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  • Windows?????(C#?Visual Basic?Active Server Pages?Visual C++)??Oracle Database?????

    - by Yusuke.Yamamoto
    C#?Visual Basic?Active Server Pages?Visual C++???????? Windows ???????????????Oracle Database ????·???????????????? ???? Windows ?????????????Oracle Database ??????????·????·???????????? .NET Oracle Data Provider for .NET Oracle Provider for OLE DB ???? OLE DB.NET Oracle ODBC Driver ???? ODBC.NET Visual Basic/ASP/Access Oracle Objects for OLE(OO4O) Oracle ODBC Driver Oracle Provider for OLE DB OO4O?OLE DB?ODBC?ODP.NET ??Oracle Data Access Component(ODAC) ???????????? OTN Oracle Data Access Components ??????? ???? ????????Oracle DB????????????? Oracle on Windows / .NET ?? ?????????? .NET|???????????

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  • ??Oracle EBS R12 on Sun database Machine MAA&HPA ????

    - by longchun.zhu
    ??????1????,3??hands-on ?????, ?????????XXX,XXX Partners ??OSS,SC,??iTech ?20????,,??????????,?????????????!??????,????????????????????????! ??,??????,???????,???????,??EBS ???????,??,????ORACLE ?N?????????????,????????????? 5? ?????????, ?????????,????????2T??..??????????PPT ?????????!???eric.gao ??????????? ?????????, ????eric,cindy,??????????! ?????????! ?????,???????????,????,????????... Course Objectives ??: After completing this course, you can be able to do the following : •Understand EBS R12 on Exadata MAA •Install and Configure Oracle EBS R12 Single Instance •Apply Chinese Package on EBS R12 •Upgrade Application DB Version to 11gR2 •Deploy Clone EBS R12 to Sun Database Machine •Migration File System to Exadata Storage ASM •Converting Application DB to RAC •Configure EBS R12 MAA with Exadata 1: Oracle EBS R12.1.1 Single Instance Install 2: Apply Chinese Package on EBS R12 3: Upgrade Application DB Version to 11gR2 4: Clone EBS R12 to Sun Database Machine 5: Migrate File Systems to ASM Storage 6: Converting Application DB to RAC 7: Configure EBS MAA with Exadata

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  • ???????????????:????????????

    - by ???02
    ???????????????:??????????????????????????????????????????????????????????ID?????????????Oracle Identity Manager????????????????????Oracle Database Vault???????·?????Oracle Audit Vault????????????????·????????????????????????????????????????????·?????????·?????????????????????????????? ?????????????????????????(????????????????????)???·????????????????????? ???????????????????????????·???????????????????????????????????Oracle Database Vault ~???????????Oracle Database Vault??????????????????????????????(DBA)??????·?????????????????????????????????????????????????????????Oracle Database Vault ~???????????????????????????????????????????????????????????????????????????????????????????????IP????????????????????????????????????????????9:00-17:00?????????????????????????????????????????????????????????????????????????????????????????????????????????????????Oracle Audit Vault ~???????????????????????????????????????·??????????·DBA???????????????????????????????????????????????????????????????????Oracle Audit Vault???Oracle Audit Vault??Oracle Database Vault???????????????????????????????????ID????????????????????????ID????????????????????????????????????????????Oracle Database Standard Edition?Oracle Database Standard Edition One??????????????????Oracle Database Vault???????????Unix?Linux???OS???????????????????????Oracle Database(EE / SE / SE One)??????????????OS??????????????Oracle Identity Manager(???OIM)??????OIM??????????????????????????????ID???????????????ID???·?????????????????ID?????????????????ID????????????????·???????????Oracle Identity Manager ~ID??·????·??????OIM????????????????????(???/???????????)??????????????????????????ID??·? ???·?????????????????????????????????????ID????????????????????????????? ????Oracle Identity Manager ~??·????????????????????ID???????????????????????????????????????OIM?????????????????????????????????????Oracle Identity Manager ~??·??????????????????????1?????????????????????????????????????????????????????????????????Oracle Identity Manager ~????????????????????OIM??ID????????????????????????????????????????????????????????????????? ??40???????????????????????????????????????????????????????????????????? ????????????????????PDF?Office??????????????????????????? Oracle Direct

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  • ????RAC??????????????????????????|WebLogic Channel|??????

