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lib/DBD/Ovrimos.pm  view on Meta::CPAN

=head2 CONNECTIONS, SESSIONS AND TRANSACTIONS

One can have multiple connections to an Ovrimos database, up to
the limit specified by one's User License. Keep in mind that what the License
calls 'sessions' amount to what are called separate statements in DBI.
Underlying the DBI is a protocol using the ODBC-equivalent 'connections' and
'statements'. Sessions are kept live until commit/rollback, and that can
result in denial of service if you reach the License limit. The database 
handle will reuse an inactive statement handle, so finish() often.

Commit/rollback finish()'es implicitly all open cursors (that's the answer
one asks ODBC with SQL_CURSOR_COMMIT_BEHAVIOR and SQL_CURSOR_ROLLBACK_BEHAVIOR).

Cached statements are not available. In the near future it is planned to
cache SQL statements internally at the SQL Server, so preparing the same
SQL statement as some time before will return a new $sth but without the
cost associated with preparing from scratch.

=head2 DATA TYPES

All ODBC 2.0 data types are supported. The format of time/date values is

lib/DBD/Ovrimos.pm  view on Meta::CPAN

constructs. The modified source can also be found in the execution plan (see
above).

=back

=head2 LOW-LEVEL LIBRARY

The entire low-level library that implements the Ovrimos protocol
is included. The DBI driver is based on this library, but one could conceivably
use the library on its own. It is the only way, for the time being, to use
scrollable cursors and bookmarks, since the DBI does not support them (yet?).
See the package C<DBD::Ovrimos::lowlevel> in C<Ovrimos.pm>. No documentation is
provided in this version about the low-level library.

=head1 COMFORMANCE

There is a particularity concerning transactions: see
L</CONNECTIONS, SESSIONS AND TRANSACTIONS>.

Cached statements don't exist. Not even the function prepare_cached exists.
Do not use it! You won't find any relevant attribute either.