Search Results

Search found 3996 results on 160 pages for 'operations'.

Page 126/160 | < Previous Page | 122 123 124 125 126 127 128 129 130 131 132 133  | Next Page >

• Syncing magento database froms development to production

  - by ringerce

  I use git for version control. I have a development, staging and production environment. When I finish in development I push to staging for review by the client. When approved, I push changes from staging to production. That works fine as long as there is no database changes. What happens if I install modules via Magento connect on local development and it makes database modifications. How would I push those changes up to the production server since the production server is always changing? Edit: I wrote two shell scripts. One that pulls the production database down to my development server, replaces base url with develpment url and updates my development db accordingly. It also leaves the production sql dump behind to be added to my git repo. I'm not really sure if it's beneficial to keep the raw dumps in source control but I'm going to try it out. The second scripts moves the development database up to staging and essentially performs the same operations as the first. Now when it comes time to move to production I pull the updated production repo into the production server and allow magento to do it's thing. I also started using SQLYog recently and it has a database comparison wizard which will give me the differences in my development and production databases and allow me to merge the changes in selectively. It always creates a migration script that I added to source control as well. If anything goes wrong I can run the comparison to see if anything was missed. Does this sounds like a decent workflow to you guys?

  Read the article

• C++ iterators, default initialization and what to use as an uninitialized sentinel.

  - by Hassan Syed

  The Context I have a custom template container class put together from a map and vector. The map resolves a string to an ordinal, and the vector resolves an ordinal (only an initial string to ordinal lookup is done, future references are to the vector) to the entry. The entries are modified intrusively to contain a a bool "assigned" and an iterator_type which is a const_iterator to the container class's map. My container class will use RCF's serialization code (which models boost::serialization) to serialize my container classes to nodes in a network. Serializing iterator's is not possible, or a can of worms, and I can easily regenerate them onces the vectors and maps are serialized on the remote site. The Question I need to default initialize, and be able to test that the iterator has not been assigned to (if it is assigned it is valid, if not it is invalid). Since map iterators are not invalidated upon operations performed on it (unless of course items are removed :D) am I to assume that map<x,y>::end() is a valid sentinel (regardless of the state of the map -- i.e., it could be empty) to initialize to ? I will always have access to the parent map, I'm just unsure wheather end() is the same as the map contents change. I don't want to use another level of indirection (--i.e., boost::optional) to achieve my goal, I'd rather forego compiler checks to correct logic, but it would be nice if I didn't need to. Misc This question exists, but most of its content seems non-sense. Assigning a NULL to an iterator is invalid according to g++ and clang++. This is another similar question, but it focuses on the common use-cases of iterators, which generally tends to be using the iterator to iterate, ofcourse in this use-case the state of the container isn't meant to change whilst iteration is going on.

  Read the article

• Should java try blocks be scoped as tightly as possible?

  - by isme

  I've been told that there is some overhead in using the Java try-catch mechanism. So, while it is necessary to put methods that throw checked exception within a try block to handle the possible exception, it is good practice performance-wise to limit the size of the try block to contain only those operations that could throw exceptions. I'm not so sure that this is a sensible conclusion. Consider the two implementations below of a function that processes a specified text file. Even if it is true that the first one incurs some unnecessary overhead, I find it much easier to follow. It is less clear where exactly the exceptions come from just from looking at statements, but the comments clearly show which statements are responsible. The second one is much longer and complicated than the first. In particular, the nice line-reading idiom of the first has to be mangled to fit the readLine call into a try block. What is the best practice for handling exceptions in a funcion where multiple exceptions could be thrown in its definition? This one contains all the processing code within the try block: void processFile(File f) { try { // construction of FileReader can throw FileNotFoundException BufferedReader in = new BufferedReader(new FileReader(f)); // call of readLine can throw IOException String line; while ((line = in.readLine()) != null) { process(line); } } catch (FileNotFoundException ex) { handle(ex); } catch (IOException ex) { handle(ex); } } This one contains only the methods that throw exceptions within try blocks: void processFile(File f) { FileReader reader; try { reader = new FileReader(f); } catch (FileNotFoundException ex) { handle(ex); return; } BufferedReader in = new BufferedReader(reader); String line; while (true) { try { line = in.readLine(); } catch (IOException ex) { handle(ex); break; } if (line == null) { break; } process(line); } }

