Search Results

Search found 31694 results on 1268 pages for 'database administration'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 307/1268 | < Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >

  • Star-schema: Separate dimensions for clients and non-clients or shared dimension for attendants?

    - by celopes
    I'm new to modeling star schemas, fresh from reading the Data Warehouse Toolkit. I have a business process that has clients and non-clients calling into conference calls with some of our employees. My fact table, call it "Audience", will contain a measure of how long an attending person was connected to the call, and the cost per minute of this person's connection to the call. The grain is "individual connection to the conference call". Should I use my conformed Client dimension and create a non-client dimension (for the callers that are not yet clients) this way (omitting dimensions that are not part of this questions): Or would it be OK/better to have a non-conformed Attending dimension related to the conformed Client dimension in this manner: Or is there a better/standard mechanism to model business processes like this one?

    Read the article

  • Dynamic Typed Table/Model in J2EE?

    - by Viele
    Hi, Usually with J2EE when we create Model, we define the fields and types of fields through XML or annotation before compilation time. Is there a way to change those in runtime? or better, is it possible to create a new Model based on the user's input during the runtime? such that the number of columns and types of fields are dynamic (determined at runtime)? Help is much appreciated. Thank you.

    Read the article

  • How may I create an horizontal view from a tree table

    - by Giuseppe Alfieri
    I want to create a view for each tree for each customer of this 3 table structured in this way: Fields: db_attrib.name, db_attrib.name, db_attrib.name until the last db_tree.id_child = 0 Values: db_attrib_values.value where db_attrib.id = db_attrib_value.id_attrib and so on for each child And so on for each db_tree.id This is the link to sql fiddle with the prepared structure: http://sqlfiddle.com/#!9/21516

    Read the article

  • NHibernate - Stream large result sets?

    - by Dan Black
    Hi, I have to read in a large record set, process it, then write it out to a flat file. The large result set comes from a Stored Proc in SQL 2000. I currently have: var results = session.CreateSQLQuery("exec usp_SalesExtract").List(); I would like to be able to read the result set row by row, to reduce the memory foot print Thanks

    Read the article

  • What's the best way to store sort order in SQL?

    - by Duracell
    The guys at the top want sort order to be customizable in our app. So I have a table that effectively defines the data type. What is the best way to store our sort order. If I just created a new column called 'Order' or something, every time I updated the order of one row I imagine I would have to update the order of every row to ensure posterity. Is there a better way to do it?

    Read the article

  • Why is MySQL with InnoDB doing a table scan when key exists and choosing to examine 70 times more ro

    - by andysk
    Hello, I'm troubleshooting a query performance problem. Here's an expected query plan from explain: mysql> explain select * from table1 where tdcol between '2010-04-13:00:00' and '2010-04-14 03:16'; +----+-------------+--------------------+-------+---------------+--------------+---------+------+---------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------------+-------+---------------+--------------+---------+------+---------+-------------+ | 1 | SIMPLE | table1 | range | tdcol | tdcol | 8 | NULL | 5437848 | Using where | +----+-------------+--------------------+-------+---------------+--------------+---------+------+---------+-------------+ 1 row in set (0.00 sec) That makes sense, since the index named tdcol (KEY tdcol (tdcol)) is used, and about 5M rows should be selected from this query. However, if I query for just one more minute of data, we get this query plan: mysql> explain select * from table1 where tdcol between '2010-04-13 00:00' and '2010-04-14 03:17'; +----+-------------+--------------------+------+---------------+------+---------+------+-----------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------------+------+---------------+------+---------+------+-----------+-------------+ | 1 | SIMPLE | table1 | ALL | tdcol | NULL | NULL | NULL | 381601300 | Using where | +----+-------------+--------------------+------+---------------+------+---------+------+-----------+-------------+ 1 row in set (0.00 sec) The optimizer believes that the scan will be better, but it's over 70x more rows to examine, so I have a hard time believing that the table scan is better. Also, the 'USE KEY tdcol' syntax does not change the query plan. Thanks in advance for any help, and I'm more than happy to provide more info/answer questions.