    - by ???02
    ????????Oracle Database??????????????Oracle Real Application Clusters(RAC)????????????????????????????????????????????RAC????Oracle WebLogic Server????????????WebLogic Suite 11g?????????WebLogic Server/RAC???????Active GridLink for RAC????????????????????·??????????Frances Zhao?(Oracle Application Server ??????·?????·?????)???????????2??????????(???)?Exalogic???RAC?????WebLogic Suite??????? Oracle Fusion Middleware?????????WebLogic Server?????????????????????????????????????????????/?????????????????????????????????????Fusion Middleware??????Oracle Database??????????????????????????????????????????????? ????????·???????????????????????????????????????????????????????????????????????Oracle Exalogic Elastic Cloud????WebLogic Server???????????????Exalogic???????????????????????????????????????????????????·????????????????????????????????????????????????????????????????????????????? ??Exalogic?????WebLogic Server?Oracle Database???????(RAC)???????????????????????Active GridLink for RAC????????????????RAC???????????????????????????????????????Active GridLink for RAC???????????WebLogic Server???????????·??????WebLogic Suite 11g????????????????????????????RAC???????????Exalogic????????????????WebLogic Server??RAC???????????RAC???????????????? Active GridLink for RAC?????????????????????Oracle Database(RAC)?WebLogic Server???????????????????????2???????????????????????????????????????????????????Active GridLink for RAC??????????????????????????????????????????????RAC Notification Service??????????????????????? Active GridLink for RAC???????????WebLogic Server????RAC?????????????????????????????????????????·????RAC?????????????????·???????RAC???????????????????????????RAC????????????????RAC???RAC?????????????????????????????????????????????????????????????? ????Active GridLink for RAC???????????RAC??????????????1??????????????????WebLogic Server?Active GridLink for RAC????RAC???????????RAC?????????????????????????????????????????????????????RAC???????????????????????????????????????????????????????????????·????????????????????????????Active GridLink for RAC?????????????????·?????RAC??????????????????????Oracle Database/RAC????????????????? ??????????????????Oracle Database 11g R2??????????????Oracle Database???????????????????SCAN(Single Client Access Name)??????????????????RAC??????????????????????Active GridLink for RAC????????WebLogic Server?????????????????????????????????????????????Oracle Data Guard????????????????????????·??????????WebLogic Server?RAC??????????????????????? ??Active GridLink for RAC????????????????????Oracle Notification Service??????????????????????·????????????????????????????????????????????????????????????????????????????????????Active GridLink for RAC?????????????????WebLogic Server Multi Data Sources?????????????????RAC??????????????????????Multi Data Sources??????????????????????????????????RAC???????????TCP/IP????????????????????????????????????????????????? ????Active GridLink for RAC?????Oracle Database?????????????Oracle Notification Service?????????????WebLogic Server???????????????????????????????????????????????????????????????????????????????????????Active GridLink for RAC?????Oracle Database/RAC????????????????????·???????WebLogic Server???????????????????????????????????Active GridLink for RAC???????????????????????

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  • Postgresql: Implicit lock acquisition from foreign-key constraint evaluation

    - by fennec
    So, I'm being confused about foreign key constraint handling in Postgresql. (version 8.4.4, for what it's worth). We've got a couple of tables, mildly anonymized below: device: (id, blah, blah, blah, blah, blah x 50)… primary key on id whooooole bunch of other junk device_foo: (id, device_id, left, right) Foreign key (device_id) references device(id) on delete cascade; primary key on id btree index on 'left' and 'right' So I set out with two database windows to run some queries. db1> begin; lock table device in exclusive mode; db2> begin; update device_foo set left = left + 1; The db2 connection blocks. It seems odd to me that an update of the 'left' column on device_stuff should be affected by activity on the device table. But it is. In fact, if I go back to db1: db1> select * from device_stuff for update; *** deadlock occurs *** The pgsql log has the following: blah blah blah deadlock blah. CONTEXT: SQL statement "SELECT 1 FROM ONLY "public"."device" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF X: update device_foo set left = left + 1; I suppose I've got two issues: the first is that I don't understand the precise mechanism by which this sort of locking occurs. I have got a couple of useful queries to query pg_locks to see what sort of locks a statement invokes, but I haven't been able to observe this particular sort of locking when I run the update device_foo command in isolation. (Perhaps I'm doing something wrong, though.) I also can't find any documentation on the lock acquisition behavior of foreign-key constraint checks. All I have is a log message. Am I to infer from this that any change to a row will acquire an update lock on all the tables which it's foreign-keyed against? The second issue is that I'd like to find some way to make it not happen like that. I'm ending up with occasional deadlocks in the actual application. I'd like to be able to run big update statements that impact all rows on device_foo without acquiring a big lock on the device table. (There's a lot of access going on in the device table, and it's kind of an expensive lock to get.)

