Hi, I`ve read that columns that are chosen for indices should discrimate well among the rows, i.e. index columns should not contain a large number of rows with the same value. This would suggest that booleans or an enum such as gender would be a bad choice for an index. But say I want to find users by gender and in my particular datab...
The subject says it all... ...
One of the appropriate uses for sqlite3 is "in-memory databases". This sounds like a really useful tool for my C++ applications. Does anyone have an example of how this is done in C or C++? I'm specifically looking for a canonical way to slurp several flat-files into an in-memory database, then do some joins. ...
I am looking for database-caching framework for C++ providing the following: Generate object/table representations via some pseudo-language (macros/templates) Retrieve objects from DB by key when needed LRU caching Immediate and delayed update of DB on object update (via getter/setter methods) ...
Currently we're using hand-rolled SQL in Data-Access objects and a lot of stored-procedures and triggers which amount to around 20k lines of code. We're finding that simple changes are causing a couple of days' work to fix, and its causing deadlines to slip. Changes include modifications to tables to cope with additional data, general r...
I’d like a visual database tool that will allow me to access multiple database types from the same program. I’m looking for anything that supports Mysql, PostgreSQL, and Derby. Anything else it supports is a bonus. ...
I have an Informix SQL query which returns a set of rows. It was slightly modified for the new version of the site we've been working on and our QA noticed that the new version returns different results. After investigation we've found that the only difference between two queries were in the number of fields returned. FROM, WHERE and OR...
I am using LLBL Gen Pro v2.6 and am attempting to create a means of auditing changes made to the database. Now, I know that LLBL Gen has auditing built into it using AuditorBase and dependency injection. The question I have is; I need to track not only the stuff that LLBL Gen exposes as auditable, but also the User who made the changes. ...
Hi there, I'm putting together a small web app that writes to a database (Perl CGI & MySQL). The CGI script takes some info from a form and writes it to a database. I notice, however, that if I hit 'Reload' or 'Back' on the web browser, it'll write the data to the database again. I don't want this. What is the best way to protect ag...
Does ODBC support asynchronous calls? If it does, then can you tell me about any reference materials? My preferred language is C++. ...
Hi all, how can i import data from an oracle database to a mysql database by using CTL file (generate with Toad for oracle)? Thank in advance Andrea ...
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...
Premise: The requirements for an upcoming project include the fact that no one except for authorized users have access to certain data. This is usually fine, but this circumstance is not usual. The requirements state that there be no way for even the programmer or any other IT employee be able to access this information. (They want me to...
What's the general consensus? If you need to change the database after a given action, do you use an observer pattern and let the framework / application handle the update for you? Or do you bypass the application and delegate the update to a database trigger? Obviously the trigger is faster, but is it worth it? ...
How would make a news feed "friendly" database design, so that it wouldn't be extremely expensive to get all of the items (query) to put in the news feed? The only way I can think of would involve UNIONing nearly every table (representing groups, notes, friends, etc) and getting the dates and such, that just seems like it'd be a really ...
I once read about an open source database for postal codes with geolocation data but now I can't remember its name. Can someone help? ...
What is the proper way to split up SQL statements to send to an Oracle ADO.NET client? For instance, lets say you have the following code in a text file and want to execute these statements: CREATE TABLE foo (bar VARCHAR2(100)); INSERT INTO foo (bar) VALUES('one'); INSERT INTO foo (bar) VALUES('two'); I believe trying to send all tho...
How do I force Postgres to use an index when it would otherwise insist on doing a sequential scan? ...
A quick search gave me this announcement of Parrot DBDI from January 2004 and a dbdi-dev mailing list which appears to be long dead. Is Parrot DBDI still being developed? Is anyone working on a different database API or interface for Parrot? ...
I am developing a cocoa application that will be making heavy use of both web services and a standard dbms (most likely MySQL) and I am wondering if anyone has a good option for a database library or ORM solution they have used. CoreData is not an option due to the need to support a standard DBMS and to be able to modify the data outsid...