Hi SO, I have a question: I have two MSSQL tables, items and states, that are linked together via a stateid: STATES ITEMS ------------- --------------------------- | id | name | | id | name | ... | stateid V ^ |_____________________________________| So Items.StateID i...
Howdy peeps. I hope you can help me with this one. I got a twitter service ( http://foller.me ) which is about to be updated to public beta 2, but I don't want to do this until I could give the pages out in at least 2 or 3 seconds. The current version is simple enough, but the dev version I'm working on is quite complex. It's all about...
Are there any ways to determine what the differences in databases are that affect a SSIS package load performance ? I've got a package which loads and does various bits of processing on ~100k records on my laptop database in about 5 minutes Try the same package and same data on the test server, which is a reasonable box in both CPU and...
I'm playing with LINQ-To-SQL in .NET 3.5 and have built some classes based on an underlying database. I now face the decision: do I validate data in the class code, or in the database? I can see pros and cons either way. If I do validation in the database, the validation takes place no matter what app is using the database. (I currently...
Hi, How do you guys decide that you should be wrapping the sql in a transaction? Please throw some light on this. Cheers !! ...
Consider this scenario with the following assumptions: The database is used for a non-critical webapp. Query speed is of vital importance. The read/write patterns are roughly >95 % reads and <5 % writes. The database is backuped up daily using mysqldump. The is no need for transactions or advanced crash recovery. If the database crash...
Hi, I want to know that what is the best way to arrive at the isolation level of the transaction? This is a good link of the available ISOLATION levels. Blockquote It will be nice if someone can explain the various isolation levels of a transaction ...
We have 3 databases that are physically separated by region, one in LA, SF and NY. All the databases share the same schema but contain data specific to their region. We're looking to merge these databases into one and mirror it. We need to preserve the data for each region but merge them into one db. This presents quite a few issues for ...
I'm a low-level algorithm programmer, and databases are not really my thing - so this'll be a n00b question if ever there was one. I'm running a simple SELECT query through our development team's DAO. The DAO returns a System.Data.DataTable object containing the results of the query. This is all working fine so far. The problem I h...
Obviously, an index would work well if a column has a few distinct values. Will creating an index on a column where nearly every entry is unique be effective (such as a created_on (DATE) column)? ...
How can I automatically kill a query that runs for more than 60 seconds? The queries are called from a VB ASPX page to an Oracle database. I don't mind putting the limit in the database itself or in the calling aspx code. FYI: I use a asp:GridView bound to a 'asp:SqlDataSource` for querying the database. FYI: A connectionString for S...
I should probably know this by now, but what, if any is the difference between the two statements below? The nested join: SELECT t1.* FROM table1 t1 INNER JOIN table2 t2 LEFT JOIN table3 t3 ON t3.table3_ID = t2.table2_ID ON t2.table2_ID = t1.table1_ID The more traditional join: SELECT t1.* FROM table1 t1...
Just curious what is the best practice for solving the following issue. I have institutions, accounts and users tables. Institutions and accounts have a one-to-many relationship. Institutions and users have a one-to-many relationship. Users and accounts have a many-to-many relationship or alternatively they could have a many-to-al...
I need a way to insert new articles straight into my MediaWiki database without damaging the wiki installation. I'm guessing if I knew what tables/attributes MediaWiki inserts to when creating a new article then I could fill them in myself. Does anyone know a better way or have any suggestions? ...
The problem: Maintain a bidirectional many-to-one relationship among java objects. Something like the Google/Commons Collections bidi maps, but I want to allow duplicate values on the forward side, and have sets of the forward keys as the reverse side values. Used something like this: // maintaining disjoint areas on a gameboard. Locat...
I have a database infrastructure where we are regularly (at least once a day) replicating the full content of tables from a source database to approximately 20 target databases. Due to the replication code in use (we have to use regular oracle queries, no control or direct access to source database) - this results in 20 full-table sorts ...
A friend of mine who is a computer scientist told me he thinks SQL is a thing of the past. I used SQL for years and think the language is totally relevant when dealing with database specific tasks. My friend believes the new frameworks (e.g.: django, etc) that are coming out are making things even more generic, making SQL an outdated d...
The Media Wiki database Schema, here, has taught me a lot. Cannot-understand: In contrast, it seems rare that other services of the size, such as Youtube, publish their database schema. Oddly, some of such services have presently opened APIs, but not schemas. Question: What is the relationship between schemas and APIs? Why are some sch...
I have two models, associated with a HABTM (actually using has_many :through on both ends, along with a join table). I need to retrieve all ModelAs that is associated with BOTH of two ModelBs. I do NOT want all ModelAs for ModelB_1 concatenated with all ModelAs for ModelB_2. I literally want all ModelAs that are associated with BOTH Mode...
I am working on an employee objectives web application. Lead/Manager sets objectives for team members after discussing with them. This is an yearly/half-yearly/quarterly depending on appraisal cycle the organization follows. Now question is is better approach to add time period based fields or archive previous quarter's/year's data. Wh...