I actually started with the third approach. But you bring up a good point about allowing the Dialect to access the DatabaseMetaData (and hence Connection) if it wanted to. So I would change that a bit. See the updated gist
On Wed, May 27, 2015 at 7:33 AM, Max Rydahl Andersen <mande...@redhat.com> wrote: > > > The old > > way was calling one or more of the 50,000 (give or take ;) true/false > > methods on Dialect at runtime. The new evolving approach is to build > > delegates/helpers at boot time that encapsulate all that. Most of that > > work so far is encapsulated by JdbcEnvironment. One piece of this > > JdbcEnvironment is this IdentifierHelper > > (JdbcEnvironment#getIdentifierHelper). > > > > Maybe it makes the most sense to psuedo-code some approaches: > > https://gist.github.com/sebersole/46b5b7968e748648f562 > > Of these I think the outline in "first approach" is the best > since it does give the Dialect a chance to actually "talk" to the > server to figure out a possible better lookup than the jdbcDriver does. > > But as you said the dialect must handle getting null passed in - just don't > see a better way to handle that. > > Could even keep the implicit contract of if you return null it will > do as described in "second approach" and have a decent fallback. > > /max > > > > > > > > > >> One concern about DatabaseMetaData that hit the tools a few times is > that > >> getting this can be extremely expensive for some drivers (I don't recall > >> which > >> exactly, but Oracle comes to mind ;) > >> > > > > We get this once per bootstrap. > > > /max > http://about.me/maxandersen > _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev