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What is Holding SAP-DB Back?
Derek Neighbors queries: "The current story about MySQL 4.0 has erupted into a Postgres vs. MySQL debate. We at GNU Enterprise, who have used about all Free and Propietary databases, would like to know why exactly people arent using SAP-DB? It clearly is on par with Oracle, is GPL and frankly has an awesome support team in SAP AG. There was a PG vs SAP-DB recently. Someone else mentioned that you can get CDROMs for free. So again the question is 'What exactly is hindering a wider acceptance of SAP-DB in Free/Open Software projects?'"
Another thing I forgot: sapdb is unhackable. If you ever wanted
to see what unmaintainable for normal people code looks like, go no further than to sapdb.
It is incredibly bloated and complex, very crufty internally, written in a weird pascal/C++ mix
with an SAP specific format for the files, has a build system that could be
only described as ununderstandable, no comments.
It is what you would expect from a 20+ years old codebase
I'm glad the SAP Berlin guys understand it (they seem to at least), but I see not much chance to do any changes
on your own. This makes it not very useful as a free software project.
Of course it is still nice that they offer it for free, but for all practical purposes it is like a binary only download. To be fair interbase has some of these problems too, but it has still relatively nicer source than sapdb. mysql is much better in this regard.
It is...
1. harder to install, with a slightly strange mix of admin tools (combination of old/crufty, and new/experimental)
2. definitely trickier to manage, as you need to learn protocols for setting up, and backing up, databases and their logs, at least. This is true of other RDBMSs of course, but the trend has been toward more self-managing systems.
3. Relies of ODBC as the cli--which is actually fine (eg, compatible with PHP) but still less familiar to Unix/OSS people
4. Still undergoing stabilizing bugfix cycle, seemingly, although I haven't myself ever encountered a problem with it
5. Is, as mentioned, less tolerant of inexpert admins--and more problematic, the error codes are frequently impossible to understand
6. Really is difficult, at present, to hack. In general, the code is VERY challenging to work with (particularly the ugly, custom built build system), although it should be said that the SAP internal developers are steadily improving all aspects of the system, and a time WILL come when external developers can see rewards for their hacking efforts.
Compensating for this is the VERY skilled and responsive SAPDB development team, and a very strong feature set.
Matt
Well, considering PostgreSQL is free, a whole lot less sorry for being picky, but it occurred to that some people might be lost in the irony.
PostgreSQL was never GPL'd. Not even copyleft, but just a plain free software license, can't remember if derived from BSD or MIT X. If one wants copyleft, SAPdb is the only choice now.
Leandro Guimarães Faria Corcete DUTRA
DA, DBA, SysAdmin, Data Modeller
GNU Project, Debian GNU/Lin
Becuase SAP DB doesn't support many of the critical features which are in the larger more respected database systems. The most important feature which is missing is transactions, ie: rollbacks, commits etc etc.
Umm, what are you talking about? Of course SAP DB (nee Adabas) has transactions; it's fully ACID, unlike, say, MySQL.
SAP DB is pretty much equivalent to Oracle 7.3.4 which is to say that it's a solid product for many real-world applications, but lacks many of the features for truly high-end deployment, like clustering, complex replication, guaranteed messaging, etc. I'd take Sapdb over MySQL any day, and probably over Postgres too. Another nice thing about SAP DB is that it can emulate Oracle's system tables, so an Oracle DBA can administer a SAP DB system very easily.
Also, SAP-DB doesn't have drivers for some of the more exotic tape systems, unlike DB2 or Oracle. The only tape system we could get working for backups with SAP-DB was an old single drive, manual loader DAT system.
Again, I'm not sure what you are talking about here. Do you mean you can't get an LSM plugin for SAP DB like you can for Oracle? Because that sort of stuff is really just fluff, you can do anything it can do with your regular storage manager (which may even be Legato) with a few simple scripts. I do agree that SAP DB's backup and recovery is primitive compared with Oracle's RMAN.
SAP-DB is pretty much the back end of SAP's commercial systems like SAP R/3.
It's a little more complex than that. SAP's R/3 product is an ERP system than competes with Oracle's ERP suite. For example, R/3 General Ledger competes with Oracle Financials. SAP were getting annoyed because every time they won a pitch against Oracle for ERP, Oracle ended up getting some money anyway, because R/3 required a database to run on, and Oracle was the most popular.
