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  • Can Goldberg algorithm in ocamlgraph be used to find Minimum Cost Flow graph?

    - by Tautrimas
    I'm looking for an implementation to the Minimum Cost Flow graph problem in OCaml. OCaml library ocamlgraph has Goldberg algorithm implementation. The paper called Efficient implementation of the Goldberg-Tarjan minimum-cost flow algorithm is noting that Goldberg-Tarjan algorithm can find minimum cost graph. Question is, does ocamlgraph algorithm also find the minimum cost? Library documentation only states, that it's suitable at least for the maximum flow problem. If not, does anybody have a good link to a nice any minimum cost optimization algorithm code? I will manually translate it into OCaml then. Forgive me, if I missed it on Wikipedia: there are too many algos on flow networks for the first day!

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  • How to save in Hindi in database using MVC application

    - by user219315
    I have a MVC application and using the entity framework model for MYSQL database. I what to save hindi text in database. When I using the hindi text then it is showing ?? in database. I am using ckeditor to enter the text How can I save the hindi text.I have also changed the collation to utf-8. Thanks supriya

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  • How do I force a restore over an existing database?

    - by Ian Boyd
    I have a database, and i want to force a restore over top of it. I check the option: Overwrite the existing database (WITH REPLACE) But, as expected, SSMS is unable to overwrite the existing database. Of course i don't want different filenames; i want to overwrite the existing database. How do i force a restore over an existing database? And for Google search crawler: File '%s' is claimed by '%s'(4) and '%s"(3). The WITH MOVE clause can be used to relocate one or more files. RESTORE DATABASE is terminating abnormally. (Microsoft SQL Server, Error: 3176) Update The script (before i deleted the database, because i needed to get it done) was: RESTORE DATABASE [HealthCareGovManager] FILE = N'HealthCareGovManager_Data', FILE = N'HealthCareGovManager_Archive', FILE = N'HealthCareGovManager_AuditLog' FROM DISK = N'D:\STAGING\HealthCareGovManager10232013.bak' WITH FILE = 1, MOVE N'HealthCareGovManager_Data' TO N'D:\CGI Data\HealthCareGovManager.MDF', MOVE N'HealthCareGovManager_Archive' TO N'D:\CGI Data\HealthCareGovManager.ndf', MOVE N'HealthCareGovManager_AuditLog' TO N'D:\CGI Data\HealthCareGovManager.ndf', MOVE N'HealthCareGovManager_Log' TO N'D:\CGI Data\HealthCareGovManager.LDF', NOUNLOAD, REPLACE, STATS = 10 I used the UI to delete the existing database, so that i could use the UI to force an overwrite of the (non)existing database. Hopefully there can be an answer so that the next guy can have an answer. No, nobody was in the context of the database (The error message from other connections is quite different from this error, and i only got to see this error after i killed the other connections).

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  • Copying metadata over a database link in Oracle 10g

    - by Tunde
    Thanks in advance for your help experts. I want to be able to copy over database objects from database A into database B with a procedure created on database B. I created a database link between the two and have tweaked the get_ddl function of the dbms_metadata to look like this: create or replace function GetDDL ( p_name in MetaDataPkg.t_string p_type in MetaDataPkg.t_string ) return MetaDataPkg.t_longstring is -- clob v_clob clob; -- array of long strings c_SYSPrefix constant char(4) := 'SYS_'; c_doublequote constant char(1) := '"'; v_longstrings metadatapkg.t_arraylongstring; v_schema metadatapkg.t_string; v_fullength pls_integer := 0; v_offset pls_integer := 0; v_length pls_integer := 0; begin SELECT DISTINCT OWNER INTO v_schema FROM all_objects@ENTORA where object_name = upper(p_name); -- get DDL v_clob := dbms_metadata.get_ddl(p_type, upper(p_name), upper(v_schema)); -- get CLOB length v_fullength := dbms_lob.GetLength(v_clob); for nIndex in 1..ceil(v_fullength / 32767) loop v_offset := v_length + 1; v_length := least(v_fullength - (nIndex - 1) * 32767, 32767); dbms_lob.read(v_clob, v_length, v_offset, v_longstrings(nIndex)); -- Remove table’s owner from DDL string: v_longstrings(nIndex) := replace( v_longstrings(nIndex), c_doublequote || user || c_doublequote || '.', '' ); -- Remove the following from DDL string: -- 1) "new line" characters (chr(10)) -- 2) leading and trailing spaces v_longstrings(nIndex) := ltrim(rtrim(replace(v_longstrings(nIndex), chr(10), ''))); end loop; -- close CLOB if (dbms_lob.isOpen(v_clob) > 0) then dbms_lob.close(v_clob); end if; return v_longstrings(1); end GetDDL; so as to remove the schema prefix that usually comes with metadata. I get a null value whenever I run this function over the database link with the following queries. select getddl( 'TABLE', 'TABLE1') from user_tables@ENTORA where table_name = 'TABLE1'; select getddl( 'TABLE', 'TABLE1') from dual@ENTORA; t_string is varchar2(30) t_longstring is varchar2(32767) and type t_ArrayLongString is table of t_longstring I would really appreciate it if any one could help. Many thanks.