  Read the article

• Pseudo-quicksort time complexity

  - by Ord

  I know that quicksort has O(n log n) average time complexity. A pseudo-quicksort (which is only a quicksort when you look at it from far enough away, with a suitably high level of abstraction) that is often used to demonstrate the conciseness of functional languages is as follows (given in Haskell): quicksort :: Ord a => [a] -> [a] quicksort [] = [] quicksort (p:xs) = quicksort [y | y<-xs, y<p] ++ [p] ++ quicksort [y | y<-xs, y>=p] Okay, so I know this thing has problems. The biggest problem with this is that it does not sort in place, which is normally a big advantage of quicksort. Even if that didn't matter, it would still take longer than a typical quicksort because it has to do two passes of the list when it partitions it, and it does costly append operations to splice it back together afterwards. Further, the choice of the first element as the pivot is not the best choice. But even considering all of that, isn't the average time complexity of this quicksort the same as the standard quicksort? Namely, O(n log n)? Because the appends and the partition still have linear time complexity, even if they are inefficient.

  Read the article

• Detaching all entities of T to get fresh data

  - by Goran

  Lets take an example where there are two type of entites loaded: Product and Category, Product.CategoryId - Category.Id. We have available CRUD operations on products (not Categories). If on another screen Categories are updated (or from another user in the network), we would like to be able to reload the Categories, while preserving the context we currently use, since we could be in the middle of editing data, and we do not want changes to be lost (and we cannot depend on saving, since we have incomplete data). Since there is no easy way to tell EF to get fresh data (added, removed and modified), we thought of twp possible ways: 1) Getting products attached to context, and categories detached from context. This would mean that we loose the ability to access Product.Category.Name, which we do sometimes require, so we would need to manually resolve it (example when printing data). 2) detaching / attaching all Categories from current context. Context.ChangeTracker.Entries().Where(x => x.Entity.GetType() == typeof(T)).ForEach(x => x.State = EntityState.Detached); And then reload the categories, which will get fresh data. Do you find any problem with this second approach? We understand that this will require all constraints to be put on foreign keys, and not navigation properties, since when detaching all Categories, Product.Category navigation properties would be reset to null also. Also, there could be a potential performance problem, which we did not test, since there could be couple of thousand products loaded, and all would need to resolve navigation property when reloading. Which of the two do you prefer, and is there a better way (EF6 + .NET 4.0)?

  Read the article

• Problems migrating databinding in VB.NET from Winforms to ASP.NET 2.0

  - by David

  And this was supposed to be so easy... I have existing business and data access layers that handle the retrieval and update of the data in question. These work great with the existing Winforms application (.Net V2.0) Now, in trying to write a new web-based UI, I'm running into all sorts of problems (last time I wrote asp.net code was in 1.1). Specifically, I can't data bind a text box to a business object. Oh, sure there's the ObjectDataSource but that wants to know how to do CRUD operations on the data. What I'm looking for is something that acts like the 'classic' binding objects so that, in my code, it's as simple as retrieving the object and doing a a refresh. The data component like FormView and DetailsView are so generic-looking that it's ridiculous. The existing application would have tabbed dialogs, text boxes grouped by panels, etc. On top of that, I have a directive to use master pages and unless one control causes it, I can't seem to get the content section to expand. I can't just put a text box 'below' the bottom of "Content1" and have it resize the content section - which gives me the same results as an earlier question I posted when the footer wasn't being 'pushed down' - relative position solved that but doesn't seem to solve it with placing small text boxes in the area. What I want is fairly simple. Something like: bindingobject.datasource = businessdataobject bindingobject.refresh ...and have the text boxes refresh with the new values. Likewise to have 'businessdataobject' properties updated as the user enters new data. I was able to do this with the GridView (grdRequests.DataSource = lstRequests) by making a list of asp:BoundField tags inside the collection of the GridView. Am I tilting at windmills here?

  Read the article

• java GC periodically enters into several full GC cycles

  - by Peter

  Environment: sun JDK 1.6.0_16 vm settings: -XX:+DisableExplicitGC -XX:+UseConcMarkSweepGC -Xms1024 -Xmx1024M -XX:MaxNewSize=448m -XX:NewSize=448m -XX:SurvivorRatio=4(6 also checked) -XX:MaxPermSize=128M OS: windows server 2003 processor: 4 cores of INTEL XEON 5130, 2000 Hz my application description: high intensity of concurrent(java 5 concurrency used) operations completed each time by commit to oracle. it's about 20-30 threads run non stop, doing tasks. application runs in JBOSS web container. My GC starts work normally, I see a lot of small GCs and all that time CPU shows good load, like all 4 cores loaded to 40-50%, CPU graph is stable. Then , after 1 min of good work, CPU starts drop to 0% on 2 cores from 4, it's graph becomes unstable, goes up and down("teeth"). I see, that my threads work slower(I have monitoring), I see that GC starts produce a lot of FULL GC during that time and next 4-5 minutes this situation remains as is, then for short period of time, like 1 minute, it gets back to normal situation, but shortly after that all bad thing repeats. Question: Why I have so frequent full GC??? How to prevent that? I played with SurvivorRatio - does not help. I noticed, that application behaves normally until first FULL GC occurs, while I have enough memory. Then it runs badly. my GC LOG: starts good then long period of FULL GCs(many of them) 1027.861: [GC 942200K-623526K(991232K), 0.0887588 secs] 1029.333: [GC 803279K(991232K), 0.0927470 secs] 1030.551: [GC 967485K-625549K(991232K), 0.0823024 secs] 1030.634: [GC 625957K(991232K), 0.0763656 secs] 1033.126: [GC 969613K-632963K(991232K), 0.0850611 secs] 1033.281: [GC 649899K(991232K), 0.0378358 secs] 1035.910: [GC 813948K(991232K), 0.3540375 secs] 1037.994: [GC 967729K-637198K(991232K), 0.0826042 secs] 1038.435: [GC 710309K(991232K), 0.1370703 secs] 1039.665: [GC 980494K-972462K(991232K), 0.6398589 secs] 1040.306: [Full GC 972462K-619643K(991232K), 3.7780597 secs] 1044.093: [GC 620103K(991232K), 0.0695221 secs] 1047.870: [Full GC 991231K-626514K(991232K), 3.8732457 secs] 1053.739: [GC 942140K(991232K), 0.5410483 secs] 1056.343: [Full GC 991232K-634157K(991232K), 3.9071443 secs] 1061.257: [GC 786274K(991232K), 0.3106603 secs] 1065.229: [Full GC 991232K-641617K(991232K), 3.9565638 secs] 1071.192: [GC 945999K(991232K), 0.5401515 secs] 1073.793: [Full GC 991231K-648045K(991232K), 3.9627814 secs] 1079.754: [GC 936641K(991232K), 0.5321197 secs]

  Read the article

• Lookup table size reduction

  - by Ryan

  Hello: I have an application in which I have to store a couple of millions of integers, I have to store them in a Look up table, obviously I cannot store such amount of data in memory and in my requirements I am very limited I have to store the data in an embebedded system so I am very limited in the space, so I would like to ask you about recommended methods that I can use for the reduction of the look up table. I cannot use function approximation such as neural networks, the values needs to be in a table. The range of the integers is not known at the moment. When I say integers I mean a 32 bit value. Basically the idea is use some copmpression method to reduce the amount of memory but without losing many precision. This thing needs to run in hardware so the computation overhead cannot be very high. In my algorithm I have to access to one value of the table do some operations with it and after update the value. In the end what I should have is a function which I pass an index to it and then I get a value, and after I have to use another function to write a value in the table. I found one called tile coding http://www.cs.ualberta.ca/~sutton/book/8/node6.html, this one is based on several look up tables, does anyone know any other method?. Thanks.

  Read the article

• Looking for all-in-one drm/installer/CD creation kit.

  - by user30997

  The company I work for has a download manager in place that handles distribution, DRM, installation of our products - when a user gets them off our website. However, we're using an clunky system for packaging and protecting our products when we do press releases or make retail CDs. Part of the antiquation problem is the fact that the automated system that works with the installer- and DRM-creation software we have is a disaster that needs to be put out of my misery. The list of products that we currently produce, that I would like a new system MUST be capable of producing: Retail CDs, with a certain level of obfuscation to make copying difficult. Downloadable installers that time out after a few hours of use of the product. After the time has expired, removing and reinstalling the product will leave you still blocked from use. Installers that will fail to work after a certain date. I'd love to be able to just feed a tool the directory where a complete product resides and have the installer generated with a couple command-line operations. (The command-line issue is non-negotiable this well be called by an automated tool.) A single-solution package would be far preferable. Software with royalty-based or per-unit based licensing is not an option.

