Slashdot Mirror
Converting From Oracle To DB2?
Peter asls: "We are currently running Oracle 8.1.5 on Sun SPARC Solaris 2.6 for our applications (written in C, C++, and JAVA. Because of the high costs of Oracle we are considering a full scale conversion to DB2. Does anyone know how involved this task would be and to what extent would this affect the code in such a conversion. Any information on this would be greatly appreciated."
Agreed!
To quote my flatmate (hp-ux sys-admin) when I just read the article to him - "fuck!"
This really depends on how much code you have, how much data you have etc. etc. Has anyone done a keeping oracle cost vs a conversion cost? Don't forget that converting will run over time and budget (of course :)
Seriously, this isn't a minor plug-in a new backend sort of thing. DB2 is different with administration and the dialect of SQL is a bit different.
:)
Overall the level of industry use/acceptance of DB2 is much lower than Oracle, particularly the Unix/NT (UDB) version of DB2. DB2 is big in the mainframe world, but good luck finding new hires with DB2 on Unix experience. Mainframe experience doesn't automatically port over to Unix experience.
Cost is going to vary widely based on:
1. Who's doing it? -- In house or hire consultants? Consultants will cost a lot more, but might be able to pull it off faster.
2. Level of in-house expertise with Oracle and DB2 (doesn't sound like much since you're asking this)
3. Timeframe, both for deploying the new database, and schedule for supporting both at the same time.
4. Training you plan to offer to existing people and/or new people you'll be hiring.
5. Level of buy-in from the technical and business users -- if the techs hate db2 the project will be an expensive failure. If the business users won't let up on change requests during the conversion then the project will likely be late and/or over budget.
6. Complexity of what you're trying to port to DB2 and the level of reliance on proprietary Oracle features.
Why are you asking Slashdot this? Seems like you should be asking us about a conversion to mySQL or PostgresSQL...
"But actually trying to use m4 as a general-purpose langage would be deeply perverse" --ESR
Seriously, this isn't a minor plug-in a new backend sort of thing. DB2 is different with administration and the dialect of SQL is a bit different.
The fringes of the SQL may be different but the core SQL language is controlled by the SQL Language Council so any SQL which comes under the SQL '92 spec should move across without difficulty. It's the extras that cause the problems where the different vendors have different approaches to various problems.
Overall the level of industry use/acceptance of DB2 is much lower than Oracle, particularly the Unix/NT (UDB) version of DB2. DB2 is big in the mainframe world, but good luck finding new hires with DB2 on Unix experience. Mainframe experience doesn't automatically port over to Unix experience.
I'd like to know where you get your figures from. The level of industry use of DB2 is not 'much lower than Oracle', despite what Oracle's marketing department would have you believe. All those ads which say '96% of the Fortune 50 use Oracle' miss out the fact that most (all?) of the Fortune 50 use DB2. Most major companies use multiple database systems for various reasons. And an increasing proportion of those DB2 users are using UDB.
Cheers,
Toby Haynes
DB2 UDB developer
Anything I post is strictly my own thoughts and doesn't necessarily have anything to do with the opinions of IBM.
Have you ever done this ?
Quite obviously not.
I forwarded this article to my DBA, only to find out *he* posted it
ROFL !
How big is this thing ? The trouble with a DB2 port, compared to an Oracle -> SQL Server port, is that it really is quite different internally. A good Oracle data model looks a lot like a good SQL Server data model, and both subset quite trivially onto a MySQL data model (which isn't good, but it's the best you'll get).
DB2, OTOH, will suck performance-wise, unless it's re-designed and tweaked by someone dressed in a white shirt and a dark suit. It's a whole different bucket of cod, and you need to grok IBM to get far with it.
If it's a little thing, then you can live with the lumps. If it's a biggie, then you need help to do the tweaking. Last time I looked (early '99) IBM were pretty clued up on being helpful with this.
The SQL dialects are about as equivalent as English and Welsh.