Re: Implemented idea, feedback needed/welcome

On Wed, 4 Aug 2010 19:50:36 +0200, Jens Rehsack
<[email protected]> wrote:

> 2010/8/4 H.Merijn Brand <[email protected]>:
> > http://www.xs4all.nl/~hmbrand/TD.tgz

New version available as http://www.xs4all.nl/~hmbrand/Tie-DBD-0.01.tgz
t/10_hash.t still has to be changed

> >
> >    use DBI;
> >    use Tie::DBD;
> >
> >    my $dbh = DBI->connect ("dbi:Pg:", ...);
> >
> >    tie my %hash, "Tie::DBD", $dbh;
> >    tie my %hash, "Tie::DBD", $dbh, "foo";
> >
> >    $hash{key} = $value;  # INSERT
> >    $hash{key} = 3;       # UPDATE
> >    delete $hash{key};    # DELETE
> >    $value = $hash{key};  # SELECT
> >
> > Please edit t/10_hash.t to do what you need to do to connect to Postgres
> > or Oracle. Support for MySQL, CSV, SQLite etc for later
> >
> > The reasoning behind this is that I have a small machine that connects
> > to a database and does a lot of calculations. To `cache' calculated
> > results, it uses a hash, which has outgrown the available memory space,
> > so I tied that with "DB_File" to disk. The system however didn't give
> > me enough space to store that, and the database server is huge and fast
> 
> Hi Merijn,
> 
> how does your module differ from Tie::DBI

A lot, but I think my UI would fit in if I can convince Todd :)

Tie::DBI maps to tables with fields

    tie %hash, "Tie::DBI", ...; $hash{$key_value}{field} = 1;

Tie::DBD maps to a temp table with only a key and a value field

    tie %hash, "Tie::DBD", ...; $hash{$key_value} = 1;

> (http://search.cpan.org/dist/Tie-DBI/)?
> Or is it just a try to have a new start, because of the inactivity at Tie::DBI?

My intention was/is to have a DBI replacement for DB_File, so the
*only* thing I have to change to use it is

    tie my %hash, "DB_File", "file.db", O_RDWR|O_CREAT, 0666;

with

    tie my %hash, "Tie::DBD", $dbh;

And the rest of my code will still work. With the current
implementation of Tie::DBI I would have to rewrite everything.

-- 
H.Merijn Brand  http://tux.nl      Perl Monger  http://amsterdam.pm.org/
using 5.00307 through 5.12 and porting perl5.13.x on HP-UX 10.20, 11.00,
11.11, 11.23, and 11.31, OpenSuSE 10.3, 11.0, and 11.1, AIX 5.2 and 5.3.
http://mirrors.develooper.com/hpux/           http://www.test-smoke.org/
http://qa.perl.org      http://www.goldmark.org/jeff/stupid-disclaimers/