  Read the article

• Proftpd log issue

  - by ggenov

  Hi, I'm developing an application where I read the current changes in certain folders on the server via FTP. The problem is that on files which begin with non-standart symbols as "~" the FTP server doesn't write full path name in the log Here is a part of my log: myuser [14/Jun/2010:20:50:11 +0000] ::ffff:217.145.84.66 [STOR] [/home/myuser/public_html/galleries/~ajax-loader.gif] myuser [14/Jun/2010:20:50:11 +0000] ::ffff:217.145.84.66 [MFMT] [-] myuser [14/Jun/2010:20:50:11 +0000] ::ffff:217.145.84.66 [MLST] [-] myuser [14/Jun/2010:23:50:11 +0300] ::ffff:217.145.84.66 [MLST] [-] myuser [14/Jun/2010:20:50:11 +0000] ::ffff:217.145.84.66 [MLST] [-] myuser [14/Jun/2010:20:50:12 +0000] ::ffff:217.145.84.66 [PASV] [-] myuser [14/Jun/2010:20:50:12 +0000] ::ffff:217.145.84.66 [STOR] [/home/myuser/public_html/galleries/~~ajax-loader.gif                                                                                            ] myuser [14/Jun/2010:20:50:12 +0000] ::ffff:217.145.84.66 [MFMT] [-] myuser [14/Jun/2010:20:50:12 +0000] ::ffff:217.145.84.66 [MLST] [-] myuser [14/Jun/2010:23:50:12 +0300] ::ffff:217.145.84.66 [MLST] [-] myuser [14/Jun/2010:23:50:22 +0300] ::ffff:217.145.84.66 [DELE] [] As you can see, all operations work very well except [DELE] command. My proftpd.conf file and its log's settings: LogFormat               default "%U %t %a [%m] [%f]" ExtendedLog             /var/log/proftpd ALL default #SystemLog               /var/log/proftpd ALL default #TransferLog             /var/log/proftpd ALL default Does anybody have a solution for this issue ?

  Read the article

• Which source control paradigm and solution to embed in a custom editor application?

  - by Greg Harman

  I am building an application that manages a number of custom objects, which may be edited concurrently by multiple users (using different instances of the application). These objects have an underlying serialized representation, and my plan is to persist them (through my application UI) in an external source control system. Of course this implies that my application can check the current version of an object for updates, a merging interface for each object, etc. My question is what source control paradigm(s) and specific solution(s) to support and why. The way I (perhaps naively) see the source control world is three general paradigms: Single-repository, locked access (MS SourceSafe) Single-repository, concurrent access (CVS/SVN) Distributed (Mercurial, Git) I haven't heard of anyone using #1 for quite a number of years, so I am planning to disregard this case altogether (unless I get a compelling argument otherwise). However, I'm at a loss as to whether to support #2 or #3, and which specific implementations. I'm concerned that the use paradigms are subtly different enough that I can't adequately capture basic operations in a single UI. The last bit of information I should convey is that this application is intended to be deployed in a commercial setting, where a source control system may already be in use. I would prefer not to support more than one solution unless it's really a deal-breaker, so wide adoption in a corporate setting is a plus.

  Read the article

• Ruby Design Problem for SQL Bulk Inserter

  - by crunchyt

  This is a Ruby design problem. How can I make a reusable flat file parser that can perform different data scrubbing operations per call, return the emitted results from each scrubbing operation to the caller and perform bulk SQL insertions? Now, before anyone gets narky/concerned, I have written this code already in a very unDRY fashion. Which is why I am asking any Ruby rockstars our there for some assitance. Basically, everytime I want to perform this logic, I create two nested loops, with custom processing in between, buffer each processed line to an array, and output to the DB as a bulk insert when the buffer size limit is reached. Although I have written lots of helpers, the main pattern is being copy pasted everytime. Not very DRY! Here is a Ruby/Pseudo code example of what I am repeating. lines_from_file.each do |line| line.match(/some regex/).each do |sub_str| # Process substring into useful format # EG1: Simple gsub() call # EG2: Custom function call to do complex scrubbing # and matching, emitting results to array # EG3: Loop to match opening/closing/nested brackets # or other delimiters and emit results to array end # Add processed lines to a buffer as SQL insert statement @buffer << PREPARED INSERT STATEMENT # Flush buffer when "buffer size limit reached" or "end of file" if sql_buffer_full || last_line_reached @dbc.insert(SQL INSERTS FROM BUFFER) @buffer = nil end end I am familiar with Proc/Lambda functions. However, because I want to pass two separate procs to the one function, I am not sure how to proceed. I have some idea about how to solve this, but I would really like to see what the real Rubyists suggest? Over to you. Thanks in advance :D

  Read the article

• How can I find out if the MainActivity is being paused from my Java class?

