I came across this question after searching for a ODBC or JDBC. To my surprise, since I am new to db4o I found there are tools to browse db4o, including a Netbeans and Eclipse plug in. However, when it comes to the question at hand, I only found one company, and the product is not being sold nor demoed (makes me think is not ready yet).
So, how do you transfer data? Is there a tool or script I have not found yet?
That's right. When it comes to db4o's dRS, in order to move your data to a relational database you need to define a Hibernate mapping. But it's definitely the way to go for this kind of migration if you don't want to do it all by yourself.
Best!
Data transfer between db4o and relational Databases (in both direction) can be easily done with db4o's tool: dRS - db4o Replication System (based on Hibernate).
BTW, db4o user forum might be very useful, you will get answers directly from core developers.
In my opinion, this comes down to the Object-relational impedance mismatch. Which is to say, except in very simple cases, there isn't necessarily a direct translation from a database row to an object. Your object model is fundamentally different than your database schema. Therefore, I would imagine that in most cases, you will have to come up with the mapping (and a migration application) yourself.
This goes generally for any relational database/object database, not just SQL Server and db4o.
Related
I have bought a Oracle 11g recently and I wanted all my developers to use it. Obviously I can't buy different licenses for each. So is it possible for me to create one database for each of the developers?. By inference I know it is possible.
However, I couldn't find how I can do it. I googled. There was no definite guide for this particular case. Can you point to the right resource?
Or could you list down the steps to achieve this?
I would ever be grateful.
-
Sheldon
When you create a user in Oracle, you're creating a schema. A schema is a collection of tables and related objects (views, functions, stored procedures, etc) specific to that schema. So each developer could have their own user/schema, and work independently of one another. Access to other users can be granted, and public synonyms can be created to ensure that YOUR_TABLE points to a YOUR_TABLE in a specific schema, without the need to specify that schema. But this can eat space...
If there is shared development, might be best to have a single schema so everyone is working on the same copy.
Create one database and give each developer it's own schema (username/password).
As long as all your database instances are on the same server you can build as many as you want without paying any more. Performance might become an issue with more instances depending on how heavily used they are.
You don't mention your platform.
On windows, here's how to use the Database Configuration Assistant (DBCA). I think it's pretty similar on *nix as well.
Each database so created has a different name. To access them it's simply a matter of using a tnsnames.ora file with different entries for each instance on the server.
You can buy Oracle personal edition for each developer and install it on their desktop/laptop. According to shop.oracle.com it's $460 per user. This way you can give everyone full access to Oracle and save a lot of trouble. Developers can learn Oracle more quickly and be more productive, and DBAs won't have to worry about them bringing down the server.
Or possibly you could even use it for free if your program is not in production yet. The Oracle Developer license lets you:
... use the Programs, subject to the restrictions stated in this
Agreement, only for the purpose of developing, testing, prototyping,
and demonstrating Your application and only as long as Your
application has not been used for any data processing, business,
commercial, or production purposes, and not for any other purpose.
Our IT manager is asking my help on deciding on which would be the best to save the data. Is it in sharepoint or sql server.
On my side I don't know much about saving data on sharepoint server, how does it work, how fast, how secured, etc. I even have a doubt if sharepoint is capable of complex database design. As far as I know, sharepoint is not a database server that's why I have this doubts.
So obviously I would say Sql Server would be my prefered storage and also because Sql server is known to me for a long time already. Considering my 3 weeks exposure on sharepoint vs. 7 years on Sql Server. I don't have the enough experience to witness the strength of Sharepoint for me to decide on what to do. So to be fair on sharepoint I would like to ask you guys out there who are more experienced on this.
My questions:
1.) Does sharepoint have the ability to store data?
2.) If sharepoint can store data, what are the pros and cons?
3.) Can it cover a complex design such as relational database design like sql server does?
4.) If you where to develop a sharepoint project, would you choose sql server as the backend?
Thanks in advance!
It obviously depends on the application, and complexity of it, who the client or audience is, and how you want to deploy it.
Here are my answers to your questions:
1. Yes
2. Pros:
It provides a UI for updating data.
Cons:
Creating relational structures will be complicated.
Think custom lookup lists, associated with other custom lists.
3. Yes, but I wouldn't try it.
4. SQL Server, but this depends on the project and
isn't an entirely technical decision.
Personally, I think given your skillset, you should use SQL Server, if your manager has said it's up to you.
SharePoint itself is built on top SQL Server and ASP.NET.
Yes. You can create a custom list (basically similar to table structure), you can store document along with its metadata. You can store web pages if you are using it as your publishing (CMS) platform.
It's not supposed be a relational engine like SQL Server. Pro: versioning, workflow, for most cases, UI is there to support data input / editing. Con: Limitation of the UI w/ large amount of data.
To some degree you can relate one list to another field in a different list / document metadata.
See what I said before point 1.
SharePoint offers its own database layer built on top of SQL Server.
A complex object model is provided, and the SQL language API not available.
Acsess is by API, REST, and UI List Webparts with views; NOT SQL and the database is not accessible except through interfaces.
Deep inside data stored in Entity-Attribute-Value triples (specifically: site, web, list, item, state, field, value) such that each value goes into its own record. This is strickly non-tablular.
Maintains a dynamic end-user populated Metadata dictionary.
As a non-relational layer above a DB is offers inheritance, multi-type list, hierarchies, taxonomies, versioning, check in/out and other advanced features missing from a relational model.
Documents may be attached to a list.
Extensive use of GUIDS for identifiers, but this causes problems when moving partial related data between systems.
No referential integrity.