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  • Migrating from hand-written persistence layer to ORM

    - by Sergey Mikhanov
    Hi community, We are currently evaluating options for migrating from hand-written persistence layer to ORM. We have a bunch of legacy persistent objects (~200), that implement simple interface like this: interface JDBC { public long getId(); public void setId(long id); public void retrieve(); public void setDataSource(DataSource ds); } When retrieve() is called, object populates itself by issuing handwritten SQL queries to the connection provided using the ID it received in the setter (this usually is the only parameter to the query). It manages its statements, result sets, etc itself. Some of the objects have special flavors of retrive() method, like retrieveByName(), in this case a different SQL is issued. Queries could be quite complex, we often join several tables to populate the sets representing relations to other objects, sometimes join queries are issued on-demand in the specific getter (lazy loading). So basically, we have implemented most of the ORM's functionality manually. The reason for that was performance. We have very strong requirements for speed, and back in 2005 (when this code was written) performance tests has shown that none of mainstream ORMs were that fast as hand-written SQL. The problems we are facing now that make us think of ORM are: Most of the paths in this code are well-tested and are stable. However, some rarely-used code is prone to result set and connection leaks that are very hard to detect We are currently squeezing some additional performance by adding caching to our persistence layer and it's a huge pain to maintain the cached objects manually in this setup Support of this code when DB schema changes is a big problem. I am looking for an advice on what could be the best alternative for us. As far as I know, ORMs has advanced in last 5 years, so it might be that now there's one that offers an acceptable performance. As I see this issue, we need to address those points: Find some way to reuse at least some of the written SQL to express mappings Have the possibility to issue native SQL queries without the necessity to manually decompose their results (i.e. avoid manual rs.getInt(42) as they are very sensitive to schema changes) Add a non-intrusive caching layer Keep the performance figures. Is there any ORM framework you could recommend with regards to that?

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  • How would you structure your entity model for storing arbitrary key/value data with different data t

    - by Nathan Ridley
    I keep coming across scenarios where it will be useful to store a set of arbitrary data in a table using a per-row key/value model, rather than a rigid column/field model. The problem is, I want to store the values with their correct data type rather than converting everything to a string. This means I have to choose either a single table with multiple nullable columns, one for each data type, or a set of value tables, one for each data type. I'm also unsure as to whether I should use full third normal form and separate the keys into a separate table, referencing them via a foreign key from the value table(s), or if it would be better to keep things simple and store the string keys in the value table(s) and accept the duplication of strings. Old/bad: This solution makes adding additional values a pain in a fluid environment because the table needs to be modified regularly. MyTable ============================ ID Key1 Key2 Key3 int int string date ---------------------------- 1 Value1 Value2 Value3 2 Value4 Value5 Value6 Single Table Solution This solution allows simplicity via a single table. The querying code still needs to check for nulls to determine which data type the field is storing. A check constraint is probably also required to ensure only one of the value fields contains non-nulll data. DataValues ============================================================= ID RecordID Key IntValue StringValue DateValue int int string int string date ------------------------------------------------------------- 1 1 Key1 Value1 NULL NULL 2 1 Key2 NULL Value2 NULL 3 1 Key3 NULL NULL Value3 4 2 Key1 Value4 NULL NULL 5 2 Key2 NULL Value5 NULL 6 2 Key3 NULL NULL Value6 Multiple-Table Solution This solution allows for more concise purposing of each table, though the code needs to know the data type in advance as it needs to query a different table for each data type. Indexing is probably simpler and more efficient because there are less columns that need indexing. IntegerValues =============================== ID RecordID Key Value int int string int ------------------------------- 1 1 Key1 Value1 2 2 Key1 Value4 StringValues =============================== ID RecordID Key Value int int string string ------------------------------- 1 1 Key2 Value2 2 2 Key2 Value5 DateValues =============================== ID RecordID Key Value int int string date ------------------------------- 1 1 Key3 Value3 2 2 Key3 Value6 How do you approach this problem? Which solution is better? Also, should the key column be separated into a separate table and referenced via a foreign key or be should it be kept in the value table and bulk updated if for some reason the key name changes?

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  • Syntax error in INSERT INTO statement

    - by user454563
    I wrote a program that connects to MS Access. When I fill in the fields and add a new item to Access the program fails. The exception is "Syntax error in INSERT INTO statement" Here is the relevant code. **************************************************************** AdoHelper.cs **************************************************************** using System; using System.Collections.Generic; using System.Text; using System.Data; using System.Data.OleDb; namespace Yad2 { class AdoHelper { //get the connection string from the app.config file //Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Yad2.accdb static string connectionString = Properties.Settings.Default.DBConnection.ToString(); //declare the db connection static OleDbConnection con = new OleDbConnection(connectionString); /// <summary> /// To Execute queries which returns result set (table / relation) /// </summary> /// <param name="query">the query string</param> /// <returns></returns> public static DataTable ExecuteDataTable(string query) { try { con.Open(); OleDbCommand command = new OleDbCommand(query, con); System.Data.OleDb.OleDbDataAdapter tableAdapter = new System.Data.OleDb.OleDbDataAdapter(command); DataTable dt = new DataTable(); tableAdapter.Fill(dt); return dt; } catch (Exception ex) { throw ex; } finally { con.Close(); } } /// <summary> /// To Execute update / insert / delete queries /// </summary> /// <param name="query">the query string</param> public static void ExecuteNonQuery(string query) { try { con.Open(); System.Data.OleDb.OleDbCommand command = new System.Data.OleDb.OleDbCommand(query, con); command.ExecuteNonQuery(); } catch (Exception ex) { throw ex; } finally { con.Close(); } } /// <summary> /// To Execute queries which return scalar value /// </summary> /// <param name="query">the query string</param> public static object ExecuteScalar(string query) { try { con.Open(); System.Data.OleDb.OleDbCommand command = new System.Data.OleDb.OleDbCommand(query, con); /// here is the Excaption !!!!!!!!! return command.ExecuteScalar(); } catch { throw; } finally { con.Close(); } } } } **************************************************************************** **************************************************************************** DataQueries.cs **************************************************************************** using System; using System.Collections.Generic; using System.Text; using System.Data; namespace Yad2 { class DataQueries { public static DataTable GetAllItems() { try { string query = "Select * from Messages"; DataTable dt = AdoHelper.ExecuteDataTable(query); return dt; } catch (Exception ex) { throw ex; } } public static void AddNewItem(string mesNumber, string title , string mesDate , string contactMail , string mesType , string Details ) { string query = "Insert into Messages values(" + mesNumber + " , '" + title + "' , '" + mesDate + "' , '" + contactMail + "' , , '" + mesType + "' , '" + Details + "')"; AdoHelper.ExecuteNonQuery(query); } public static void DeleteDept(int mesNumber) { string query = "Delete from Item where MessageNumber=" + mesNumber; AdoHelper.ExecuteNonQuery(query); } } } *********************************************************************************************** plase help me .... why the program falls ?

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  • Exchange DEAD! Server recovered but no users can log in

    - by erotsppa
    Yesterday we had a hardware failure and brought our exchange server down. The hardware was repaired and the server was brought back up. Windows server 2008 did the disk check upon bootup and everything was recovered. However, no users can log into their exchange account! This is true with IMAP, Exchange and OWA! All three of them, refused to accept any users. For example when I try to access OWA, I get the following page http://pastie.org/584061 We verified that all the services are up (IMAP, POP, SMTP, IIS etc). We were able to connect to all those services with their respective ports through telnet. What could be the problem? It looks like the database cannot be mounted, from Exchange management console, when I try to mount the database it gives: Microsoft Exchange Error Failed to mount database 'Mailbox Database'. Mailbox Database Failed Error: Exchange is unable to mount the database that you specified. Specified database: SERVER\First Storage Group\Mailbox Database; Error code: MapiExceptionCallFailed: Unable to mount database. (hr=0x80004005, ec=-528) . I read online that there is a repair utility, so I tried it. I navigated to my edb file and ran eseutil /p "Mailbox Database.edb". It printed the following output *Repair completed. Database corruption has been repaired! Note: It is recommended that you immediately perform a full backup of this database. If you restore a backup made before the repair, the database will be rolled back to the state it was in at the time of that backup. Operation completed successfully with 595 (JET_wrnDatabaseRepaired, Database cor ruption has been repaired) after 885.750 seconds.* However I am still unable to mount!

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  • How to bulk insert a CSV file into SQLite C#

    - by Lirik
    I have seen similar questions (1, 2), but none of them discuss how to insert CSV files into SQLite. About the only thing I could think of doing is to use a CSVDataAdapter and fill the SQLiteDataSet, then use the SQLiteDataSet to update the tables in the database: The only DataAdapter for CSV files I found is not actually available: CSVDataAdapter CSVda = new CSVDataAdapter(@"c:\MyFile.csv"); CSVda.HasHeaderRow = true; DataSet ds = new DataSet(); // <-- Use an SQLiteDataSet instead CSVda.Fill(ds); To write to a CSV file: CSVDataAdapter CSVda = new CSVDataAdapter(@"c:\MyFile.csv"); bool InclHeader = true; CSVda.Update(MyDataSet,"MyTable",InclHeader); I found the above code @ http://devintelligence.com/2005/02/dataadapter-for-csv-files/ The CSVDataAdapter was supposed to come with OpenNetCF's SDF, but it doesn't seem to be available anymore. Does anybody know where I can get a CSVDataAdapter? Perhaps somebody knows the much simpler thing: how to do bulk inserts of CSV files into SQLite... your help would be greatly appreciated!

