Search Results

Search found 49224 results on 1969 pages for 'database mirroring sql se'.

Page 406/1969 | < Previous Page | 402 403 404 405 406 407 408 409 410 411 412 413  | Next Page >

• Storing statistics of multple data types in SQL Server 2008

  - by Mike

  I am creating a statistics module in SQL Server 2008 that allows users to save data in any number of formats (date, int, decimal, percent, etc...). Currently I am using a single table to store these values as type varchar, with an extra field to denote the datatype that it should be. When I display the value, I use that datatype field to format it. I use sprocs to calculate the data for reporting; and the datatype field to convert to the appropriate datatype for the appropriate calculations. This approach works, but I don't like storing all kinds of data in a varchar field. The only alternative that I can see is to have separate tables for each datatype I want to store, and save the record information to the appropriate table based on datatype. To retreive, I run a case statement to join the appropriate table and get the data. This seems to solve. This however, seems like a lot of work for ... what gain? Wondering if I'm missing something here. Is there a better way to do this? Thanks in advance!

  Read the article

• Cannot add table to context - LINQ-To-SQL

  - by Oskar Kjellin

  Hey, I'd be happy to give you more info if you need, just ask for it. I have in my database a table of articles, a table of tags and a link table. The article table has values like Id, Subject etc etc, the tags only have Id and Tag. The link has TagId and ArticleId. The problem is that when I drag drop the link-table nothing happens! This all worked before I decided to rename my column in the tables from "ID" to "Id" to correct spelling. Thanks in advance!

  Read the article

• Table design issues - should I create separate fields or store as a blob

  - by Ali

  Hi guys I'm working on my web based ordering system and we would like to maintain a kind of task history for each of our orders. A hsitory in the sense that we would like to maintain a log of who did what on an order like lets say an order has been entered - we would like to know if the order was acknowledged for an example. Or lets say somebody followed up on the order - etc. Consider that there are numerous situations like this for each order would it be wise to create a schema on the lines of: Orders ID - title - description - date - is_ack - is_follow - ack_by ..... That accounts to a lot of fields - on teh other hand I could have one LongText field called 'history' and fill it with a serialised object holding all the information. However in the latter case I can't run a query to lets say retrieve all orders that have not been acknowledged and stuff like that. With time requirements woudl change and I would be required to modify it to allow for more detailed tracking and that is why I need to set up a way which would be feasible to scale upon yet I don't want to be restricted on the SQL side too much.

  Read the article

• SQL Server insert with XML parameter - empty string not converting to null for numeric

  - by Mayo

  I have a stored procedure that takes an XML parameter and inserts the "Entity" nodes as records into a table. This works fine unless one of the numeric fields has a value of empty string in the XML. Then it throws an "error converting data type nvarchar to numeric" error. Is there a way for me to tell SQL to convert empty string to null for those numeric fields in the code below? -- @importData XML <- stored procedure param DECLARE @l_index INT EXECUTE sp_xml_preparedocument @l_index OUTPUT, @importData INSERT INTO dbo.myTable ( [field1] ,[field2] ,[field3] ) SELECT [field1] ,[field2] ,[field3] FROM OPENXML(@l_index, 'Entities/Entity', 1) WITH ( field1 int 'field1' ,field2 varchar(40) 'field2' ,field3 decimal(15, 2) 'field3' ) EXECUTE sp_xml_removedocument @l_index EDIT: And if it helps, sample XML. Error is thrown unless I comment out field3 in the code above or provide a value in field3 below. <?xml version="1.0" encoding="utf-16"?> <Entities> <Entity> <field1>2435</field1> <field2>843257-3242</field2> <field3 /> </Entity> </Entities>

  Read the article

• Linq to SQl over WCF Timesout after several calls

  - by Redeemed1

  I have a L2S Repository class which instantiates the L2S DataContext in its constructor. The repository is instantiated at run time (using Unity) in a service hosted in IIS with WCF. When I run up the client MVC applicaton the calls to the backend WCF service work for a while and then timeout. I suspected perhaps a database issue as I was depending on IIS garbage collection to dispose of unused DataContext instances in the IIS host but when I checked the characteristics of the problem I notice the following: The client makes the call to WCF but the WCF service does not respond. Next, the client times out Some time later (several minutes) the service actually executes the request by instantiating the repository and servicing the call. I have checked both client and server traces logs and only the client shows WCF errors (the timeout error). Where should I look? Is it something in WCF or is L2S possibly blocking with unfreed conenctions, resources etc.? Many thanks Brian