  - by quinestor

  I am using motion sensor detection in my application. My design is this: a class gets the sensor services references from the main activity and then it implements SensorEventListener. That is, the MainActivity does not listen for sensor event changes: public void onCreate(Bundle savedInstanceState) { // ... code mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE); mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); // The following is my java class, it does not extends any android fragment/activty mShakeUtil = new ShakeUtil(mSensorManager,mAccelerometer,this); // ..more code.. } I can't redesign ShakeUtil so it is a fragment nor activity, unfortunately. Now to illustrate the problem consider: MainActivity is on its way to be destroyed/paused. I.e screen rotation ShakeUtil's onSensorChanged(SensorEvent event) gets called in the process.. One of the things that happen inside onSensorChanged is a dialog interaction, which gives the error: java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState When the previous happens between MainActivity's onSaveInstanceState and onPause. I know this can be prevented if I successfully detect that MainActivity is being pause in ShakeUtil. How can I detect that MainActivity is being paused or onSaveInstanceState was called from ShakeUtil? Alternatively, how can I avoid this issue without making Shakeutil extend activity? So far I have tried with flag variables but that isn't good enough, I guess these are not atomic operations. I tried using Activity's isChangingConfigurations(), but I get an undocummented "NoSuchMethodFound" error.. I am unregistering the sensors by calling ShakeUtil when onPause in main ACtivity

  Read the article

• Recursive Iterators

  - by soandos

  I am having some trouble making an iterator that can traverse the following type of data structure. I have a class called Expression, which has one data member, a List<object>. This list can have any number of children, and some of those children might be other Expression objects. I want to traverse this structure, and print out every non-list object (but I do want to print out the elements of the list of course), but before entering a list, I want to return "begin nest" and after I just exited a list, I want to return "end nest". I was able to do this if I ignored the class wherever possible, and just had List<object> objects with List<object> items if I wanted a subExpression, but I would rather do away with this, and instead have an Expressions as the sublists (it would make it easier to do operations on the object. I am aware that I could use extension methods on the List<object> but it would not be appropriate (who wants an Evaluate method on their list that takes no arguments?). The code that I used to generate the origonal iterator (that works) is: public IEnumerator GetEnumerator(){ return theIterator(expr).GetEnumerator(); } private IEnumerable theIterator(object root) { if ((root is List<object>)){ yield return " begin nest "; foreach (var item in (List<object>)root){ foreach (var item2 in theIterator(item)){ yield return item2; } } yield return " end nest "; } else yield return root; } A type swap of List<object> for expression did not work, and lead to a stackOverflow error. How should the iterator be implemented? Update: Here is the swapped code: public IEnumerator GetEnumerator() { return this.GetEnumerator(); } private IEnumerable theIterator(object root) { if ((root is Expression)) { yield return " begin nest "; foreach (var item in (Expression)root) { foreach (var item2 in theIterator(item)) yield return item2; } yield return " end nest "; } else yield return root; }