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  • what does driver program mean?

    - by Tom
    there is a quote from Algorithms for Java (sedgwick 2003) p. 135: "we commonly use driver programs when developing or debugging adt iplementations" what is meant by driver program? google just gives me loads of info about programming drivers, clearly not related

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  • Android Content Provider database leak issue

    - by MattC
    I am writing a content provider for this application and in my content provider I am opening a database connection, running a query and returning the cursor of results to the calling program. If I close this database connection in the provider, the cursor has no results. If I leave it open, I get "leak found" errors in my DDMS log. What am I missing here? What's the clean, proper way to return a cursor of database results?

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  • Best practices for extending third party databases?

    - by Eric Watkins
    I have a situation where our developers extended a Third party database (MS SQL) by adding tables, views, stored procedures, and functions. Recently when the vender issued updates to the database they dropped all of our custom objects. The question now is what are some best practices that will allow us to extend the third party database but keep our objects safe from future updates? My first thought is to create a separate database but then I’m stuck with fully qualifying all the references back to the original database which may cause issues promoting database changes from test to production.

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  • Mutual Information / Entropy Calculation Help

    - by Fillip
    Hi, Hoping someone can give me some pointers with this entropy problem. Say X is chosen randomly from the uniform integer distribution 0-32 (inclusive). I calculate the entropy, H(X) = 32 bits, as each Xi has equal probability of occurring. Now, say the following pseudocode executes. int r = rand(0,1); // a random integer 0 or 1 r = r * 33 + X; How would I work out the mutual information between the two variables r and X? Mutual Information is defined as I(X; Y) = H(X) - H(X|Y) but I don't really understand how to apply the conditional entropy H(X|Y) to this problem. Thanks

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  • Best practices or tools for installing a MS SQL database

    - by Maestro1024
    Best practices or tools for installing a MS SQL database I have a MS SQL database designed with the MS SQL GUI database editor/Visual Studio. What is the best way to "install" that database on other systems. Said another way how should I ship this thing? I know I can save the scripts and set the primary/foreign keys with T-SQL but I suspect their is something better. I guess you could have people restore from backup but that does not seem very professional. What other choices are there and what are the pluses and minuses?

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  • UitableView Problem in deleating items from database

    - by Arun Sharma
    Hi All, I am using in UitableView database.My table view works successfully (add single item,add multiple item,delete all) only problem is there when i want to delete single item for this i using Uitableview edit option. so how i add database method for deleting single item from database and also from table view. Please help me.

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  • sqlite3 'database is locked' won't go away with retries

    - by Azarias
    I have a sqlite3 database that is accessed by a few threads (3-4). I am aware of the general limitations of sqlite3 with regards to concurrency as stated http://www.sqlite.org/faq.html#q6 , but I am convinced that is not the problem. All of the threads both read and write from this database. Whenever I do a write, I have the following construct: try: Cursor.execute(q, params) Connection.commit() except sqlite3.IntegrityError: Notify except sqlite3.OperationalError: print sys.exc_info() print("DATABASE LOCKED; sleeping for 3 seconds and trying again") time.sleep(3) Retry On some runs, I won't even hit this block, but when I do, it never comes out of it (keeps retrying, but I keep getting the 'database is locked' error from exc_info. If I understand the reader/writer lock usage correctly, some amount of waiting should help with the contention. What this sounds like is deadlock, but I do not use any transactions in my code, and every SELECT or INSERT is simply a one off. Some threads, however, keep the same connection when they do their operation (which includes a mix of SELECTS and INSERTS and other modifiers). I would appericiate it if you could shade a light on this, and also ways around fixing it (besides using a different database engine.)

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  • Subgraph isomorphism on disconnected graphs with connection rules

    - by Mac
    Hello I was wondering if anyone knows about a solution to the following problem: Given a graph g as query and a set of graphs B with connection rules R. The connection rules describe how two graphs out of B can be linked together. Linking points are marked vertexes. Find all combination of graphs in B that contain g as a subgraph. Regards Mac

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  • Find the shortest path in a graph which visits certain nodes.

    - by dmd
    I have a undirected graph with about 100 nodes and about 200 edges. One node is labelled 'start', one is 'end', and there's about a dozen labelled 'mustpass'. I need to find the shortest path through this graph that starts at 'start', ends at 'end', and passes through all of the 'mustpass' nodes (in any order). ( http://3e.org/local/maize-graph.png / http://3e.org/local/maize-graph.dot.txt is the graph in question - it represents a corn maze in Lancaster, PA)

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  • ASP.NET LINQ to SQL SubmitChanges() doesn't update the database

    - by Alex
    In my 2nd ASP.NET MVC project I'm facing a very weird problem: when I call the SubmitChanges method of the DataContext class, nothing updates in the database. It's weird because everything works fine with my first project. I'm using a remote database created in Sql Server Management Studio, I tried doing some queries there and in Visual Studio 2010 (where I have the connection to the database), they all work. Where might the problem be hidden?