  Read the article

• noSQL/SQL/RoR: Trying to build scalable ratings table for the game

  - by alexeypro

  I am trying to solve complex thing (as it looks to me). I have next entities: PLAYER (few of them, with names like "John", "Peter", etc.). Each has unique ID. For simplicity let's think it's their name. GAME (few of them, say named "Hide and Seek", "Jump and Run", etc.). Same - each has unique ID. For simplicity of the case let it be it's name for now. SCORE (it's numeric). So, how it works. Each PLAYER can play in multiple GAMES. He gets some SCORE in every GAME. I need to build rating table -- and not one! Table #1: most played GAMES Table #2: best PLAYERS in all games (say the total SCORE in every GAME). Table #3: best PLAYERS per GAME (by SCORE in particularly that GAME). I could be build something straight right away, but that will not work. I will have more than 10,000 players; and 15 games, which will grow for sure. Score can be as low as 0, and as high as 1,000,000 (not sure if higher is possible at this moment) for player in the game. So I really need some relative data. Any suggestions? I am planning to do it with SQL, but may be just using it for key-value storage; anything -- any ideas are welcome. Thank you!

  Read the article

• SQL SERVER 2008 JOIN hints

  - by Nai

  Hi all, Recently, I was trying to optimise this query UPDATE Analytics SET UserID = x.UserID FROM Analytics z INNER JOIN UserDetail x ON x.UserGUID = z.UserGUID Estimated execution plan show 57% on the Table Update and 40% on a Hash Match (Aggregate). I did some snooping around and came across the topic of JOIN hints. So I added a LOOP hint to my inner join and WA-ZHAM! The new execution plan shows 38% on the Table Update and 58% on an Index Seek. So I was about to start applying LOOP hints to all my queries until prudence got the better of me. After some googling, I realised that JOIN hints are not very well covered in BOL. Therefore... Can someone please tell me why applying LOOP hints to all my queries is a bad idea. I read somewhere that a LOOP JOIN is default JOIN method for query optimiser but couldn't verify the validity of the statement? When are JOIN hints used? When the sh*t hits the fan and ghost busters ain't in town? What's the difference between LOOP, HASH and MERGE hints? BOL states that MERGE seems to be the slowest but what is the application of each hint? Thanks for your time and help people! I'm running SQL Server 2008 BTW. The statistics mentioned above are ESTIMATED execution plans.

  Read the article

• SQL Compact allow only one WCF Client

  - by Andreas Hoffmann

  Hi, I write a little Chat Application. To save some infos like Username and Password I store the Data in an SQL-Compact 3.5 SP1 Database. Everything working fine, but If another (the same .exe on the same machine) Client want to access the Service. It came an EndpointNotFound exception, from the ServiceReference.Class.Open() at the Second Client. So i remove the CE Data Access Code and I get no Error (with an if (false)) Where is the Problem? I googled for this, but no one seems the same error I get :( SOLUTION I used the wrapper in http://csharponphone.blogspot.com/2007/01/keeping-sqlceconnection-open-and-thread.html for threat safty, and now it works :) Client Code: public test() { var newCompositeType = new Client.ServiceReference1.CompositeType(); newCompositeType.StringValue = "Hallo" + DateTime.Now.ToLongTimeString(); newCompositeType.Save = (Console.ReadKey().Key == ConsoleKey.J); ServiceReference1.Service1Client sc = new Client.ServiceReference1.Service1Client(); sc.Open(); Console.WriteLine("Save " + newCompositeType.StringValue); sc.GetDataUsingDataContract(newCompositeType); sc.Close(); } Server Code public CompositeType GetDataUsingDataContract(CompositeType composite) { if (composite.Save) { SqlCeConnection con = new SqlCeConnection(Properties.Settings.Default.Con); con.Open(); var com = con.CreateCommand(); com.CommandText = "SELECT * FROM TEST"; SqlCeResultSet result = com.ExecuteResultSet(ResultSetOptions.Scrollable | ResultSetOptions.Updatable); var rec = result.CreateRecord(); rec["TextField"] = composite.StringValue; result.Insert(rec); result.Close(); result.Dispose(); com.Dispose(); con.Close(); con.Dispose(); } return composite; }

  Read the article

• How do I specify table data only for the current user's ID (VWD asp.net 3.5) ?