  Read the article

• Building a control-flow graph from an AST with a visitor pattern using Java

  - by omegatai

  Hi guys, I'm trying to figure out how to implement my LEParserCfgVisitor class as to build a control-flow graph from an Abstract-Syntax-Tree already generated with JavaCC. I know there are tools that already exist, but I'm trying to do it in preparation for my Compilers final. I know I need to have a data structure that keeps the graph in memory, and I want to be able to keep attributes like IN, OUT, GEN, KILL in each node as to be able to do a control-flow analysis later on. My main problem is that I haven't figured out how to connect the different blocks together, as to have the right edge between each blocks depending on their nature: branch, loops, etc. In other words, I haven't found an explicit algorithm that could help me build my visitor. Here is my empty Visitor. You can see it works on basic langage expressions, like if, while and basic operations (+,-,x,^,...) public class LEParserCfgVisitor implements LEParserVisitor { public Object visit(SimpleNode node, Object data) { return data; } public Object visit(ASTProgram node, Object data) { data = node.childrenAccept(this, data); return data; } public Object visit(ASTBlock node, Object data) { } public Object visit(ASTStmt node, Object data) { } public Object visit(ASTAssignStmt node, Object data) { } public Object visit(ASTIOStmt node, Object data) { } public Object visit(ASTIfStmt node, Object data) { } public Object visit(ASTWhileStmt node, Object data) { } public Object visit(ASTExpr node, Object data) { } public Object visit(ASTAddExpr node, Object data) { } public Object visit(ASTFactExpr node, Object data) { } public Object visit(ASTMultExpr node, Object data) { } public Object visit(ASTPowerExpr node, Object data) { } public Object visit(ASTUnaryExpr node, Object data) { } public Object visit(ASTBasicExpr node, Object data) { } public Object visit(ASTFctExpr node, Object data) { } public Object visit(ASTRealValue node, Object data) { } public Object visit(ASTIntValue node, Object data) { } public Object visit(ASTIdentifier node, Object data) { } } Can anyone give me a hand? Thanks!

  Read the article

• QueryHistory against a codeplex project hangs indefinitely

  - by Robaticus

  I'm working on a TFS utility that gets the changesets for a particular project in TFS. I've got a home TFS 2010 server which I primarily use for testing, but I decided to give it a try against a codeplex project to which I contribute. That way, I can test functionality against a larger number of changesets than I have locally. While it works fine in my environment, heading out over the wire to codeplex has left me stumped. My application queries the history, but then, when trying to iterate through the history (which is when it lazy-loads the IEnumerable), my application hangs. Looking at Intellitrace, I see a couple of "first chance" exceptions that the "item doesn't exist at the specified version"-- which is patently not true, as I'm trying to get history for "$/" at VersionSpec.Latest. I also see two or three consecutive server 500 errors being returned to me after forcing debugging to pause. Other operations (like GetItems() ) work fine, so I'm pretty sure authentication isn't an issue. Any thoughts? Here's the code: IEnumerable items = vcs.QueryHistory("$/", VersionSpec.Latest, 1, RecursionType.None, null, null, null, 5, true, false); List<ChangesetItem> returnList = new List<ChangesetItem>(); foreach (Changeset cs in items) //hangs here on first iteraiton { ChangesetItem newItem = new ChangesetItem() { ChangesetId = cs.ChangesetId, //ChangesetNote = cs.CheckinNote.Values[0].Value, Comment = cs.Comment, Committer = cs.Committer, CreationDate = cs.CreationDate }; returnList.Add(newItem); }

  Read the article

• Delphi Pascal / Windows API - Small problem with SetFilePointerEx and parameter FILE_END

  - by SuicideClutchX2

  I know I am about to be slapped by at least one person who was helping me with this API. Alright I have been able to use SetFilePointerEx just fine, when setting the position only. SetFilePointerEx(PD,512,@PositionVar,FILE_BEGIN); SetFilePointerEx(PD,0,@PositionVar,FILE_CURRENT); Both work, I can set positions and even check my current one. But when I set FILE_END as per the documentation no matter what the second parameter is and whether or not i provide a pointer for the third parameter it fails even on a valid handle that many other operations are able to use without fail. For Example: SetFailed := SetFilePointerEx(PD,0,@PositionVar,FILE_END); SetFailed := SetFilePointerEx(PD,0,nil,FILE_END); Whatever I put it fails. I am working with a handle to a physical disk and it most definitely has an end. SetFilePointer works just fine its just a little more trouble than I would like. Its not the end of the world, but whats happening.

  Read the article

• Using hashing to group similar records

  - by Neil Dobson

  I work for a fulfillment company and we have to pack and ship many orders from our warehouse to customers. To improve efficiency we would like to group identical orders and pack these in the most optimum way. By identical I mean having the same number of order lines containing the same SKUs and same order quantities. To achieve this I was thinking about hashing each order. We can then group by hash to quickly see which orders are the same. We are moving from an Access database to a PostgreSQL database and we have .NET based systems for data loading and general order processing systems, so we can either do the hashing during the data loading or hand this task over to the DB. My question firstly is should the hashing be managed by DB, possibly using triggers, or should the hash be created on-the-fly using a view or something? And secondly would it be best to calculate a hash for each order line and then to combine these to find an order-level hash for grouping, or should I just use a trigger for all CRUD operations on the order lines table which re-calculates a single hash for the entire order and store the value in the orders table? TIA

