If your data can be modelled into tables a relational database, especially a lightweight one like SQLite, using DBI with DBD::SQLite, would probably be a good fit.

Thanks for the reply...

The quick answer is that we don't have access to a relational database for this project, unfortunately. However, thanks for the SQLite recommendation - I'd not heard of it before.

Thanks again,
MatthewFrancis

we don't have access to a relational database for this project

If you can install Perl modules than you can install SQLite. It comes bundled with DBD::SQLite. It is a simple C library, and the DB is a single file. Which means no daemon running, no port to open, no admin to do (access rights are the access rights to the file). From an admin point of view it is just like a flat file. Using it is (or at least should ;--) really be a low-level implementation decision.

Fitting arbitrary complex data into a relational data may be hard. Very hard. Using MLDBM or similar (DBM::Deep looks interesting) is much easier. To the original questioner: are you using DB_File or GDBM_File as the database backend? The default SDBM_File has many drawbacks (limited record size, missing EXISTS is implemented only since 5.6.1).

Thanks for the reply,

I'm using things as follows:

use SDBM_File;
use MLDBM qw ( SDBM_File );
[download]

Again, I'm a total newbie to DBM issues, so if there are better ways to to this I'd be grateful for some pointers.
Thanks!!
MatthewFrancis

Hi,
Thanks for the response. The following works w/ the tie-statement commented out (as below):

      2 use SDBM_File;
      3 use MLDBM qw (SDBM_File);
      4 use Fcntl;
      5
      6 #tie (%h, 'MLDBM', 'dbm_file', O_CREAT|O_RDWR, 0666) || die "c
+ouldnt open tie-file\n";
      7
      8 $h{ "1" } = { "a" => "first" };
      9 $h{ "2" } = { "a" => "second" };
     10 $h{ "3" } = { "a" => "third" };
     11
     12 foreach ( keys %h )
     13 {
     14     $value = ${ $h{ $_ } }{ "a" };
     15     print "key: .$_. value: .$value.\n";
     16 };
     17 
     18 if ( exists $h{ "1" } )
     19 {   
     20     $h{ "1" } = [ "a", "b", "c" ];
     21     
     22     foreach ( @{ $h{ "1" } } )
     23     {   
     24         print "value is: .$_.\n";
     25     };
     26 };
[download]

I get:

key: .1. value: .first.
key: .2. value: .second.
key: .3. value: .third.
value is: .a.
value is: .b.
value is: .c.
[download]

but, if I uncomment the tie, I get:

key: .1. value: .first.
key: .2. value: .second.
key: .3. value: .third.
SDBM_File doesn't define an EXISTS method at dbm.pl line 18
[download]

Any help appreciated. I'm using MLDBM because, per literature I encountered, regular DBM doesn't permit complex data-structures.
Thanks again -
MatthewFrancis

You could just use defined() in this case, but exists() does work on most dbm implementations. Instead of SDBM_File, try DB_File, GDBM_File, or NDBM_File.

DBD::DBM can work with BerkeleyDB and MLDBM and both of those are also handy on their own. See also the pod for AnyDBM_File for a brief comparison of different DBM types.