  - by Greg McNulty

  I'm using the Details View control of VWD asp.net 2008 I have a users database table and one of the columns contain the "unique" user's profile ID, created by VWD from the automatic profiles table. From my table, I would like to select only the data pertaining to the logged in user. How do I get the current unique user profileID and then have that used for the query? What I have so far: In the configure data source option of the control I select the columns I would like to display, select the check box for "Return Only Unique IDs" and the WHERE option. In this new window I select the Column to the profile userID ... "=" and then assumed I should select Source: "Profile". Now what should the parameter properties or value be to select only the logged userID specific data of the table? Any help is appreciated. Thank You!

  Read the article

• Dynamic where clause using Linq to SQL in a join query in a MVC application

  - by jhoefnagels

  Dear .Net Linq experts, I am looking for a way to query for products in a catalog using filters on properties which have been assigned to the product based on the category to which the product belongs. So I have the following entities involved: Products -Id -CategoryId Categories [Id] Properties [Id, CategoryId] PropertyValues [Id, PropertyId] ProductProperties [ProductId, PropertyValueId] When I ad a product to the catalog, multiple ProductProperties will be added based on the category and I would like to be able to filter all products from a category by selecting values for one or more properties. I will gather all filters, which I will hold in a list, by reading the URL. Now it is time to actually get the products based on multiple properties and I have been trying to find the right strategy but untill now it does not really work. Is there a way to make this work without writing SQL? I was trying something like this: productsInCategory = ProductRepository.Where(p => p.Category.Name == category); foreach (PropertyFilter pf in filterList) { productsInCategory = (from product in productsInCategory join pp in ProductPropertyRepository on product.Id equals pp.ProductId where pp.PropertyValueId == pf.ValueId select product); }

  Read the article

• Automatic Adjusting Range Table

  - by Bradford

  I have a table with a start date range, an end date range, and a few other additional columns. On input of a new record, I want to automatically adjust any overlapping date ranges (shrinking them to allow for the new input). I also want to ensure that no overlapping records can accidentally be inserted into this table. I'm using Oracle and Java for my application code. How should I enforce the prevention of overlapping date ranges and also allow for automatically adjusting overlapping ranges? Should I create an AFTER INSERT trigger, with a dbms_lock to serialize access, to prevent the overlapping data. Then in Java, apply the logic to auto adjust everything? Or should that part be in PL/SQL in stored procedure call? This is something that we need for a couple other tables so it'd be nice to abstract. If anyone has something like this already written, please share :) I did find this reference: http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:474221407101 Here's an example of how each of the 4 overlapping cases should be handled for adjustment on insert: = Example 1 = In DB (Start, End, Value): (0, 10, 'X') **(30, 100, 'Z') (200, 500, 'Y') Input (20, 50, 'A') Gives (0, 10, 'X') **(20, 50, 'A') **(51, 100, 'Z') (200, 500, 'Y') = Example 2 = In DB (Start, End, Value): (0, 10, 'X') **(30, 100, 'Z') (200, 500, 'Y') Input (40, 80, 'A') Gives (0, 10, 'X') **(30, 39, 'Z') **(40, 80, 'A') **(81, 100, 'Z') (200, 500, 'Y') = Example 3 = In DB (Start, End, Value): (0, 10, 'X') **(30, 100, 'Z') (200, 500, 'Y') Input (50, 120, 'A') Gives (0, 10, 'X') **(30, 49, 'Z') **(50, 120, 'A') (200, 500, 'Y') = Example 4 = In DB (Start, End, Value): (0, 10, 'X') **(30, 100, 'Z') (200, 500, 'Y') Input (20, 120, 'A') Gives (0, 10, 'X') **(20, 120, 'A') (200, 500, 'Y') The algorithm is as follows: given range = g; input range = i; output range set = o if i.start <= g.start if i.end >= g.end o_1 = i else o_1 = i o_2 = (o.end + 1, g.end) else if i.end >= g.end o_1 = (g.start, i.start - 1) o_2 = i else o_1 = (g.start, i.start - 1) o_2 = i o_3 = (i.end + 1, i.end)