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  • How to bulk insert a CSV file into SQLite

    - by Lirik
    I have seen similar questions (1, 2), but none of them discuss how to insert CSV files into SQLite. About the only thing I could think of doing is to use a CSVDataAdapter and fill the SQLiteDataSet, then use the SQLiteDataSet to update the tables in the database: The only DataAdapter for CSV files I found is not actually available: CSVDataAdapter CSVda = new CSVDataAdapter(@"c:\MyFile.csv"); CSVda.HasHeaderRow = true; DataSet ds = new DataSet(); // <-- Use an SQLiteDataSet instead CSVda.Fill(ds); To write to a CSV file: CSVDataAdapter CSVda = new CSVDataAdapter(@"c:\MyFile.csv"); bool InclHeader = true; CSVda.Update(MyDataSet,"MyTable",InclHeader); I found the above code @ http://devintelligence.com/2005/02/dataadapter-for-csv-files/ The CSVDataAdapter was supposed to come with OpenNetCF's SDF, but it doesn't seem to be available anymore. Does anybody know where I can get a CSVDataAdapter? Perhaps somebody knows the much simpler thing: how to do bulk inserts of CSV files into SQLite... your help would be greatly appreciated!

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  • Where are the factory_girl records?

    - by gmile
    I'm trying to perform an integration test via Watir and RSpec. So, I created a test file within /integration and wrote a test, which adds a test user into a base via factory_girl. The problem is — I can't actually perform a login with my test user. The test I wrote looks as following: ... before(:each) @user = Factory(:user) @browser = FireWatir::Firefox.new end it "should login" @browser.text_field(:id, "username").set(@user.username) @browser.text_field(:id, "password").set(@user.password) @browser.button(:id, "get_in").click end ... As I'm starting the test and see a "performance" in browser, it always fires up a Username is not valid error. I've started an investigation, and did a small trick. First of all I've started to have doubts if the factory actually creates the user in DB. So after the immediate call to factory I've put some puts User.find stuff only to discover that the user is actually in DB. Ok, but as user still couldn't have logged in I've decided to see if he's present in DB with my own eyes. I've added a sleep right after a factory call, and went to see what's in the DB at the moment. I was crushed to see that the user is actually missing there! How come? Still, when I'm trying to output a user within the code, he is actually being fetched from somewhere. So where does the records, made by factory_girl within a runtime lie? Is it test or dev DB? I don't get it. I've 10 times checked if I'm running my Mongrel in test mode (does it matter? I think it does, as I'm trying to tun an integration test) and if my database.yml holds the correct connection specific data. I'm using an authlogic, if that can give any clue (no, putting activate_authlogic doesn't work here).

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  • Rails test db doesn't persist record changes

    - by nathan.f77
    I've been trying to solve a problem for a few weeks now. I am running rspec tests for my Rails app, and they are working fine except for one error that I can't seem get my head around. I am using MySQL with the InnoDB engine. I have set config.use_transactional_fixtures = true in spec_helper.rb I load my test fixtures manually with the command rake spec:db:fixtures:load. The rspec test is being written for a BackgrounDRb worker, and it is testing that a record can have its state updated (through the state_machine gem). Here is my problem: I have a model called Listings. The rspec test calls the update_sold_items method within a file called listing_worker.rb. This method calls listing.sell for a particular record, which sets the listing record's 'state' column to 'sold'. So far, this is all working fine, but when the update_sold_items method finishes, my rspec test fails here: listing = Listing.find_by_listing_id(listing_id) listing.state.should == "sold" expected: "sold", got: "current" (using ==) I've been trying to track down why the state change is not persisting, but am pretty much lost. Here is the result of some debugging code that I placed in the update_sold_items method during the test: pp listing.state # => "current" listing.sell! listing.save! pp listing.state # => "sold" listing.reload pp listing.state # => "current" I cannot understand why it saves perfectly fine, but then reverts back to the original record whenever I call reload, or Listing.find etc. Thanks for reading this, and please ask any questions if I haven't given enough information. Thanks for your help, Nathan B P.S. I don't have a problem creating new records for other classes, and testing those records. It only seems to be a problem when I am updating records that already exist in the database.

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  • Good DB Migrations for CakePHP?

