Cobol's File System Vs. RDBMs...
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From: Richard on 23 Jul 2008 19:09 On Jul 24, 9:49 am, softWare design <sabra...(a)baxglobal.com> wrote: > On Jul 23, 1:22 pm, Howard Brazee <how...(a)brazee.net> wrote: > > > > > I suspect most CoBOL developers work with mainframe & mini computers. > > In that case, they use the same file systems as everybody else. > > > So I infer that you find indexed file systems used by Windows based > > CoBOL programs to be less than robust. Those are where the file > > system had to be created by compiler makers to make up for Windows > > shortcomings. I haven't had experience with them - what are their > > lacks? > > Yes, I am referring to indexed file systems that are created by > compiler makers on Windows based networks (2k and XP). > They tend to get corrupted frequently for various reasons > especially when storing massive number of records. Then do not use Windows. Use a more reliable system. > They are also considered to be Closed systems. Accessing > them by external clients or customers would require creating > new programs to get into the data with the desired formats. Cobol has been able to access SQL databases for many years, some, such as Fujitsu, have SQL preprocessor included, for others you would use the preprocessor that comes with your database system. There are also products that give ODBC access to the Cobol files.
From: William M. Klein on 23 Jul 2008 19:15 The "external's" (how it works and how you specify it in the language) of COBOL formats (sequential, indexed, and relative) are specified in the ANSI/ISO Standards (and have been for decades). ORIGINALLY, most COBOL vendors worked in environments where these file systems were provided by the operations system (usually sold and developed by the same person as the hardware). When it comes to Unix (Linux) and Windows (previously DOS and OS/2), this is NOT true. There are some "independent" file systems (particularly for indexed files) such as Btrieve and C-ISAM. Most (possibly all?) COBOL compilers that work in such environments provide support for interfacing with those (indexed) file systems. I think (but am not positive) there are some that also allow for an RDBMS to be the "physical" system behind a COBOL indexed file system. HOWEVER, many *nix/Windows users WANT to use an indexed system that doesn't require any "add-on" product (indexed file system or RDBMS). For those users an "ANSI-conforming" (proprietary) Indexed system is provided by most (all?) vendors that operate in such environments. The "robustness" of those file systems are in direct relationship to how many PAYING customers demand/expect robust indexed file systems for their applications. MOST (certainly not all) COBOL applications that are now "developed" for production use on *nix/Windows use RDBMS for data storage. The robustness of such systems are, again, in direct relationship to how customers use them (and what they are will to pay for). -- Bill Klein wmklein <at> ix.netcom.com "softWare design" <sabraham(a)baxglobal.com> wrote in message news:bec7bcc3-f0ba-4db3-8a72-439c686373e5(a)m73g2000hsh.googlegroups.com... On Jul 23, 1:22 pm, Howard Brazee <how...(a)brazee.net> wrote: > > I suspect most CoBOL developers work with mainframe & mini computers. > In that case, they use the same file systems as everybody else. > > So I infer that you find indexed file systems used by Windows based > CoBOL programs to be less than robust. Those are where the file > system had to be created by compiler makers to make up for Windows > shortcomings. I haven't had experience with them - what are their > lacks? Yes, I am referring to indexed file systems that are created by compiler makers on Windows based networks (2k and XP). They tend to get corrupted frequently for various reasons especially when storing massive number of records. They are also considered to be Closed systems. Accessing them by external clients or customers would require creating new programs to get into the data with the desired formats.
From: HeyBub on 23 Jul 2008 19:23 softWare design wrote: > On Jul 23, 1:22 pm, Howard Brazee <how...(a)brazee.net> wrote: >> >> I suspect most CoBOL developers work with mainframe & mini computers. >> In that case, they use the same file systems as everybody else. >> >> So I infer that you find indexed file systems used by Windows based >> CoBOL programs to be less than robust. Those are where the file >> system had to be created by compiler makers to make up for Windows >> shortcomings. I haven't had experience with them - what are their >> lacks? > > > Yes, I am referring to indexed file systems that are created by > compiler makers on Windows based networks (2k and XP). > They tend to get corrupted frequently for various reasons > especially when storing massive number of records. > > They are also considered to be Closed systems. Accessing > them by external clients or customers would require creating > new programs to get into the data with the desired formats. The inability of external clients or customers to get into a file an muck about is a benefit, not a shortcoming.