  Read the article

• Linq to sql DataContext cannot set load options after results been returned

  - by David Liddle

  I have two tables A and B with a one-to-many relationship respectively. On some pages I would like to get a list of A objects only. On other pages I would like to load A with objects in B attached. This can be handled by setting the load options DataLoadOptions options = new DataLoadOptions(); options.LoadWith<A>(a => a.B); dataContext.LoadOptions = options; The trouble occurs when I first of all view all A's with load options, then go to edit a single A (do not use load options), and after edit return to the previous page. I understand why the error is occurring but not sure how to best get round this problem. I would like the DataContext to be loaded up per request. I thought I was achieving this by using StructureMap to load up my DataContext on a per request basis. This is all part of an n-tier application where my Controllers call Services which in turn call Repositories. ForRequestedType<MyDataContext>() .CacheBy(InstanceScope.PerRequest) .TheDefault.Is.Object(new MyDataContext()); ForRequestedType<IAService>() .TheDefault.Is.OfConcreteType<AService>(); ForRequestedType<IARepository>() .TheDefault.Is.OfConcreteType<ARepository>(); Here is a brief outline of my Repository public class ARepository : IARepository { private MyDataContext db; public ARepository(MyDataContext context) { db = context; } public void SetLoadOptions(DataLoadOptions options) { db.LoadOptions = options; } public IQueryable<A> Get() { return from a in db.A select a; } So my ServiceLayer, on View All, sets the load options and then gets all A's. On editing A my ServiceLayer should spin up a new DataContext and just fetch a list of A's. When sql profiling, I can see that when I go to the Edit page it is requesting A with B objects.

  Read the article

• SQL - Converting 24-hour ("military") time (2145) to "AM/PM time" (9:45 pm)

  - by CheeseConQueso

  I have 2 fields I'm working with that are stored as smallint military structured times. Edit I'm running on IBM Informix Dynamic Server Version 10.00.FC9 beg_tm and end_tm Sample values beg_tm 545 end_tm 815 beg_tm 1245 end_tm 1330 Sample output beg_tm 5:45 am end_tm 8:15 am beg_tm 12:45 pm end_tm 1:30 pm I had this working in Perl, but I'm looking for a way to do it with SQL and case statements. Is this even possible? EDIT Essentially, this formatting has to be used in an ACE report. I couldn't find a way to format it within the output section using simple blocks of if(beg_tm>=1300) then beg_tm = vbeg_tm - 1200 Where vbeg_tm is a declared char(4) variable EDIT This works for hours =1300 (EXCEPT FOR 2230 !!) select substr((beg_tm-1200),0,1)||":"||substr((beg_tm-1200),2,2) from mtg_rec where beg_tm>=1300; This works for hours < 1200 (sometimes.... 10:40 is failing) select substr((mtg_rec.beg_tm),0,(length(cast(beg_tm as varchar(4)))-2))||":"||(substr((mtg_rec.beg_tm),2,2))||" am" beg_tm from mtg_rec where mtg_no = 1; EDIT Variation of casting syntax used in Jonathan Leffler's expression approach SELECT beg_tm, cast((MOD(beg_tm/100 + 11, 12) + 1) as VARCHAR(2)) || ':' || SUBSTRING(cast((MOD(beg_tm, 100) + 100) as CHAR(3)) FROM 2) || SUBSTRING(' am pm' FROM (MOD(cast((beg_tm/1200) as INT), 2) * 3) + 1 FOR 3), end_tm, cast((MOD(end_tm/100 + 11, 12) + 1) as VARCHAR(2)) || ':' || SUBSTRING(cast((MOD(end_tm, 100) + 100) as CHAR(3)) FROM 2) || SUBSTRING(' am pm' FROM (MOD(cast((end_tm/1200) as INT), 2) * 3) + 1 FOR 3) FROM mtg_rec where mtg_no = 39;

  Read the article

• Using SQL to calculate a date within a certain date range

  - by David Passmore

  Hi, I'm using access 2007 and i am trying to set up a database to act as a library system, i need a function that automatically calculates a date 14 days after a given date i.e. Loan Date vs. Due Date. But the library is open only on certain Days. So i need the 14 days not to include the dates that are out of hours, like weekends and school holidays etc. I think i need to use Select Case or IIF's? Help would be appreciated! Thanks David

  Read the article

• Should i really use integer primary IDs?

