,b) => new {A = a, B = b} ); result = addNeedValue(result, 4); } } private ???? addNeedValue(???? result, int value) { return result.Where(r => r.A.Value == value); } PS: I know in my example I can flatten out the function easily, but in the real thing it'd be an absolute mess if I tried.

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• BackgroundWorker and instance variables

  - by Alastair Pitts

  One thing that's always confused me is how a BackgroundWorker seems to have thread-safe access to the instance variables of the surrounding class. Given a basic class: public class BackgroundProcessor { public List<int> Items { get; private set; } public BackgroundProcessor(IEnumerable<int> items) { Items = new List<int>(items); } public void DoWork() { BackgroundWorker worker = new BackgroundWorker(); worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted); worker.DoWork += new DoWorkEventHandler(worker_DoWork); worker.RunWorkerAsync(); } void worker_DoWork(object sender, DoWorkEventArgs e) { var processor = new ProcessingClass(); processor.Process(this.Points); //Accessing the instance variable } void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { //Stuff goes here } } Am I erroneous in my assumption the the call to processor.Process(this.Points); is a thread-safe call? How don't I get a cross-thread access violation? I'm sure it's obvious, but it always has confused me.

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• Execute function without sending 'self' to it

  - by Sergey

  Is that possible to define a function without referencing to self this way? def myfunc(var_a,var_b) But so that it could also get sender data, like if I defined it like this: def myfunc(self, var_a,var_b) That self is always the same so it looks a little redundant here always to run a function this way: myfunc(self,'data_a','data_b'). Then I would like to get its data in the function like this sender.fields. UPDATE: Here is some code to understand better what I mean. The class below is used to show a page based on Jinja2 templates engine for users to sign up. class SignupHandler(webapp.RequestHandler): def get(self, *args, **kwargs): utils.render_template(self, 'signup.html') And this code below is a render_template that I created as wrapper to Jinja2 functions to use it more conveniently in my project: def render_template(response, template_name, vars=dict(), is_string=False): template_dirs = [os.path.join(root(), 'templates')] logging.info(template_dirs[0]) env = Environment(loader=FileSystemLoader(template_dirs)) try: template = env.get_template(template_name) except TemplateNotFound: raise TemplateNotFound(template_name) content = template.render(vars) if is_string: return content else: response.response.out.write(content) As I use this function render_template very often in my project and usually the same way, just with different template files, I wondered if there was a way to get rid of having to call it like I do it now, with self as the first argument but still having access to that object.

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• Optimzing TSQL code

  - by adopilot

  My job is the maintain one application which heavy use SQL server (MSSQL2005). Until now middle server stores TSQL codes in XML and send dynamic TSQL queries without using stored procs. As I am able change those XML queries I want to migrate most of my queries to stored procs. Question is folowing: Most of my queries have same Where conditions against one table Sample: Select ..... from .... where .... and (a.vrsta_id = @vrsta_id or @vrsta_id = 0) and (a.podvrsta_id = @podvrsta_id or @podvrsta_id = 0) and (a.podgrupa_2 = @podgrupa2_id or @podgrupa2_id = 0) and ( (a.id in (select art_id from osobina_veze where podosobina_id in (select ado from dbo.fn_ado_param_int(@podosobina)) group by art_id having count(art_id)= @podosobina_count )) or ('0' = @podosobina) ) They also have same where conditions on other table. How I should organize my code ? What is proper way ? Should I make table valued function that I will use in all queries or use #Temp tables and simple inner join my query to that each time when proc executing? or use #temp filed by table valued function ? or leave all queries with this large where clause and hope that index is going to do their jobs. or use WITH(statement)

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• Atomic swap in GNU C++

  - by Steve

  I want to verify that my understanding is correct. This kind of thing is tricky so I'm almost sure I am missing something. I have a program consisting of a real-time thread and a non-real-time thread. I want the non-RT thread to be able to swap a pointer to memory that is used by the RT thread. From the docs, my understanding is that this can be accomplished in g++ with: // global Data *rt_data; Data *swap_data(Data *new_data) { #ifdef __GNUC__ // Atomic pointer swap. Data *old_d = __sync_lock_test_and_set(&rt_data, new_data); #else // Non-atomic, cross your fingers. Data *old_d = rt_data; rt_data = new_data; #endif return old_d; } This is the only place in the program (other than initial setup) where rt_data is modified. When rt_data is used in the real-time context, it is copied to a local pointer. For old_d, later on when it is sure that the old memory is not used, it will be freed in the non-RT thread. Is this correct? Do I need volatile anywhere? Are there other synchronization primitives I should be calling? By the way I am doing this in C++, although I'm interested in whether the answer differs for C. Thanks ahead of time.

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• joining / merging two arrays

  - by Shishant

  I have two arrays like this, actually this is mysql data retrieved from two different servers: $array1 = array ( 0 => array ( 'id' => 1, 'name' => 'somename') , 1 => array ( 'id' => 2, 'name' => 'somename2') ); $array2 = array ( 0 => array ( 'thdl_id' => 1, 'otherdate' => 'spmethings') , 1 => array ( 'thdl_id' => 2, 'otherdate' => 'spmethings22') ); how can i join / merge array so it looks like this $new_array = array ( 0 => array ( 'id' => 1, 'name' => 'somename', 'otherdate' => 'spmethings') , 1 => array ( 'id' => 2, 'name' => 'somename2', 'otherdate' => 'spmethings22') );

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• VS 2008 C++ build output?