So, SAP bought ADABAS as tried to push ADABAS-D as the preferred database for R/3. That way, when they beat Oracle to win business, they would get all the business for themselves. Unfortuately, it never caught on, customers preferred Oracle, partly because it was a better product, and partly because they already had it and people who knew how to use it. So SAP were left with ADABAS-D which no-one wanted, so they renamed it to SAP DB to capitalize on their brand, and jumped on the Open Source bandwagon for some free publicity.
Q. If it's so great, why does SAP R/3 normally sit atop a different database, like Oracle or DB2?
A. R/3 was originally written for Oracle, so this is a tradition. Up until now, SAP DB hasn't been marketed actively by SAP as not to upset it's many database selling partners. Newer applications are now developed for SAP DB first.
Q. SAP-DB is 20 years old. It has an unmaintainable code base. It is bloated and complex, very crufty internally and written in a weird pascal/C++ mix witha SAP specific format for the files and an uncomprehensible build system.
A. I prefer the word challenging. Parts of it are of course constantly rewritten, so I don't think a single part is actually 20 years old. And I object aliasing '!= make' with 'incomprehensible'. The concepts are actually pretty close to newer build systems like ant. Without it, the criticism would simply read that the make files are incomprehensible.
Q. SAP-DB needs a lot of effort to set up and create a database, sometimes even worse than the magic juju you need to go through with Oracle.
A. Not really true, especially not for a production database. But the entry level documentation could be made better by describing when and how to keep things simple.
Q. Oracle does replication and hot standby. SAP-DB doesn't. These are pretty important features in the enterprise.
A. Replication is not on our agenda (despite the oddly named Replication Manager). Hot standby is currently being implemented.
Q. Not in BSD Ports tree. Probably also goes for Linux, (but the argument there would probably be more "doesn't comes (integrated) with the distribution" If something gets included with distributions, it spreads much faster.
A. True. But our main job is to supply SAP DB for SAP customers. Anything else has to be done by others interested in SAP DB.
Q. harder to install, with a slightly strange mix of admin tools (combination of old/crufty, and new/experimental)
A. Partly a documentation problem. There isn't actually a mix of old and new admin tools. There is a command based API, which is accessible from various programming languages, and there are tools which are implemented on top of this API.
Q. definitely trickier to manage, as you need to learn protocols for setting up, and backing up, databases and their logs, at least. This is true of other RDBMSs of course, but the trend has been toward more self-managing systems.
A. SAP DB is mostly self managing. Some of the tasks were it isn't have severe performance implications (like distribution of data volumes over disks) so simply picking a default is questionable at best.
Q. Relies of ODBC as the cli--which is actually fine (eg, compatible with PHP) but still less familiar to Unix/OSS people
A. There is no standard database API for Unix. But of course anything would be better than a Microsoft API.
Q. Still undergoing stabilizing bugfix cycle, seemingly, although I haven't myself ever encountered a problem with it
A. Insert lame joke about Linux 2.4.
Q. Is, as mentioned, less tolerant of inexpert admins--and more problematic, the error codes are frequently impossible to understand
A. We should probably supply a tool which makes information about the error codes easily accessible from the command line.
Q. Really is difficult, at present, to hack. In general, the code is VERY challenging to work with (particularly the ugly, custom built build system), although it should be said that the SAP internal developers are steadily improving all aspects of the system, and a time WILL come when external developers can see rewards for their hacking efforts.
A. True. Although I still object to the notion that make was presented to mankind on the mount Sinai.
Q. Does SAP have anything close to Oracle's RMAN?
A. SAP DB logs all backups. The DBMGUI can use this log to automate tasks like 'restore from this full backup to this timestamp'. This works also with external backup tools.
Q. Sect Where's the O'Reilly book on SAP-DB?
A. It took some time for PostgreSQL to get books so I guess a SAP DB book is still a year or two away.
Q. Does it have Multi Concurrency Version Control (MVCC)?
A. It is implemented in the undocumented object database part. There are plans to make this also available to the relational database part, but a release date has not been set.
Q. Are there any Free Software success stories of projects using SAP-DB?
A. So far, SAP DB seems to appeal mostly to commercial software vendors for whom Oracle or MS licenses are too expensive/bothersome.
Q. Are there better admin tools?
A. No. Or not yet. But the administration is easily scriptable, so most common tasks can be reduced to a single command.