I have a database of automobile classified listings. After 90 days, the classified listing is no longer valid to be displayed (the listing expires); however, I want to retain the listing for archive purposes. Question: From a database design best practice perspective as well as query performance, is it better to keep the old listing A)...
I have in my MySQL database both longitude and latitude coordinates (GPS data). It's currently stored as: column type ------------------------ geolat decimal(10,6) geolng decimal(10,6) Question: Do I really need a data type as large as decimal(10,6) to properly store coordinate data? Since I have a combined index on the...
Where can i get any Screencasts, Webcasts, Training Video's, Cbt's ect for PostgreSQL? Thank you in advance ...
Let's say I need to issue a number of queries against a relational database, which of the following would be better from performance perspective: Issue them one by one, being able to use data from the first ones as input in the secondary ones (meaning multiple connections made, but less joins/subselects). Batch the commands together (m...
Hello! I want to make a relational database system for a local computer hardware non-profit. There are two inter-related features that I want to figure out how to implement. First, we need to manage our inventory of parts, and second, we need to track donations of computer systems as they come into us, and also as we grant them out. Fir...
Hi all, I think I have the use of reference constraints in RDBMS's a bit mixed up. Take this example for instance: Table folder Table file (with FK_folder) A file record is a child of a folder record. When I want a user to delete a folder I want to warn them if there are files located in the folder. Usually I would therefor put ...
I want to using solr for search on articles I have 3 table: Group (id , group name) ArticleBase (id, groupId, some other field) Article(id, articleBaseId, title, date, ...) in solr schema.xml file i just define all article field that mixed with ArticleBase table (for use one index on solr) like this: (id, articleBaseId, groupId, ...
Im working with a legacy database and an application written for Apple WebObjects and migrating that to Hibernate. I'm trying to map a many to one relationship and also its join attribute. But Hibernate gives "Repeated column in mapping" error if i try to do that, unless i make one of it readonly. But the application written in WebOb...
I want to store data which is dynamic in nature. The user can create forms for capturing data. The data can be stored in various formats as per the configuration. The major ones are a RDBMS and a XML file. XML file format is pretty easy to store dynamic data and load it back. I am not able to devise a data structure for a RDBMS. I curr...
In the Hibernate online documentation, under section 7.2.3 One-to-many, it's mentioned, that: unidirectional one-to-many association on a foreign key is an unusual case, and is not recommended. You should instead use a join table for this kind of association. I would like to know why? The only thing that comes to my mind is...
Can anybody tell me if usage of FireBird or PostgreSql can by used in a small e-mail payment or 1000 kiosk-terminal server's data management , which will mainly process very important financial data like balances, payment transactions ... ????? which open-source database server you will suggest in my case? I don't like MS SQL because it...
Oracle seems to have a reputation for being more scalable than other RDBMSes. After working with it a bit, I can say that it's more complex than other RDBMSes, but I haven't really seen anything that makes it more scalable than other RDBMSes. But then again, I haven't really worked on it in a whole lot of depth. What features does Ora...
EDIT: This is a duplicate I didn't find it at first. I am building a web-site for user-groups event management. Members : Name, Id Events : DateTime, Topic, OrganizerId (from FK to Members table) EventRegistrations : MemberId (FK), EventId (FK) Description (redundant) : A member can create and event, and becomes this event's or...
What Considerations do we need when creating a DB helper class in .Net? ...
i need to know the most popular dbms system which is available ...
What are primary keys used aside from identifying a unique column in a table? Couldn't this be done by simply using an autoincrement constraint on a column? I understand that PK and FK are used to relate different tables, but can't this be done by just using join? Basically what is the database doing to improve performance when joini...
What solutions exist to persist data, without requiring a full-blown enterprise server? I am fairly new to Java. At uni the whole curriculum was based on Java, so I coded a bit already. But it never went into depth with the available frameworks. The only way we actually touched on persistens was using "vanilla" JDBC connections. I've do...
What I have: A MySQL database running on Ubuntu that maintains a large table of articles (similar to wordpress). Need to relate a given article to another set of data. This set of data will be fairly large. There maybe various sets of data that will be related. The query: Is it better to contain these various large sets of data w...
This is a classic problem that I could never seem to come up with a solution for that I was happy with. What would be considered an OO-elegant and DB-scalable approach to this problem? Employee - Name, Phone, Meta, etc Company - Meta, etc - Employee[] CompanyRepository (RDMBS) - Company GetById(int) - Company[] GetAll() Approach #1...
I have a question on best practice for relational databases and hierarchies. My question is, is it more sane to use text or int (id) based hierarchies? I have a hierarchy, but it is not an id based one. The hierarchy is based on text e.g. 'level1', 'level2' as opposed to id1, id2 I use mysql and also solr for managing my data. At the ...