  - by STingRaySC

  Why when I watch the build output from a VC++ project in VS do I see: 1Compiling... 1a.cpp 1b.cpp 1c.cpp 1d.cpp 1e.cpp [etc...] 1Generating code... 1x.cpp 1y.cpp [etc...] The output looks as though several compilation units are being handled before any code is generated. Is this really going on? I'm trying to improve build times, and by using pre-compiled headers, I've gotten great speedups for each ".cpp" file, but there is a relatively long pause during the "Generating Code..." message. I do not have "Whole Program Optimization" nor "Link Time Code Generation" turned on. If this is the case, then why? Why doesn't VC++ compile each ".cpp" individually (which would include the code generation phase)? If this isn't just an illusion of the output, is there cross-compilation-unit optimization potentially going on here? There don't appear to be any compiler options to control that behavior (I know about WPO and LTCG, as mentioned above). EDIT: The build log just shows the ".obj" files in the output directory, one per line. There is no indication of "Compiling..." vs. "Generating code..." steps. EDIT: I have confirmed that this behavior has nothing to do with the "maximum number of parallel project builds" setting in Tools - Options - Projects and Solutions - Build and Run. Nor is it related to the MSBuild project build output verbosity setting. Indeed if I cancel the build before the "Generating code..." step, the ".obj" files will not exist for the most recent set of "compiled" files. E.g., if I cancel the build during "c.cpp" above, I will see only "a.obj" and "b.obj".

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• foreignkey problem

  - by realshadow

  Hey, Imagine you have this model: class Category(models.Model): node_id = models.IntegerField(primary_key = True) type_id = models.IntegerField(max_length = 20) parent_id = models.IntegerField(max_length = 20) sort_order = models.IntegerField(max_length = 20) name = models.CharField(max_length = 45) lft = models.IntegerField(max_length = 20) rgt = models.IntegerField(max_length = 20) depth = models.IntegerField(max_length = 20) added_on = models.DateTimeField(auto_now = True) updated_on = models.DateTimeField(auto_now = True) status = models.IntegerField(max_length = 20) node = models.ForeignKey(Category_info, verbose_name = 'Category_info', to_field = 'node_id' The important part is the foreignkey. When I try: Category.objects.filter(type_id = 15, parent_id = offset, status = 1) I get an error that get returned more than category, which is fine, because it is supposed to return more than one. But I want to filter the results trough another field, which would be type id (from the second Model) Here it is: class Category_info(models.Model): objtree_label_id = models.AutoField(primary_key = True) node_id = models.IntegerField(unique = True) language_id = models.IntegerField() label = models.CharField(max_length = 255) type_id = models.IntegerField() The type_id can be any number from 1 - 5. I am desparately trying to get only one result where the type_id would be number 1. Here is what I want in sql: SELECT c.*, ci.* FROM category c JOIN category_info ci ON (c.node_id = ci.node_id) WHERE c.type_id = 15 AND c.parent_id = 50 AND ci.type_id = 1 Any help is GREATLY appreciated. Regards

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• How do you save and retrieve a Key/IV pair securely?

  - by Shawn Steward

  I'm using VB.Net's RijndaelManaged (RM) to encrypt files, using the RM.GenerateKey and RM.GenerateIV methods to generate the Key and IV and encrypting the file using the CryptoStream class. I'm planning on saving this Key and IV to a file and want to make sure I'm doing it the right way. I am combining the IV+Key, and encrypting that with my RSA Public key and writing it out to a file. Then, to decrypt I use the RSA Private key on this file to get the IV+Key, split them up and set RM.Key and RM.IV to these values and run the decryptor. Is this the best method to accomplish this, or is there a preferred method for saving the IV & Key? Also, what's the best way to construct and deconstruct the byte array? I used the .Concat method to join them together and that seems to work well but I can't seem to find something as easy to deconstruct it. I played with the .Take method that takes the first x # of bytes and it works for the first part but can't find anything that gets the rest of it.

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• Vector ArrayIndexOutOfBounds

  - by Esmond

  I'm having an ArrayIndexOutofBounds exception with the following code. The exception is thrown at the line where Node nodeJ = vect.get(j) but it does not make sense to me since j is definitely smaller than i and Node nodeI = vect.get(i) does not throw any exception. any help is appreciated. public static Vector join(Vector vect) throws ItemNotFoundException { Vector<Node> remain = vect; for (int i = 1; i < vect.size(); i++) { Node nodeI = vect.get(i); for (int j = 0; j < i; j++) {//traverse the nodes before nodeI Node nodeJ = vect.get(j); if (nodeI.getChild1().getSeq().equals(nodeJ.getSeq())) { nodeI.removeChild(nodeJ); nodeI.setChild(nodeJ); remain.remove(j); } if (nodeI.getChild2().getSeq().equals(nodeJ.getSeq())) { nodeI.removeChild(nodeJ); nodeI.setChild(nodeJ); remain.remove(j); } } } return remain; }

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• Can threads safely read variables set by VCL events?

  - by Tom1952

  Is it safe for a thread to READ a variable set by a Delphi VCL event? When a user clicks on a VCL TCheckbox, the main thread sets a boolean to the checkbox's Checked state. CheckboxState := CheckBox1.Checked; At any time, a thread reads that variable if CheckBoxState then ... It doesn't matter if the thread "misses" a change to the boolean, because the thread checks the variable in a loop as it does other things. So it will see the state change eventually... Is this safe? Or do I need special code? Is surrounding the read and write of the variable (in the thread and main thread respectively) with critical code calls necessary and sufficient? As I said, it doesn't matter if the thread gets the "wrong" value, but I keep thinking that there might be a low-level problem if one thread tries to read a variable while the main thread is in the middle of writing it, or vice versa. My question is similar to this one: http://stackoverflow.com/questions/1353096/cross-thread-reading-of-a-variable. (Also related to my previous question: http://stackoverflow.com/questions/2449183/using-entercriticalsection-in-thread-to-update-vcl-label)

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