  - by arthurprs

  For example, i always generate an auto-increment field for the users table, but i also specifies an UNIQUE index on their usernames. There is situations that i first need to get the userId for a given username and then execute the desired query. Or use a JOIN in the desired query. It's 2 trips to the database or a JOIN vs. a varchar index The above is just an example There is a real performance benefit on INT over small VARCHAR indexes? Thanks in advance!

  Read the article

• refactor LINQ TO SQL custom properties that instantiate datacontext

  - by Thiago Silva

  I am working on an existing ASP.NET MVC app that started small and has grown with time to require a good re-architecture and refactoring. One thing that I am struggling with is that we've got partial classes of the L2S entities so we could add some extra properties, but these props create a new data context and query the DB for a subset of data. This would be the equivalent to doing the following in SQL, which is not a very good way to write this query as oppsed to joins: SELECT tbl1.stuff, (SELECT nestedValue FROM tbl2 WHERE tbl2.Foo = tbl1.Bar), tbl1.moreStuff FROM tbl1 so in short here's what we've got in some of our partial entity classes: public partial class Ticket { public StatusUpdate LastStatusUpdate { get { //this static method call returns a new DataContext but needs to be refactored var ctx = OurDataContext.GetContext(); var su = Compiled_Query_GetLastUpdate(ctx, this.TicketId); return su; } } } We've got some functions that create a compiled query, but the issue is that we also have some DataLoadOptions defined in the DataContext, and because we instantiate a new datacontext for getting these nested property, we get an exception "Compiled Queries across DataContexts with different LoadOptions not supported" . The first DataContext is coming from a DataContextFactory that we implemented with the refactorings, but this second one is just hanging off the entity property getter. We're implementing the Repository pattern in the refactoring process, so we must stop doing stuff like the above. Does anyone know of a good way to address this issue?

  Read the article

• LINQ to SQL join when there aren't results

  - by Boarder2

  Given the following database structure I'm trying to write a LINQ query that will return images grouped by tags it's associated with. So far I've got this: var images = from img in db.Images join imgTags in db.ImageTags on img.idImage equals imgTags.idImage join t in db.Tags on imgTags.idTag equals t.idTag where img.OCRData.Contains(searchText.Text) group img by new { t.TagName } into aGroup select new { GroupName = aGroup.Key.TagName, Items = from x in aGroup select new ImageFragment() { ImageID = x.idImage, ScanDate = x.ScanTime } }; Which works great. However, I also want to return Images that do not have any tags associated with them in a group of "(Untagged)" or something. I can't wrap my head around how I would do this without inserting a default tag for every image and that seems like generally not a very good solution.

  Read the article

• LINQ-To-SQL and Mapping Table Deletions

  - by Jake

  I have a many-to-many relationship between two tables, let's say Friends and Foods. If a friend likes a food I stick a row into the FriendsFoods table, like this: ID Friend Food 1 'Tom' 'Pizza' FriendsFoods has a Primary Key 'ID', and two non-null foreign keys 'Friend' and 'Food' to the 'Friends' and 'Foods' tables, respectively. Now suppose I have a Friend tom .NET object corresponding to 'Tom', and Tom no longer likes pizza (what is wrong with him?) FriendsFoods ff = tblFriendsFoods.Where(x => x.Friend.Name == 'Tom' && x.Food.Name == 'Pizza').Single(); tom.FriendsFoods.Remove(ff); pizza.FriendsFoods.Remove(ff); If I try to SubmitChanges() on the DataContext, I get an exception because it attempts to insert a null into the Friend and Food columns in the FriendsFoods table. I'm sure I can put together some kind of convoluted logic to track changes to the FriendsFoods table, intercept SubmitChanges() calls, etc to try and get this to work the way I want, but is there a nice, clean way to remove a Many-To-Many relationship with LINQ-To-SQL?