    Read the article

  • problem sybase autogenerated ids

    - by daedlus
    Hi , I have a table in which the PK column Id of type bigint and it is populated automatically increasing order of 1,2,3...so on i notice that some times all of a sudden the ids that are generated are having very big value . for example the ids are like 1,2,3,4,5,500000000000001,500000000000002 there is a huge jump after 5...ids 6 , 7 were not used at all i do perform delete operations on this table but i am absolutely sure that missing ids were not used before. why does this occur and how can i fix this? many thanks for looking in to this. my env: sybase ase 15.0.3 , linux

    Read the article

  • Mapping a ER model to Rails

    - by Thiago
    Hi there, I want to map the following ER schema to rails: I have an entity called "user" which has a self relationship called "has friend", which has an attribute called "status". In code, I would like to run: User.friends and it should return me an array of users, containing the users that I'm friend of. It shouldn't matter in which side of the relationship I am (i.e. whether I'm the friender or the friendee). Any thoughts?

    Read the article

  • User account design and security...

    - by espinet
    Before I begin, I am using Ruby on Rails and the Devise gem for user authentication. Hi, I was doing some research about account security and I found a blog post about the topic awhile ago but I can no longer find it again. I read something about when making a login system you should have 1 model for User, this contains a user's username, encrypted password, and email. You should also have a model for a user's Account. This contains everything else. A User has an Account. I don't know if I'm explaining this correctly since I haven't seen the blog post for several months and I lost my bookmark. Could someone explain how and why I should or shouldn't do this. My application deals with money so I need to cover my bases with security. Thanks.

    Read the article

  • Strategy for Offline/Online data synchronization

    - by Adi
    My requirement is I have server J2EE web application and client J2EE web application. Sometimes client can go offline. When client comes online he should be able to synchronize changes to and fro. Also I should be able to control which rows/tables need to be synchronized based on some filters/rules. Is there any existing Java frameworks for doing it? If I need to implement on my own, what are the different strategies that you can suggest? One solution in my mind is maintaining sql logs and executing same statements at other side during synchronization. Do you see any problems with this strategy?

    Read the article

  • Tools to work with App Engine data dumps

    - by Thilo
    Using the bulkloader.py utility you can download all data from your application's Datastore. It is not obvious how the data is stored, however. From the looks of it, you get a SQLite file with all data in binary format in a single table: sqlite> .tables bulkloader_database_signature result sqlite> .schema result CREATE TABLE result ( id BLOB primary key, value BLOB not null, sort_key BLOB); Are there any tools to work with this data?

    Read the article

  • bidirectional habtm linking

    - by Alexey Poimtsev
    Hi, all. I have application with 2 groups of models - content based (news, questions) and "something" based (devices, applications etc). I need to link all models between groups - for example question may belongs to 3 different things - one application and 2 devices. The same - for news. From other side - i need to see all news articles and questions related to some application or device. Any idea how to develop this in rails? I have only one idea - mixins that will add methods content_id and thing_id to models and join table.

    Read the article

  • Are Parameters really enough to prevent Sql injections?

    - by Rune Grimstad
    I've been preaching both to my colleagues and here on SO about the goodness of using parameters in SQL queries, especially in .NET applications. I've even gone so far as to promise them as giving immunity against SQL injection attacks. But I'm starting to wonder if this really is true. Are there any known SQL injection attacks that will be successfull against a parameterized query? Can you for example send a string that causes a buffer overflow on the server? There are of course other considerations to make to ensure that a web application is safe (like sanitizing user input and all that stuff) but now I am thinking of SQL injections. I'm especially interested in attacks against MsSQL 2005 and 2008 since they are my primary databases, but all databases are interesting. Edit: To clarify what I mean by parameters and parameterized queries. By using parameters I mean using "variables" instead of building the sql query in a string. So instead of doing this: SELECT * FROM Table WHERE Name = 'a name' We do this: SELECT * FROM Table WHERE Name = @Name and then set the value of the @Name parameter on the query / command object.

