Storing data in a relational database is natural because it is more like the way we store data in our minds than the hierchical structures of traditional file systems.
You'd be surprised how few actually think in predicate logic. Or any kind of logic.
Java has the.setAccessible methods that allow access to private members via reflection. These methods are subject to the security context, so they probably won't work in applets. And of course information about private members can be extracted by tools that are freely available from well known cracker sites like java.sun.com.
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.
R/3 was originally developed for Oracle only, which accounts for them having the vast majority of installations. No, it's not Oracle and DB2, it's Oracle and a bunch of wannabes (OK, I'm exaggerating).
SAP DB is not swapped out for Oracle, the customer buys SAP software with the database of his choice from the start.
Customers pay for the database as a certain percentage of SAP licences (different for each supported database), but it's paid to SAP. So it may appear to technically inclined people that the database is for free.
SAP bought SAP DB (then Adabas D) to be able to offload some processing to a different server without requiring additional database licenses.
SAP bought SAP DB to be able to implement some non relational DB processing without being locked into a specific vendor.
SAP DB has never been actively marketed because SAP didn't want to appear as a competitor to IBM or Microsoft.
The Pascal sources are translated to C and then compiled using the local C compiler. That's (among other things) why you'll need to install the development tools.
File with names like [vg][a-z][a-z][0-9]+ are Pascal sources.
Slashdot Mirror
What you want is a web site where users edit normal pages and upload them through ftp or WebDAV (which is integrated into many HTML editors).
See also WhyWikiWorks
You should also think about viewing diffs of page versions, which is awful in XHTML (and most Wikis have a nice WYSIWYG diff).
Storing data in a relational database is natural because it is more like the way we store data in our minds than the hierchical structures of traditional file systems.
You'd be surprised how few actually think in predicate logic. Or any kind of logic.
If you want to invest some money under your scheme, do you
- create a new product? (high risk, low payback, because everyone else can copy your idea quickly)
- wait for someone else to create a new market and copy it (low risk, low payback)
It just doesn't sound right to charge for things that don't work (support) and not for what does work (software).
Java has the .setAccessible methods that allow access to private members via reflection. These methods are subject to the security context, so they probably won't work in applets. And of course information about private members can be extracted by tools that are freely available from well known cracker sites like java.sun.com.
No Java programmer who read that believes you.
Why not? They seem pretty gullible otherwise.
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.
SAP DB is not swapped out for Oracle, the customer buys SAP software with the database of his choice from the start.
Customers pay for the database as a certain percentage of SAP licences (different for each supported database), but it's paid to SAP. So it may appear to technically inclined people that the database is for free.
SAP bought SAP DB (then Adabas D) to be able to offload some processing to a different server without requiring additional database licenses.
SAP bought SAP DB to be able to implement some non relational DB processing without being locked into a specific vendor.
SAP DB has never been actively marketed because SAP didn't want to appear as a competitor to IBM or Microsoft.
File with names like [vg][a-z][a-z][0-9]+ are Pascal sources.