    - by Martin Westin
    Hi, I have been trying a few migration scripts for CakePHP but I ran into problems with all of the in some form or another. Please advice me on a migration option for Cake that you use live and know works. I'd like the following "features": -Support CakePHP 1.2(e.g. CakeDCs migrations will only be an option when 1.3 is stable and my app migrated to the new codebase) -Support for (or at least not halt on) Models with a different database config. -Support Models in sub-folders of app/models -Support Models in plugins -Support tables that do not conform to Cake conventions (I have a few special tables that do not have a single primary key field and need to keep them) -Plays well with automated deployment via Capistrano and Git. I do not need rails-style versioned files a git versioned schema file that is compared live to the existing schema will do. That is: I like the SchemaShell in Cake apart from it not being compatible with most of my requirements above. I have looked at and tested: CakePHP Schema Shell http://book.cakephp.org/view/734/Schema-management-and-migrations CakeDC migrations http://cakedc.com/downloads/view/cakephp_migrations_plugin YAML migrations http://github.com/georgious/cakephp-yaml-migrations-and-fixtures joelmoss migrations http://code.google.com/p/cakephp-migrations

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  • What scalability problems have you solved using a NoSQL data store?

    - by knorv
    NoSQL refers to non-relational data stores that break with the history of relational databases and ACID guarantees. Popular open source NoSQL data stores include: Cassandra (tabular, written in Java, used by Facebook, Twitter, Digg, Rackspace, Mahalo and Reddit) CouchDB (document, written in Erlang, used by Engine Yard and BBC) Dynomite (key-value, written in C++, used by Powerset) HBase (key-value, written in Java, used by Bing) Hypertable (tabular, written in C++, used by Baidu) Kai (key-value, written in Erlang) MemcacheDB (key-value, written in C, used by Reddit) MongoDB (document, written in C++, used by Sourceforge, Github, Electronic Arts and NY Times) Neo4j (graph, written in Java, used by Swedish Universities) Project Voldemort (key-value, written in Java, used by LinkedIn) Redis (key-value, written in C, used by Engine Yard, Github and Craigslist) Riak (key-value, written in Erlang, used by Comcast and Mochi Media) Ringo (key-value, written in Erlang, used by Nokia) Scalaris (key-value, written in Erlang, used by OnScale) ThruDB (document, written in C++, used by JunkDepot.com) Tokyo Cabinet/Tokyo Tyrant (key-value, written in C, used by Mixi.jp (Japanese social networking site)) I'd like to know about specific problems you - the SO reader - have solved using data stores and what NoSQL data store you used. Questions: What scalability problems have you used NoSQL data stores to solve? What NoSQL data store did you use? What database did you use before switching to a NoSQL data store? I'm looking for first-hand experiences, so please do not answer unless you have that.

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  • JAXB, BigDecimal or double?

    - by Alex
    I working on different web-services, and I always use WSDL First. JAXB generates for a Type like: <xsd:simpleType name="CurrencyFormatTyp"> <xsd:restriction base="xsd:decimal"> <xsd:totalDigits value="13"/> <xsd:fractionDigits value="2"/> <xsd:minInclusive value="0.01"/> </xsd:restriction> </xsd:simpleType> a Java binding type BigDecimal (as it's mentioned in JAXB specification). When I then do some simple arithmetic operation with values of the type double (which are stored in a database and mapped via hibernate to the type double) I run into trouble. <ns5:charge>0.200000000000000011102230246251565404236316680908203125</ns5:charge> <ns5:addcharge>0.0360000000000000042188474935755948536098003387451171875</ns5:addcharge> <ns5:tax>0.047199999999999998900879205621095024980604648590087890625</ns5:tax> <ns5:totalextax>0.2360000000000000153210777398271602578461170196533203125</ns5:totalextax> What would be the right way? Convert all my values into double (JAXB binding from BigDecimal to double) Hibernate mapping double to Bigdecimal and do all my arithmetic operations in one object type.

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  • Violating 1st normal form, is it okay for my purpose?

    - by Nick
    So I'm making a running log, and I have the workouts stored as entries in a table. For each workout, the user can add intervals (which consist of a time and a distance), so I have an array like this: [workout] => [description] => [comments] => ... [intervals] => [0] => [distance] => 200m [time] => 32 [1] => [distance] => 400m [time] => 65 ... I'm really tempted to throw the "intervals" array into serialize() or json_encode() and put it in an "intervals" field in my table, however this violates the principles of good database design (which, incidentally, I know hardly anything about). Is there any disadvantage to doing this? I never plan on querying my table based on the contents of "intervals". Creating a separate table just for intervals seems like a lot of unnecessary complexity, so if anyone with more experience has had a situation like this, what route did you take and how did it work out?

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  • Django Models / SQLAlchemy are bloated! Any truly Pythonic DB models out there?