    Read the article

  • IntegrityError: foreign key violation upon delete

    - by Lukasz Korzybski
    I have Order and Shipment model. Shipment has a foreign key to Order. class Order(...): ... class Shipment() order = m.ForeignKey('Order') ... Now in one of my views I want do delete order object along with all related objects. So I invoke order.delete(). I have Django 1.0.4, PostgreSQL 8.4 and I use transaction middleware, so whole request is enclosed in single transaction. The problem is that upon order.delete() I get: ... File "/usr/local/lib/python2.6/dist-packages/django/db/backends/__init__.py", line 28, in _commit return self.connection.commit() IntegrityError: update or delete on table "main_order" violates foreign key constraint "main_shipment_order_id_fkey" on table "main_shipment" DETAIL: Key (id)=(45) is still referenced from table "main_shipment". I checked in connection.queries that proper queries are executed in proper order. First shipment is deleted, after that django executes delete on order row: {'time': '0.000', 'sql': 'DELETE FROM "main_shipment" WHERE "id" IN (17)'}, {'time': '0.000', 'sql': 'DELETE FROM "main_order" WHERE "id" IN (45)'} Foreign key have ON DELETE NO ACTION (default) and is initially deferred. I don't know why I get foreign key constraint violation. I also tried to register pre_delete signal and manually delete shipment objects before delete on order is called, but it resulted in the same error. I can change ON DELETE behaviour for this key in Postgres but it would be just a hack, I wonder if anyone has a better idea what's going on here. There is also a small detail, my Order model inherits from Cart model, so it actually doesn't have id field but cart_ptr_id and after DELETE on order is executed there is also DELETE on cart, but it seems unrelated? to the shipment-order problem so I simplified it in the example.

    Read the article

  • please help me to interpret the naive bayes result in weka..

    - by resmi
    Anybody please help me to interpret the following result generated in weka for classification using naive bayes.....Please explain clearly what is this Normal Distribution , Mean , StandardDev , WeightSum and Precision.Please help me.Am new in weka. ** Naive Bayes Classifier Class Normal: Prior probability = 0.5 1374195_at: Normal Distribution. Mean = 218.06 StandardDev = 6.0572 WeightSum = 3 Precision = 36.34333334 1373315_at: Normal Distribution. Mean = 1142.58 StandardDev = 21.1589 WeightSum = 3 Precision = 126.95333339999999

    Read the article

  • Avoiding Duplicate Data in DB (for use with Rails)

    - by ants
    I have five tables that I am trying to get to work nicely together but may need some help. I have three main tables: accounts members and roles. With two join tables account_members and account_member_roles. The accounts and members table are joined by account_members (fk account_id and member_id) table. The other 2 tables are the problem (roles and account_member_roles). A member of an account can have more than one role and I have the account_member_roles (fk account_member_id and role_id) table joining the account_members join table and the roles table. That seems logical but can you have a relationship with a join table? What I'd like to be able to do is when creaeting an account, for instance, I would like @account.save to include the roles and update the account_member_roles table neatly ..... but through the account_members join table. I've tried ..... accept_nested_attributes_for :members, :account_member_roles in the account.rb but I get ..... ActiveRecord::HasManyThroughCantAssociateThroughHasManyReflection (Cannot modify association 'Account#account_member_roles' because the source reflection class 'AccountMemberRole' is associated to 'AccountMember' via :has_many.) upon trying to save a record. Any advice on how I should approach this? CIA -ants

    Read the article

  • Complex SQL query... 3 tables and need the most popular in the last 24 hours using timestamps!

    - by Stefan
    Hey guys, I have 3 tables with a column in each which relates to one ID per row. I am looking for an sql statement query which will check all 3 tables for any rows in the last 24 hours (86400 seconds) i have stored timestamps in each tables under column time. After I get this query I will be able to do the next step which is to then check to see how many of the ID's a reoccurring so I can then sort by most popular in the array and limit it to the top 5... Any ideas welcome! :) Thanks in advanced. Stefan

    Read the article

  • SQL query performance optimization (TimesTen)

