Best Database selection for Client/Server Application (Multiuser) with Delphi?

i want to code a software with Delphi XE, that will be able to connect to a server and users should be able to read/write the database.

All records will be string (unicode enabled), maybe small amount of it can be blob.

My needs are;

• Multiple users enabled
• More than one user should be able add new records at one time
• Capable of storing huge amount of data
• Users can be able to edit their own records
• Un开发者_如何学Goicode enabled
• As possible as low cost solution

Thanks right now...

I vote for Firebird. It fits all your needs and it is free.

I would go with postgres - it's also free and is very fast.

Sandeep

Most of your requirements are handled by most modern database engines (althout concurrency management is not exactly the same among all databases). But to choose the database(s) that would suit you best you should give more precise informations:

• "Multiple users". How many concurrent connections? 10? 100? 1000? 10000? 100000? More?
• "More than one user should be able add new records at one time". How many inserts per hour? Is this an OLTP database, or a DW one?
• "Capable of storing huge amount of data". How many tables? How many rows? How many fields? What's the average row size? Do you need LOB support? How many indexes?
• "Users can be able to edit their own records". How often? How many? How long? Some databases have better locking mechanism than others.
• "Unicode enabled". Which flavour? UTF-8? UTF-16?
• "All records will be string". Which is the maximum string length you need? Hope they are "natural" string fields - storing non-natural string data in string fields usually lower performance.

I'm sure you'll get others, but ElevateDB fits your needs.
It's the follow-on to DBISAM, which does NOT have Unicode support. But ElevateDB does.

May I suggest to take a look at NexusDB. It also fits all your needs. Bill Todd has just reviewed the product.

"Users can be able to edit their own records" What does it mean for you? A database in which records are not editable, that is a Read/Only database, is not very common.

You'll have to think about the general architecture of your software. You just don't select a database like a new car. I'd suggest that you won't be focused on the database choice, but take a look at the whole picture.

Here are some advices:

1. Separate your database storage, the User Interface, and your software logic. This is called 3-Tier, and is definitively a good idea if you're starting a new project in 2010. It will save you a lot of time in the future. We use such an architecture in our http://blog.synopse.info/category/Open-Source-Projects/SQLite3-Framework

2. Use a database connection which is not fixed to one database engine. Delphi comes with DBX, and there are free or not so expensive alternatives around. See http://edn.embarcadero.com/article/39500 for dbx and http://www.torry.net/pages.php?id=552 for alternatives

3. Think about the future: try to guess what will be the features of your application after some time, and try to be ready to implement them in your today's architecture choices.

In all cases, you're right asking for advice and feedback. The time you're spending now before coding will spare your time during future maintenance.

For example, if one of your request is that "All records will be string", with some BLOB, your database size won't never be bigger than a few GB. SQLite3 could be enough for you, and there is no size limitation in the TEXT fields in this database.

Nobody's mentioned SQL Server Express so I guess I'll do it...
Microsoft SQL Server Express is jolly good and is also free.
Yes, it does have limits but they're pretty big and it's not possible to know if they're sufficient without further info from the OP.

• Multiple users enabled - yep
• More than one user should be able add new records at one time - yep
• Capable of storing huge amount of data - depends on definition of huge. But "probably"
  
• Users can be able to edit their own records - umm, yes
  
• Unicode enabled - yep
  
• As possible as low cost solution - it's free. But the data access components will depend on your choice of access method