Re: Lazy Attributes

Well, we can't always control the DB schema we have to interface with...


On Fri, Nov 29, 2019 at 5:30 AM Maik Musall <[email protected]> wrote:

> I’ll add a little caveat though. If a query hits lots of rows and thus the
> optimizer decides to do a full table scan (or a partition scan), the
> database could still end up having to read the blobs from disk, only
> omitting them in the returned results. So there may still be
> performance-related reasons to keep such blobs in separate entities (or
> elsewhere), depending on the specific RDBMS and it’s configuration.
>
> > Am 29.11.2019 um 07:07 schrieb Lon Varscsak <[email protected]>:
> >
> > Yeah, it's a great idea.
> >
> > On Thu, Nov 28, 2019 at 6:06 AM Maik Musall <[email protected]>
> wrote:
> >
> >> +1 sounds very useful to simplify the data model here and there
> >>
> >>> Am 27.11.2019 um 13:06 schrieb Michael Gentry <[email protected]>:
> >>>
> >>> I just happened across an article on Hibernate which talks about lazy
> >>> attributes.  (A recent addition, I think.)  This essentially allows you
> >> to
> >>> flag an attribute/column as lazy and it'll be excluded from the
> original
> >>> SELECT query, but if you call the getter it will then fetch it in.
> This
> >> is
> >>> convenient for BLOB-type data that might happen to be in a main table
> >> with
> >>> other attributes (such as MIME types, file sizes, file names, etc).
> >>>
> >>> Thoughts on maybe adding this feature to Cayenne?  I can imagine
> there'd
> >> be
> >>> a "Lazy" column in Cayenne Modeler for the attributes to
> control/identify
> >>> them.
> >>>
> >>> Thanks,
> >>>
> >>> mrg
> >>
> >>
>
>