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