    - by Sergey Mikhanov
    Hi community, I need some help with TimesTen DB query optimization. I made some measures with Java profiler and found the code section that takes most of the time (this code section executes the SQL query). What is strange that this query becomes expensive only for some specific input data. Here’s the example. We have two tables that we are querying, one represents the objects we want to fetch (T_PROFILEGROUP), another represents the many-to-many link from some other table (T_PROFILECONTEXT_PROFILEGROUPS). We are not querying linked table. These are the queries that I executed with DB profiler running (they are the same except for the ID): Command> select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; < 1169655247309537280 > < 1169655249792565248 > < 1464837997699399681 > 3 rows found. Command> select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; < 1169655247309537280 > 1 row found. This is what I have in the profiler: 12:14:31.147 1 SQL 2L 6C 10825P Preparing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272 12:14:31.147 2 SQL 4L 6C 10825P sbSqlCmdCompile ()(E): (Found already compiled version: refCount:01, bucket:47) cmdType:100, cmdNum:1146695. 12:14:31.147 3 SQL 4L 6C 10825P Opening: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.147 4 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.148 5 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.148 6 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.228 7 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:31.228 8 SQL 4L 6C 10825P Closing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1464837998949302272; 12:14:35.243 9 SQL 2L 6C 10825P Preparing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928 12:14:35.243 10 SQL 4L 6C 10825P sbSqlCmdCompile ()(E): (Found already compiled version: refCount:01, bucket:44) cmdType:100, cmdNum:1146697. 12:14:35.243 11 SQL 4L 6C 10825P Opening: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 12 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 13 SQL 4L 6C 10825P Fetching: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; 12:14:35.243 14 SQL 4L 6C 10825P Closing: select G.M_ID from T_PROFILECONTEXT_PROFILEGROUPS CG, T_PROFILEGROUP G where CG.M_ID_EID = G.M_ID and CG.M_ID_OID = 1466585677823868928; It’s clear that the first query took almost 100ms, while the second was executed instantly. It’s not about queries precompilation (the first one is precompiled too, as same queries happened earlier). We have DB indices for all columns used here: T_PROFILEGROUP.M_ID, T_PROFILECONTEXT_PROFILEGROUPS.M_ID_OID and T_PROFILECONTEXT_PROFILEGROUPS.M_ID_EID. My questions are: Why querying the same set of tables yields such a different performance for different parameters? Which indices are involved here? Is there any way to improve this simple query and/or the DB to make it faster? UPDATE: to give the feeling of size: Command> select count(*) from T_PROFILEGROUP; < 183840 > 1 row found. Command> select count(*) from T_PROFILECONTEXT_PROFILEGROUPS; < 2279104 > 1 row found.

    Read the article

  • Rails: translations for table's column.

    - by Andrew
    In rails application I have two models: Food and Drink. Both food and drink have a name, which has to be stored in two languages. How do I better realize translations for theese tables? First solution I realized was to replace name column with name_en and name_ru. Another solution is to encode with YAML hash like { :en => 'eng', :ru => 'rus' } and store yaml as a name. What would you recommend, assuming content is not static? Maybe there's good article?

    Read the article

  • MySQL slow query

    - by andrhamm
    SELECT items.item_id, items.category_id, items.title, items.description, items.quality, items.type, items.status, items.price, items.posted, items.modified, zip_code.state_prefix, zip_code.city, books.isbn13, books.isbn10, books.authors, books.publisher FROM ( ( items LEFT JOIN bookitems ON items.item_id = bookitems.item_id ) LEFT JOIN books ON books.isbn13 = bookitems.isbn13 ) LEFT JOIN zip_code ON zip_code.zip_code = items.item_zip WHERE items.rid = $rid` I am running this query to get the list of a user's items and their location. The zip_code table has over 40k records and this might be the issue. It currently takes up to 15 seconds to return a list of about 20 items! What can I do to make this query more efficient?

    Read the article

  • how relate one table to another for future records

    - by Sinan
    I have a games table which holds the data about a game. Then another table which holds the data about news. So far so good. First I thought about creating a junction table for game_news so I could relate news to games. This way works as intended when the game exists. So whenever I insert a news I can relate it to a game using the junction table. However there are cases when there is news about game but the game isn't published and it doesn't exists. So my question would be; is there a way to relate these news to a particular game when the game record is created. What is the best way to do this? Any ideas?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >