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From Maik Musall <m...@selbstdenker.ag>
Subject Re: Lazy Attributes
Date Fri, 29 Nov 2019 10:29:51 GMT
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 <lon.varscsak@gmail.com>:
> 
> Yeah, it's a great idea.
> 
> On Thu, Nov 28, 2019 at 6:06 AM Maik Musall <maik@selbstdenker.ag> wrote:
> 
>> +1 sounds very useful to simplify the data model here and there
>> 
>>> Am 27.11.2019 um 13:06 schrieb Michael Gentry <blacknext@gmail.com>:
>>> 
>>> 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
>> 
>> 


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