On 20/11/12 11:50 AM, Markus Hoenicka wrote: > Mike Rylander<mrylan...@gmail.com> was heard to say: > >> I think I'd add three calls to the proposed API, though, for support >> of savepoints. They're part of the SQL standard, and supported by >> several SQL RDBMS' including Postgres (the db my project uses, and we >> use libdbi to connect to PG). The relevant PG documentation is >> available at http://www.postgresql.org/docs/9.1/static/sql-savepoint.html >> . I have wrappers for savepoints in my implementation, and they are >> very handy for complex DB interactions. >> > > Sounds like a no-brainer if it is as simple as you say. I don't keep > the SQL standard underneath my pillow, but is it safe to assume that > database engines are responsible to deal with any pending savepoints > if a transaction is committed (i.e. no extra work for libdbi)? > > This brings up another question. Applications should of course check > the "transaction_supported" and "savepoints_supported" driver > capabilities and act responsibly. But if a database engine does not > support savepoints, or transactions altogether, should libdbi just go > ahead when asked, or should it throw an error instead? I recall that > MySQL "supported" transactions in MyISAM tables using no-ops.
That is correct. The transactional engine is InnoDB, and it's the recommended one if you care about your data and its integrity. I would suggest that libdbi should not try to be clever here - it's basically infeasible to try and determine whether a sequence of statements is transactionally unsafe in some way. For one thing, storage engines can be mixed in one MySQL schema, and a sequence of statements can involve them in arbitrary combinations (which is very foolish, but still). A warning about MyISAM might be placed in the manual, however. I don't know anything about savepoints so can't comment on that part. --Toby > > regards, > Markus > ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