  Read the article

• Backup & recovery of multiple MySQL databases (InnoDB & MyISAM)

  - by Cymon

  I am working on nightly and hourly backups of MySQL Databases. There are multiple MySQL databases which are either InnoDB or MyISAM (Note: Each database is either InnoDB or MyISAM for a reason). With the 2 different types I want to make sure I am grabbing everything that is needed for backup and recovery. Here is my current plan Nightly -mysqldump of each DB which is stored locally and remotely. Hourly -flush binary logs and store them locally and remotely. Weekly -expire binary logs older than a week. I feel like I am grabbing everything that is needed for the MyISAM databases but I am concerned about the InnoDB databases and the log files (ib_logfile0, ib_logfile1, ibdata1) they create. Should I backup these files? Nightly? Hourly? Both? Do I really need them if I am already doing the above nightly and hourly backups?

  Read the article

• Wondering how Facebook does the "Mutual friends" feature

  - by Pierre

  Hello, I'm currently developing an application to allow students to manage their courses, and I don't really know how to design the database for a specific feature. The client wants, a lot like Facebook, that when a student displays the list of people currently in a specific course, the people with the most mutual courses are displayed first. As an additional feature, I would like to add a search feature to allow students to search for another one, and displaying first in the search results the people with most mutual courses. I currently use MySQL, I plan to use Cassandra for some other features, and I also use Memcached for result caching. Thanks.