    - by Luke Stanley
    "Make things as simple as possible, but no simpler." Can we find the solution/s that fix the Python database world? from someAmazingDB import * class Task (model): title = '' isDone = False db.taskList = [] #or db.taskList = expandableTypeCollection(Task) #not sure what this syntax would be db['taskList'].append(Task(title='Beat old sql interfaces',done=False)) db.taskList.append(Task('Illustrate different syntax modes',True)) #at this point it should autosave #we should be able to reload the console and access like: >> from someAmazingDB import * >> print 'Done tasks:' >> for task in db.taskList: >> if task.done: >> print task 'Illustrate different syntax modes' I'm a fan of Python, webPy and Cherry Py, and KISS in general. We're talking automatic Python to SQL type translation or NoSQL. We don't have to totally be SQL compatible! Just a scalable subset or ignore it! Re:model changes, it's ok to ask the developer when they try to change it or have a set of sensible defaults. Here is the challenge: The above code should work with very little modification or thinking required. Why must we put up with compromise when we know better? It's 2010, we should be able to code scalable, simple databases in our sleep. If you think this is important, please upvote!

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  • Storing URLs while Spidering

    - by itemio
    I created a little web spider in python which I'm using to collect URLs. I'm not interested in the content. Right now I'm keeping all the visited URLs in a set in memory, because I don't want my spider to visit URLs twice. Of course that's a very limited way of accomplishing this. So what's the best way to keep track of my visited URLs? Should I use a database? * which one? MySQL, sqlite, postgre? * how should I save the URLs? As a primary key trying to insert every URL before visiting it? Or should I write them to a file? * one file? * multiple files? how should I design the file-structure? I'm sure there are books and a lot of papers on this or similar topics. Can you give me some advice what I should read?

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  • EJB3Unit testing no-tx-datasource

    - by justastefan
    Hello, I am doing tests on an ejb3-project using ejb3unit http://ejb3unit.sourceforge.net/Session-Bean.html for testing. All my Services long for @PersistenceContext (UnitName=bla). I set up the ejb3unit.properties like this: ejb3unit_jndi.1.isSessionBean=true ejb3unit_jndi.1.jndiName=ejb/MyServiceBean ejb3unit_jndi.1.className=com.company.project.MyServiceBean everything works with the in-memory-database. So now i want additionally test another servicebean with @PersistenceContext (UnitName=noTxDatasource) that goes for a defined in my datasources.xml: <datasources> <local-tx-datasource> ... </local-tx-datasource> <no-tx-datasource> <jndi-name>noTxDatasource</jndi-name> <connection-url>...</connection-url> <driver-class>oracle.jdbc.OracleDriver</driver-class> <user-name>bla</user-name> <password>bla</password> </no-tx-datasource> </datasources> How do I tell ejb3unit to make this work: Object object = InitialContext.doLookup("java:/noTxDatasource"); if (object instanceof DataSource) { return ((DataSource) object).getConnection(); } else { return null; } Currently it fails saying: javax.NamingException: Cannot find the name (noTxDataSource) in the JNDI tree Current bindings: (ejb/MyServiceBean=com.company.project.MyServiceBean) How can I add this no-tx-datasource to the jndi bindings?

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  • get cells odf a JTable

    - by tuxou
    hi how to display a row of a jtable in a from of JTextField when click on the row, ( I need this to edit the data base from the JTable ) My table model static class TableDataModel extends AbstractTableModel { private List nomColonnes; private List tableau; public TableDataModel(List nomColonnes, List tableau){ this.nomColonnes = nomColonnes; majDonnees(tableau); } public void majDonnees(List nouvellesDonnees){ this.tableau = nouvellesDonnees; fireTableDataChanged(); } public int getRowCount(){ return tableau.size(); } public int getColumnCount(){ return nomColonnes.size(); } public Object getValueAt(int row, int col){ return ((ArrayList)( tableau.get(row))).get(col); } public String getColumnName(int col){ return nomColonnes.get(col).toString(); } public Class getColumnClass(int c) { return getValueAt(0,c).getClass(); } public boolean isCellEditable(int row, int col){ return true; } public void setValueAt(Object value, int row, int col) { ((List)tableau.get(row)).set(col,value); fireTableCellUpdated(row, col); //i suppose i should update the database here } }

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  • Help me with DB design

    - by eugeneK
    Hi, i'm developing text ads system. Some small clone of Google Ads. Here is diagram with common tables. Basically make it short, advertiser can have up to 10 variant of same campaign with different text variations, can geo-target his ads and unique impressions count only for IP that haven't been on certain site for more than 24 hours. Pretty simple but the question is what i lack in here from your experience because later it would much harder to fix design flaws and some of you probably done something alike also many SQL gurus in here so maybe i did over normalized DB or did not normalized as needed ? Second question is. My end goal is to get ads for user from ie. Germany that haven't seen same ad on same site for 24 hours as long as ads fit country of user. Each impression is count same as each click if there is one. I need to get 5 "random" ads based on IP, Country and higher CPC (pay per click). How can i achieve this with current design or maybe to design database the way it would be easy to get ads and show stats for advirtisers... thanks for any help...

