Update, RDB, a Relational Database Manager 
Author Message
 Update, RDB, a Relational Database Manager

For all those of you who liked 'RDB' before I have just posted a new
version of the 'RDB' system. It can be accessed via anonymous FTP to
rand.org.  Location is: pub/RDB.tar.Z.

For those who missed my note last July (and might be interested in RDB)
the first part of the note it is attached.

Summary of changes:
    Major modifications:   etbl, ptbl, reporttbl
    Some modifications:    repair, valid
    New:                   rdb, lst2tbl, tbl2lst
    Little or no changes:  column, compute, headchg, jointbl, mktbl, row,
                           sorttbl, summ

A few details about the changes:

The edit operator 'etbl' now handles big data fields, i.e. data fields that
are longer than the terminal width (or really big, like 4000 chars or so).
This is accomplished via a new option '-list' which produces a file to edit
with the data in 'list mode', where the column names are on the left and the
data values are on the right.  This way, the long data values stay on the
screen, although you don't get many entries ("rows") on the screen if the
data values are very large.

Etbl also now handles big datafiles, i.e. files larger than one would normally
edit directly (say 2 to 100 Mega-Bytes). This is done by specifying groups of
lines, by number, to edit. Only the selected lines are put into the file to
edit, and then merged back into the original file (actually the copy) after the
editing is complete.  One can still specify one or more columns to edit, and
now both options can be used together, to edit "rectangles" of the datafile
if desired. Please note the WARNING in the '-help' listing though.

The print operator 'ptbl' has had the '-PX' option changed to do more when
printing is wanted; it now sets both page and line sizes for several common
font sizes, for standard and rotated pages. When not printing, the default
page size is based on the current terminal or window size. Actually
the defaault number of lines is terminal size minus one, so a pager like
'less' can be used conveniently (the header will stay on the top line
on all pages).

This operator now uses 'printf' in an eval for a significant performance
improvement.  Also a '-B' option for big data fields was necessary, as 'printf'
does have some limits, unlike perl.  The definition of the '-truncate' option
changed slightly.

The arbitrary style report producer, 'reporttbl' has been modified to handle
big data fields. If the associated 'form' file contains a picture field
starting with the '^' char, then code is eval-ed to print the entire data

tough).

Operators 'repair' and 'valid' have less grand changes. 'Repair' now works on
existing RDB datafiles, and 'valid' now has a '-size' option. The latter
will show header template information, along with the max size of data in each
column.

The program 'rdb' is an RDB shell that I haven't used much but was of some
interest at one time. I may do more with it later.

The operators 'lst2tbl', and 'tbl2lst' are mostly for use by 'etbl'.

All operators still take a '-help' argument which will show online the
details necessary (I hope).

If there are questions or problems please email me directly.
Feedback is encouraged.  I will be updating the code more as I have time.

Walt Hobbs

....................................................................
Original message:

Another DBMS? Why?

Well, we have found it very helpful for the following reasons:

1. EASY to use, straight forward in concept.
2. Highly portable datafiles, e.g. to/from Mac/PC spreadsheets.
3. The operators run on any UNIX machine (that has PERL).
4. Operates on intermediate datafiles, which will later be entered into
   a major, do-it-all-for-everybody-dbms such as Ingres.
5. No arbitrary limits, can work where Ingres (sometimes) can't.

... (the rest of the info is available in the posting).



Sun, 20 Mar 1994 07:07:40 GMT  
 
 [ 1 post ] 

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