  Read the article

• Compact data structure for storing a large set of integral values

  - by Odrade

  I'm working on an application that needs to pass around large sets of Int32 values. The sets are expected to contain ~1,000,000-50,000,000 items, where each item is a database key in the range 0-50,000,000. I expect distribution of ids in any given set to be effectively random over this range. The operations I need on the set are dirt simple: Add a new value Iterate over all of the values. There is a serious concern about the memory usage of these sets, so I'm looking for a data structure that can store the ids more efficiently than a simple List<int>or HashSet<int>. I've looked at BitArray, but that can be wasteful depending on how sparse the ids are. I've also considered a bitwise trie, but I'm unsure how to calculate the space efficiency of that solution for the expected data. A Bloom Filter would be great, if only I could tolerate the false negatives. I would appreciate any suggestions of data structures suitable for this purpose. I'm interested in both out-of-the-box and custom solutions. EDIT: To answer your questions: No, the items don't need to be sorted By "pass around" I mean both pass between methods and serialize and send over the wire. I clearly should have mentioned this. There could be a decent number of these sets in memory at once (~100).

  Read the article

• Ember Data Sycn - LocalStorage+REST+RealTime+Online/Offline

  - by Miguel Madero

  We have a combination of requirements in terms o data access. Pre-load some reference data. We need reference data to survive browser restarts instead of just living in memory to avoid loading it all the time. I'm currently using the LocalStorageAdapter for that. Once we have it, we would like to sync changes (polling or using Socket.IO in the background and updating the LocalStorage could do the trick) There're other models that are more transactional, where we would need to directly go to the Server and get/save them. It would be nice to use something like the RESTAdapter for that. Lastly, there're some operations that should work off-line and changes should be synced later. To make it more concrete: * We pre-load vendor and "favorite products" into Local Storage. We work offline with those. * We need to sync server changes to vendor and product information. * If they search the full catalog, that requires them to be online. * When offline, we need to allow users to add something to their cart or even submit and order. We would like to queue this action and submit it when they have an Internet Connection. So a few questions are derived from this: * Is there a way to user RESTAdapter in combination with LocalStorage? * Is there some Socket.IO support? (Happy to do this part manually) * Is there Queueing support? Ideally at the Ember-Data level. I know we will have to do a lot of this manually and pull together the different lego pieces, but I wanted to ask for some perspective from experience Ember devs.

  Read the article

• How can I improve the performance of LinqToSql queries that use EntitySet properties?

  - by DanM

  I'm using LinqToSql to query a small, simple SQL Server CE database. I've noticed that any operations involving sub-properties are disappointingly slow. For example, if I have a Customer table that is referenced by an Order table, LinqToSql will automatically create an EntitySet<Order> property. This is a nice convenience, allowing me to do things like Customer.Order.Where(o => o.ProductName = "Stopwatch"), but for some reason, SQL Server CE hangs up pretty bad when I try to do stuff like this. One of my queries, which isn't really that complicated takes 3-4 seconds to complete. I can get the speed up to acceptable, even fast, if I just grab the two tables individually and convert them to List<Customer> and List<Order>, then join then manually with my own query, but this is throwing out a lot of what makes LinqToSql so appealing. So, I'm wondering if I can somehow get the whole database into RAM and just query that way, then occasionally save it. Is this possible? How? If not, is there anything else I can do to boost the performance besides resorting to doing all the joins manually? Note: My database in its initial state is about 250K and I don't expect it to grow to more than 1-2Mb. So, loading the data into RAM certainly wouldn't be a problem from a memory point of view. Update Here are the table definitions for the example I used in my question: create table Order ( Id int identity(1, 1) primary key, ProductName ntext null ) create table Customer ( Id int identity(1, 1) primary key, OrderId int null references Order (Id) )

  Read the article

• Is it possible to definitively identify whether a DML command was issued from a stored procedure?