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  • Is there a way to effect user defined data types in MySQL?

    - by Dancrumb
    I have a database which stores (among other things), the following pieces of information: Hardware IDs BIGINTs Storage Capacities BIGINTs Hardware Names VARCHARs World Wide Port Names VARCHARs I'd like to be able to capture a more refined definition of these datatypes. For instance, the hardware IDs have no numerical significance, so I don't care how they are formatted when displayed. The Storage Capacities, however, are cardinal numbers and, at a user's request, I'd like to present them with thousands and decimal separators, e.g. 123,456.789. Thus, I'd like to refine BIGINT into, say ID_NUMBER and CARDINAL. The same with Hardware Names, which are simple text and WWPNs, which are hexstrings, e.g. 24:68:AC:E0. Thus, I'd like to refine VARCHAR into ENGLISH_WORD and HEXSTRING. The specific datatypes I made up are just for illustrative purposes. I'd like to keep all this information in one place and I'm wondering if anybody knows of a good way to hold this all in my MySQL table definitions. I could use the Comment field of the table definition, but that smells fishy to me. One approach would be to define the data structure elsewhere and use that definition to generate my CREATE TABLEs, but that would be a major rework of the code that I currently have, so I'm looking for alternatives. Any suggestions? The application language in use is Perl, if that helps.

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  • Help regarding composite pattern with hibernate

    - by molleman
    Hello, So i am stuck, i am creating a gwt web application, i will be using a tree(gwt Tree and TreeItems) structure to show a list of folders(class Folder) and files(class FileLocation), the folder and filelocation class will all implement a Hierarchy interface basing the classes on the composite pattern. but i am using hibernate to store my data , and i am using annotations for the mapping of the data to the database. my trouble is i do not know how to annotate my interface. have any of you guys used the composite pattern while persisting the data with hibernate public interface Hierarchy(){ // a few abstract methods that will be implemented by the sub classes } @Entity @Table() public class Folder extends Hierarchy implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "folder_id", updatable = false, nullable = false) private int id; @OneToMany(cascade = CascadeType.ALL,fetch = FetchType.EAGER) @JoinTable(name = "FOLDER_FILELOCATION", joinColumns = { @JoinColumn(name = "folder_id") }, inverseJoinColumns = { @JoinColumn(name = "file_information_id") }) private List<Hierarchy> children = new ArrayList<Hierarchy>() ; @Column(name = "folder_name") private String folderName; @Column(name = "tree_item") private TreeItem item; @Column (name = "parent") private Hierarchy parent; @Entity @Table(name = "FILE_INFORMATION_TABLE") public class FileInformation extends Hierarchy implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "file_information_id", updatable = false, nullable = false) private int fiId; @Column (name = "location") private String location; @Column(name = "tree_item") private TreeItem item; @Column (name = "parent") private Hierarchy parent;

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  • Add new row in a databound form with a Oracle Sequence as the primary key

    - by Ranhiru
    I am connecting C# with Oracle 11g. I have a DataTable which i fill using an Oracle Data Adapter. OracleDataAdapter da; DataTable dt = new DataTable(); da = new OracleDataAdapter("SELECT * FROM Author", con); da.Fill(dt); I have few text boxes that I have databound to various rows in the data table. txtAuthorID.DataBindings.Add("Text", dt, "AUTHORID"); txtFirstName.DataBindings.Add("Text", dt, "FIRSTNAME"); txtLastName.DataBindings.Add("Text", dt, "LASTNAME"); txtAddress.DataBindings.Add("Text", dt, "ADDRESS"); txtTelephone.DataBindings.Add("Text", dt, "TELEPHONE"); txtEmailAddress.DataBindings.Add("Text", dt, "EMAIL"); I also have a DataGridView below the Text Boxes, showing the contents of the DataTable. dgvAuthor.DataSource = dt; Now when I want to add a new row, i do bm.AddNew(); where bm is defined in Form_Load as BindingManagerBase bm; bm = this.BindingContext[dt]; And when the save button is clicked after all the information is entered and validated, i do this.BindingContext[dt].EndCurrentEdit(); try { da.Update(dt); } catch (Exception ex) { MessageBox.Show(ex.Message); } However the problem comes where when I usually enter a row to the database (using SQL Plus) , I use a my_pk_sequence.nextval for the primary key. But how do i specify that when i add a new row in this method? I catch this exception ORA-01400: cannot insert NULL into ("SYSMAN".AUTHOR.AUTHORID") which is obvious because nothing was specified for the primary key. How do get around this? Thanx a lot in advance :)

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