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  • how to synchronize database table and directory with php

    - by twmulloy
    hello, I have a directory with files and a database table with what should be the same files. I would like to be able to synchronize the database table with the directory. What would be the most efficient way to do this? or would I realistically only be able to do this in a brute manner? Here's my approach: 1. retrieve all of the files in the directory as array 2. retrieve all of the filenames in the database table as array 3. loop through the file values in the directory array and use in_array() on the database table array to verify the filename is in that array, and if not then start building an array to insert the missing filenames. run db query to add each missing file row to database table 4. loop through directory array and use in_array() on the directory array and anything not found in the directory array will just be deleted from the table. Is there a better way to go about this? or something better for this in php than in_array()?

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  • a brand new FS based on a database without using fuse

    - by Devrim
    hi all, To serve millions of files out of a single directory, being able to connect to a drive from hundreds of endpoints, and for some other reasons (to avoid gluster/nfs/all fs based networking solutions), I want to evaluate the possibility of making a filesystem that's based on a mongodb (or any other). Basically, it works like fusefs, every single file is kept in mongo gridfs. In theory, I do, mount mongodbfs /mountPoint mongodb://localhost then when i say touch /mountPoint/test.txt this file is inserted into mongodb. This FS will also store uid/gid and perms with the file, we can throw hundreds of servers to it, and no useradd will be necessary. I'm not thinking to include all the features of FS, just the ones we need. My question is, how do I start my quest in finding resources, books, links, people, developers who'd help me implement this? at least a proof of concept. Is it feasible? What should I expect as a timeline for such undertaking? Please only think about gazillion small files and folders.

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  • UItableView Problem in deleting items from database

    - by Arun Sharma
    Hi All, I am using in UitableView database.My table view works successfully (add single item,add multiple item,delete all) only problem is there when i want to delete single item for this i using Uitableview edit option. so how i add database method for deleting single item from database and also from table view. Please help me.

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  • How to Shrink Transaction log in sql server database in replication

    - by Renju
    Hi I'm having a production database and its replicated report database. How to shrink the transaction log files in the production database as the log file size is increasing. I had tried DBCC SHRINKFILE and SHRINKDATABASE commands but it does not work for me. I can't detach and shrink and attach back as the db in replication. Please help me in this issue.

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  • C# Dynamic Query Without A Database Model

    - by hitopp
    I have been searching the web for a solution to dynamic queries. I have found many different solutions (e.g. Linq to Sql, Dynamic Linq Expressions, Dynamic Query), but all of these solutions involve some sort of previous knowledge of the database (like a model in code). Maybe what I am asking is way off the deep end, but is there any possible way to dynamically query a database without a model? For example, a database has a Customers table with the following columns: CustomerID Name FavoriteColor I want to create a query as SELECT Name FROM Customers WHERE @0 = @1, where the two placeholders are populated dynamically. The resulting data does not tie to a model class and I would prefer to use some sort of framework to build the queries, not simple string concatenation. The System.Linq.Dynamic namespace came really close to fulfilling this request, but it uses a database model. I realize this is crazy, but I was just curious.

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  • XCode copies blank database when doing build...

    - by Incognitii
    I've noticed that even though I placed my sqlite3 database in the "resources" folder, and even though I checked the "Copy file" box, when I do a build, XCode creates an empty database toi the application folder it's building...so it's FINDING the database, and OPENING it, but there's nothing IN it, so when I do a sqlite3_prepare_v2, I get a SQLITE_ERROR... Help! What am I doing wrong?

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  • Algorithm for Determining Variations of Differing Lengths

    - by joseph.ferris
    I have four objects - for the sake of arguments, let say that they are the following letters: A B C D I need to calculate the number of variations that can be made for these under the following two conditions: No repetition Objects are position agnostic Taking the above, this means that with a four object sequence, I can have only one sequence that matches the criteria (since order is not considered for being unique): ABCD There are four variations for a three object combination from the four object pool: ABC, ABD, ACD, and BCD There are six variations for a two object combination from the four object pool: AB, AC, AD, BC, BD, and CD And the most simple one, if taken on at a time: A, B, C, and D I swear that this was something covered in school, many, many years ago - and probably forgotten since I didn't think I would use it. :-) I am anticipating that factorials will come into play, but just trying to force an equation is not working. Any advice would be appreciated.

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  • What is the difference between causal models and directed graphical models?

    - by Neil G
    What is the difference between causal models and directed graphical models? or: What is the difference between causal relationships and directed probabilistic relationships? or, even better: What would you put in the interface of a DirectedProbabilisticModel class, and what in a CausalModel class? Would one inherit from the other? Collaborative solution: interface DirectedModel { map<Node, double> InferredProbabilities(map<Node, double> observed_probabilities, set<Node> nodes_of_interest) } interface CausalModel: DirectedModel { bool NodesDependent(set<Node> nodes, map<Node, double> context) map<Node, double> InferredProbabilities(map<Node, double> observed_probabilities, map<Node, double> externally_forced_probabilities, set<Node> nodes_of_interest) }

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