  Read the article

• Fraud Detection with the SQL Server Suite Part 1

  - by Dejan Sarka

  While working on different fraud detection projects, I developed my own approach to the solution for this problem. In my PASS Summit 2013 session I am introducing this approach. I also wrote a whitepaper on the same topic, which was generously reviewed by my friend Matija Lah. In order to spread this knowledge faster, I am starting a series of blog posts which will at the end make the whole whitepaper. Abstract With the massive usage of credit cards and web applications for banking and payment processing, the number of fraudulent transactions is growing rapidly and on a global scale. Several fraud detection algorithms are available within a variety of different products. In this paper, we focus on using the Microsoft SQL Server suite for this purpose. In addition, we will explain our original approach to solving the problem by introducing a continuous learning procedure. Our preferred type of service is mentoring; it allows us to perform the work and consulting together with transferring the knowledge onto the customer, thus making it possible for a customer to continue to learn independently. This paper is based on practical experience with different projects covering online banking and credit card usage. Introduction A fraud is a criminal or deceptive activity with the intention of achieving financial or some other gain. Fraud can appear in multiple business areas. You can find a detailed overview of the business domains where fraud can take place in Sahin Y., & Duman E. (2011), Detecting Credit Card Fraud by Decision Trees and Support Vector Machines, Proceedings of the International MultiConference of Engineers and Computer Scientists 2011 Vol 1. Hong Kong: IMECS. Dealing with frauds includes fraud prevention and fraud detection. Fraud prevention is a proactive mechanism, which tries to disable frauds by using previous knowledge. Fraud detection is a reactive mechanism with the goal of detecting suspicious behavior when a fraudster surpasses the fraud prevention mechanism. A fraud detection mechanism checks every transaction and assigns a weight in terms of probability between 0 and 1 that represents a score for evaluating whether a transaction is fraudulent or not. A fraud detection mechanism cannot detect frauds with a probability of 100%; therefore, manual transaction checking must also be available. With fraud detection, this manual part can focus on the most suspicious transactions. This way, an unchanged number of supervisors can detect significantly more frauds than could be achieved with traditional methods of selecting which transactions to check, for example with random sampling. There are two principal data mining techniques available both in general data mining as well as in specific fraud detection techniques: supervised or directed and unsupervised or undirected. Supervised techniques or data mining models use previous knowledge. Typically, existing transactions are marked with a flag denoting whether a particular transaction is fraudulent or not. Customers at some point in time do report frauds, and the transactional system should be capable of accepting such a flag. Supervised data mining algorithms try to explain the value of this flag by using different input variables. When the patterns and rules that lead to frauds are learned through the model training process, they can be used for prediction of the fraud flag on new incoming transactions. Unsupervised techniques analyze data without prior knowledge, without the fraud flag; they try to find transactions which do not resemble other transactions, i.e. outliers. In both cases, there should be more frauds in the data set selected for checking by using the data mining knowledge compared to selecting the data set with simpler methods; this is known as the lift of a model. Typically, we compare the lift with random sampling. The supervised methods typically give a much better lift than the unsupervised ones. However, we must use the unsupervised ones when we do not have any previous knowledge. Furthermore, unsupervised methods are useful for controlling whether the supervised models are still efficient. Accuracy of the predictions drops over time. Patterns of credit card usage, for example, change over time. In addition, fraudsters continuously learn as well. Therefore, it is important to check the efficiency of the predictive models with the undirected ones. When the difference between the lift of the supervised models and the lift of the unsupervised models drops, it is time to refine the supervised models. However, the unsupervised models can become obsolete as well. It is also important to measure the overall efficiency of both, supervised and unsupervised models, over time. We can compare the number of predicted frauds with the total number of frauds that include predicted and reported occurrences. For measuring behavior across time, specific analytical databases called data warehouses (DW) and on-line analytical processing (OLAP) systems can be employed. By controlling the supervised models with unsupervised ones and by using an OLAP system or DW reports to control both, a continuous learning infrastructure can be established. There are many difficulties in developing a fraud detection system. As has already been mentioned, fraudsters continuously learn, and the patterns change. The exchange of experiences and ideas can be very limited due to privacy concerns. In addition, both data sets and results might be censored, as the companies generally do not want to publically expose actual fraudulent behaviors. Therefore it can be quite difficult if not impossible to cross-evaluate the models using data from different companies and different business areas. This fact stresses the importance of continuous learning even more. Finally, the number of frauds in the total number of transactions is small, typically much less than 1% of transactions is fraudulent. Some predictive data mining algorithms do not give good results when the target state is represented with a very low frequency. Data preparation techniques like oversampling and undersampling can help overcome the shortcomings of many algorithms. SQL Server suite includes all of the software required to create, deploy any maintain a fraud detection infrastructure. The Database Engine is the relational database management system (RDBMS), which supports all activity needed for data preparation and for data warehouses. SQL Server Analysis Services (SSAS) supports OLAP and data mining (in version 2012, you need to install SSAS in multidimensional and data mining mode; this was the only mode in previous versions of SSAS, while SSAS 2012 also supports the tabular mode, which does not include data mining). Additional products from the suite can be useful as well. SQL Server Integration Services (SSIS) is a tool for developing extract transform–load (ETL) applications. SSIS is typically used for loading a DW, and in addition, it can use SSAS data mining models for building intelligent data flows. SQL Server Reporting Services (SSRS) is useful for presenting the results in a variety of reports. Data Quality Services (DQS) mitigate the occasional data cleansing process by maintaining a knowledge base. Master Data Services is an application that helps companies maintaining a central, authoritative source of their master data, i.e. the most important data to any organization. For an overview of the SQL Server business intelligence (BI) part of the suite that includes Database Engine, SSAS and SSRS, please refer to Veerman E., Lachev T., & Sarka D. (2009). MCTS Self-Paced Training Kit (Exam 70-448): Microsoft® SQL Server® 2008 Business Intelligence Development and Maintenance. MS Press. For an overview of the enterprise information management (EIM) part that includes SSIS, DQS and MDS, please refer to Sarka D., Lah M., & Jerkic G. (2012). Training Kit (Exam 70-463): Implementing a Data Warehouse with Microsoft® SQL Server® 2012. O'Reilly. For details about SSAS data mining, please refer to MacLennan J., Tang Z., & Crivat B. (2009). Data Mining with Microsoft SQL Server 2008. Wiley. SQL Server Data Mining Add-ins for Office, a free download for Office versions 2007, 2010 and 2013, bring the power of data mining to Excel, enabling advanced analytics in Excel. Together with PowerPivot for Excel, which is also freely downloadable and can be used in Excel 2010, is already included in Excel 2013. It brings OLAP functionalities directly into Excel, making it possible for an advanced analyst to build a complete learning infrastructure using a familiar tool. This way, many more people, including employees in subsidiaries, can contribute to the learning process by examining local transactions and quickly identifying new patterns.