  - by Ed Harper

  I have inherited a SQL Server 2008 database to which calling applications have access through stored procedures. Each table in the database has a shadow audit table into which Insert/Update/Delete operations for are logged. Performance testing on populating the audit tables showed that inserting the audit records using OUTPUT clauses was 20% or so faster than using triggers, so this has been implemented in the stored procedures. However, because this design cannot track changes made directly to the tables through DML statements issued directly against the tables, triggers have also been implemented which use the value of @@NESTLEVEL to determine whether or not to run the trigger (the assumption being that all DML run through stored procedures will have @@NESTLEVEL 1). i.e. the body of the trigger code looks something like: IF @@NESTLEVEL = 1 -- implies call is direct sql so generate history from here BEGIN ... insert into audit table This design is flawed because it won't track updates where DML statements are executed in dynamic SQL, or any other context where @@NESTLEVEL is raised above 1. Can anyone suggest a completely reliable method we can use in the triggers to execute them only if not triggered by a stored procedure? Or is this (as I suspect) not possible?

  Read the article

• Accessing a share point site using the object model.

  - by Prashanth

  Hi I am trying to access a share point site using the SP object model from a console application. I am trying to do something like this.. SPSite site = new SPSite(sitePath) //Operations go here This works fine when the share point site and the console app are on the same machine. However when the console app and the site are on different machines, I get an error "The Web application at "http://server/url" could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing content, the system administrator may need to add a new request URL mapping to the intended application" Here are the things that I have already done: 1) I have tried accessing the site via both IP address as well as machine name, assuming that it could be a DNS resolution issue. 2) Initially I impersonated using a farm admin account, still i could not access. Then I added myself as the farm admin, still no joy. 4) The site is accessible via IE. So it is not a permission issue I guess. 5) I have tried almost all the solutions suggested by various links obtained by googling the error message. I am trying this on share point 2010. A similar issue occurs on 2007 also. Sometimes its kind of frustrating to do SharePoint development , since I get the feeling of stumbling from one error to the next, with no clue as to what could be wrong and the error messages not being helpful in the least :(

  Read the article

• Another rsAccessDenied problem with SSRS

  - by Rich.Carpenter

  I've read through a lot of posts regarding the problem, but none of the proposed solutions have worked for me. I continue to get an error stating, "The permissions granted to user '\Rich' are insufficient for performing this operation. (rsAccessDenied)." If I am logged in as the local administrator account, entering the Reporting Services URL in IE doesn't give me that error, but it takes me to a blank page. I haven't been able to get to a SSRS home page at all. Order of operations: I installed and patched Windows 7 Ultimate 64-bit I installed SQL Server Express 2008 with Advanced Services using the MS web installer. I downloaded and installed SP1 for SQL Server Express 2008. I've tried running IE as administrator, adding local machine to trusted sites, and just about every other suggestion I've found. I even ran the entire installation logged in as the local administrator. Nothing seems to work. Could someone please tell me, considering the above installation process, what I should expect to do after to make this work?

  Read the article

• PHP Socket Server vs node.js: Web Chat

  - by Eliasdx

  I want to program a HTTP WebChat using long-held HTTP requests (Comet), ajax and websockets (depending on the browser used). Userdatabase is in mysql. Chat is written in PHP except maybe the chat stream itself which could also be written in javascript (node.js): I don't want to start a php process per user as there is no good way to send the chat messages between these php childs. So I thought about writing an own socket server in either PHP or node.js which should be able to handle more then 1000 connections (chat users). As a purely web developer (php) I'm not much familiar with sockets as I usually let web server care about connections. The chat messages won't be saved on disk nor in mysql but in RAM as an array or object for best speed. As far as I know there is no way to handle multiple connections at the same time in a single php process (socket server), however you can accept a great amount of socket connections and process them successive in a loop (read and write; incoming message - write to all socket connections). The problem is that there will most-likely be a lag with ~1000 users and mysql operations could slow the whole thing down which will then affect all users. My question is: Can node.js handle a socket server with better performance? Node.js is event-based but I'm not sure if it can process multiple events at the same time (wouldn't that need multi-threading?) or if there is just an event queue. With an event queue it would be just like php: process user after user. I could also spawn a php process per chat room (much less users) but afaik there are singlethreaded IRC servers which are also capable to handle thousands of users. (written in c++ or whatever) so maybe it's also possible in php. I would prefer PHP over Node.js because then the project would be php-only and not a mixture of programming languages. However if Node can process connections simultaneously I'd probably choose it.

  Read the article

< Previous Page | 122 123 124 125 126 127 128 129 130 131 132 133  | Next Page >