From: Pete Dashwood on 23 Jul 2008 21:28 "softWare design" <sabraham(a)baxglobal.com> wrote in message news:bec7bcc3-f0ba-4db3-8a72-439c686373e5(a)m73g2000hsh.googlegroups.com... On Jul 23, 1:22 pm, Howard Brazee <how...(a)brazee.net> wrote: > > I suspect most CoBOL developers work with mainframe & mini computers. > In that case, they use the same file systems as everybody else. > > So I infer that you find indexed file systems used by Windows based > CoBOL programs to be less than robust. Those are where the file > system had to be created by compiler makers to make up for Windows > shortcomings. I haven't had experience with them - what are their > lacks? [Pete] That's a bit unfair, Howard. The COBOL file system on Windows desktops was not implemented to make up for Windows shortcomings, it was because you can't call it "COBOL" unless you provide these modules of the language. You might as well say that Indexed Sequential files on mainframes were invented because of shortcomings in the IBM OS. [/Pete] Yes, I am referring to indexed file systems that are created by compiler makers on Windows based networks (2k and XP). They tend to get corrupted frequently for various reasons especially when storing massive number of records. They are also considered to be Closed systems. Accessing them by external clients or customers would require creating new programs to get into the data with the desired formats. [Pete] There are some connotations to the word "closed" that can cause misunderstanding. I agree with you that the COBOL file system is "closed", inasmuch as you need to write a COBOL (or other) program which knows the structure of it, in order to access it. Certainly, some systems have ODBC drivers that permit access but the basic problem is that, unlike a DBMS, the structure of the data is not held in the file... (there is no metadata). This means that unless you can write a program or get one written, you can't access it. (Compare this with an RDBMS, for example, where anyone who knows SQL and has the right permissions can access the data.) When I first started using RDBMS with COBOL (early 1990s) I was amazed at how much better it was. Spread sheets could import and export data from the repository, with COBOL managing the grunt work. Unfortunately my excitement was not shared by people in CLC who saw open accessibility to data as undermining their authority as COBOL programmers. There were some heated exchanges until the landslide started and they were all overtaken by it. Today it is rare to see people pulling out the old chestnuts about performance and security of data (although we still get the occasional fossil who won't roll over :-)) (Don't take HeyBub's post seriously... he is winding you up... :-)) Nevertheless, as you can see from this thread, there are still people here who will argue that the COBOL file system is NOT closed. It really depends on what you mean by "closed"... As far as I'm concerned, if it requires special knowledge (like the structure of the data) to access it, and the system can't tell me that information, then it is closed. Here's a comparatively recent (3 years ago) discussion about exactly this: http://coding.derkeiler.com/Archive/Cobol/comp.lang.cobol/2005-06/msg00385.html As for Windows implementations of the COBOL file system being flaky, I've been using it for more than twenty years and have never experienced data corruption with either Fujitsu or MicroFocus implementations under Windows or DOS. But then, I've never used it to store 64 million records... :-) If proper regular housekeeping and reorganization is done, there is less likely to be trouble. It is certainly true that if programs abend, and proper cleanup is not instituted, there is a risk of data corruption. But that has ALWAYS been true on mainframes OR PCs. RDBMS automatically take care of this and that is one reason why they are perceived as more "stable". Pete. -- "I used to write COBOL...now I can do anything."
From: Robert on 23 Jul 2008 22:45
On Wed, 23 Jul 2008 14:49:13 -0700 (PDT), softWare design <sabraham(a)baxglobal.com> wrote: >On Jul 23, 1:22�pm, Howard Brazee <how...(a)brazee.net> wrote: >> >> I suspect most CoBOL developers work with mainframe & mini computers. >> In that case, they use the same file systems as everybody else. >> >> So I infer that you find indexed file systems used by Windows based >> CoBOL programs to be less than robust. � �Those are where the file >> system had to be created by compiler makers to make up for Windows >> shortcomings. � �I haven't had experience with them - what are their >> lacks? > > >Yes, I am referring to indexed file systems that are created by >compiler makers on Windows based networks (2k and XP). >They tend to get corrupted frequently for various reasons >especially when storing massive number of records. Most professionally developed Cobol systems abandoned indexed files and switched to databases, starting in the 1980s. The ones still using indexed files tend to be amateurs and small shops, who stayed with indexed because databases were expensive. That reason disappeared in the late 1990s when full-featured free databases such as PostgreSQL and MySQL became available. >They are also considered to be Closed systems. Accessing >them by external clients or customers would require creating >new programs to get into the data with the desired formats. There are ODBC drivers for proprietary Cobol file systems that allow any SQL tool to access the data. The drivers are not free. http://www.datamystic.com/datapipe/odbc_vendors.html There are free programs to translate a Cobol indexed file to CSV (comma delimited), which can easily be loaded to a database or spreadsheet. I posted the source for one here. It uses a copybook defining the Cobol file. http://groups.google.com/group/comp.lang.cobol/browse_thread/thread/dc52411acc35c5c0/41ceca276724555f?hl=en&lnk=gst&q=cob2csv#41ceca276724555f |