  Read the article

• structured vs. unstructured data in db

  - by Igor

  the question is one of design. i'm gathering a big chunk of performance data with lots of key-value pairs. pretty much everything in /proc/cpuinfo, /proc/meminfo/, /proc/loadavg, plus a bunch of other stuff, from several hundred hosts. right now, i just need to display the latest chunk of data in my UI. i will probably end up doing some analysis of the data gathered to figure out performance problems down the road, but this is a new application so i'm not sure what exactly i'm looking for performance-wise just yet. i could structure the data in the db -- have a column for each key i'm gathering. the table would end up being O(100) columns wide, it would be a pain to put into the db, i would have to add new columns if i start gathering a new stat. but it would be easy to sort/analyze the data just using SQL. or i could just dump my unstructured data blob into the table. maybe three columns -- host id, timestamp, and a serialized version of my array, probably using JSON in a TEXT field. which should I do? am i going to be sorry if i go with the unstructured approach? when doing analysis, should i just convert the fields i'm interested in and create a new, more structured table? what are the trade-offs i'm missing here?

  Read the article

• SQL deadlock on delete then bulk insert

  - by StarLite

  I have an issue with a deadlock in SQL Server that I haven't been able to resolve. Basically I have a large number of concurrent connections (from many machines) that are executing transactions where they first delete a range of entries and then re-insert entries within the same range with a bulk insert. Essentially, the transaction looks like this BEGIN TRANSACTION T1 DELETE FROM [TableName] WITH( XLOCK HOLDLOCK ) WHERE [Id]=@Id AND [SubId]=@SubId INSERT BULK [TableName] ( [Id] Int , [SubId] Int , [Text] VarChar(max) COLLATE SQL_Latin1_General_CP1_CI_AS ) WITH(CHECK_CONSTRAINTS, FIRE_TRIGGERS) COMMIT TRANSACTION T1 The bulk insert only inserts items matching the Id and SubId of the deletion in the same transaction. Furthermore, these Id and SubId entries should never overlap. When I have enough concurrent transaction of this form, I start to see a significant number of deadlocks between these statements. I added the locking hints XLOCK HOLDLOCK to attempt to deal with the issue, but they don't seem to be helpling. The canonical deadlock graph for this error shows: Connection 1: Holds RangeX-X on PK_TableName Holds IX Page lock on the table Requesting X Page lock on the table Connection 2: Holds IX Page lock on the table Requests RangeX-X lock on the table What do I need to do in order to ensure that these deadlocks don't occur. I have been doing some reading on the RangeX-X locks and I'm not sure I fully understand what is going on with these. Do I have any options short of locking the entire table here?

  Read the article

• Manage Foreign key and Drop downlist for optional field in .NET

  - by Brij

  What is the best way to handle following situation? A dropdown(for master table) is optional in a particular form. But, In database table the field is constrained with foreign key. If user don't select from dropdown then It creates problem because of foreign key. One solution is to create default option in master table and use it in case of blank selection. but in dropdown, we need to handle this to show on top. Is it perfect solution? Is there any other optimized solution for this? Thanks

  Read the article

• How to combine specific column values in an SQL statement

  - by Mehper C. Palavuzlar

  There are two variables in our database called OB and B2B_OB. There are EP codes and each EP may have one of the following 4 combinations: EP OB B2B_OB --- -- ------ 3 X 7 X 11 14 X X What I want to do is to combine the X's in the fetched list so that I can have A or B value for a single EP. My conditions are: IF (OB IS NULL AND B2B_OB IS NULL) THEN TYPE = A IF (OB IS NOT NULL OR B2B_OB IS NOT NULL) THEN TYPE = B The list I want to fetch is like this one: EP TYPE --- ---- 3 B 7 B 11 A 14 B How can I do this in my query? TIA.

  Read the article

< Previous Page | 402 403 404 405 406 407 408 409 410 411 412 413  | Next Page >