No joining of database tables or lists.
Filtering is more limited than in SQL.
No concept of a schema.
Parts of SharePoint break when restoring from a backup or when published to a separate site.
Rolling new features and data from development to production is problematic and sometimes breaks.
Hope this helps.
Sharepoint is obviously not a Database Server but somehow it works on some ways.
1.)Yes
2.)You can but not as complicated as Sql Server does.
Pros: It's the interfaces the gives sharepoint the edge, UI grants the user a friendlier way of inputting data.
Cons:Just like what I've said complicated database design is not easy to do.
3.) 100% Yes
4.) I would prefer Sharepoint if the application doesn't need complex design on data. Definitely Sql Server for enterprise type of application.
I want to store code similar to how jsfiddle stores code. I currently use Postgres for my main database but I'm wondering if it's more ideal to be using a NoSQL database?
Code snippets for now will have just one author, but in the future there may be multiple authors and I want the ability for reverting as well.
I know there are key/value databases and document-oriented databases. Which specific noSQL db would suite my needs? Or should I still stick with my Postgres db?
FYI:
I'm using django
The users will be permanently stored in postgres ( I'm using openID )
You can't choose a non-relational data strategy without defining what you want to do with your data.
Relational database design comes from rules of normalization, which you can apply once you know your data alone. But non-relational database design depends on your queries more than your data.
But without knowing anything about your application, my first recommendation would be to stick with PostgreSQL. Store your code snippets in text blobs, and meta-data about the code (authorship, date, language, project, etc.) in additional columns alongside the text blob. Also you can consider using GIST indexes to allow for flexible searching.
You might also consider Apache Solr, which is technically similar to a document-oriented DBMS, though it is usually presented as a fulltext search engine.
As for NoSQL databases, the only ones I'm familiar with are XML (doesn't scale well and has bad concurrency), and local databases such as Paradox, dBase, FoxProx and Access. I would not recommend any of these.
I think that the idea that it's a NoSQL database should be a smaller factor in your decision. Consider these things instead.
Redundancy. Can you run it on two servers at the same time or does it support failover? (SQL Server, Interbase, Firebird)
Concurrency. Will you host this app on the web? How will it handle 10 concurrent operations? (PostGres, MySql, Interbase, Firebird)
Speed. How long is acceptable for a lookup or post?
Embeddability. Is this a desktop application? An embedded database can make things easier. (Local databases such as Paradox, dBase, FoxPro, Access, Interbase, Firebird or SQLite)
Portability. Desktop apps may run on Mac, Linux, Windows. (SQLite)
Sounds like a relatively uncomplicated application which could be implemented in a traditional relational database or a NoSQL without too many problems.
However if you're keeping the userbase info in PostgreSQL, it would seem simplest to just stick with that as a single storage method. Using both an SQL database and a NoSQL adds complexity, makes joining across the datasets hard (so eg. you couldn't make a query to do something like ‘list users along with their most recent document’), and makes it impossible to ensure consistency between the two datasets.
What do you get for this trouble? You want versioning. CouchDB will give you revision control, but it's questionable whether you should be using that for UI-level versioning (eg because compacting the database will lose your old versions).
I have been working on VB6 database desktop programming, but now a client is asking for a
simple web interface (some inserts into SQL Server db used by a desktop application).
The question is: Which approach is better?
1)creating asp.net project, connected directly to the SQL Server database;
2)creating separate (simple) mysql database managed by php and synchronization (in 15 minutes for example)
Thanks.
Personally since you already have the SQL Server database, I see no reason whatsoever to add the complexity of another database and then synchonization. The first alternative is simpler to create and can be secure if you design it correctly. The issue about hosting is irrelevant since you are going to your own database that already exists, so is the issue about cost since the databse is already there. Further since you are already supporting SQL Server, you may be able to reuse some code rather than write new code (mysql's version of SQL is not the same as SQl Server's version). Synching the two databases may be more complex than you think (differnt data types, etc.) and the data in the real database is not real-time whereas with the first alternative it is.
I'd prefer the separate database approach.
It's more secure.
PHP/Mysql hosting is widespread
You can pretty much achieve anything with the technologies available, it just depends on your skill and productivity with specific technologies and the availability of online help. Plus Microsoft stuff you tend to have to pay for whereas PHP/MySQL is totally free.
I was probing around a bit in the realm of databases and hit the notion of having heterogeneous databases. I googled and found this - link text
My question is what kind of scenario would put this into practice and is it really useful? Is it just another thing which was thought about but not implemented or in case it was implemented, then it got restricted to a very niche area?
cheers
I would say yes, very much so. One implementation I am familiar with is integrating MAS90 with an LOB production system. The data is duplicated in both but accessed and used in different ways.
I've worked on a heterogeneous system before. It's a commercial system to manage study abroad programs for large universities, and they had installations on Oracle, MySql, and Sql Server. I was an outside consultant handling a very specific conversion project, though, so I didn't get to see many of the issues involved in making it work well everywhere.
I do remember that the single biggest hurdle I had to deal with was Oracle's lack of a simple autoincrement-style column and having to set up separate sequences instead. There were a number of datatype mismatches as well, but there was a pretty good system in place to just map those.
Note that even here, each customer only had one kind of database. We didn't have to worry about replicating data itself between db types (aside from a few common lookup tables). Just structure.
Different departments in your company might use different databases. I pull data in and push data to from the following
SQL Server
Oracle
Sybase IQ
Access
MySQL
FoxPro
Flat files
Excel files
The SQL Server database is the repository off all the data but it pull from many different databases to populate data and then data will be pushed to different databases for departmental use