Re: cache in memory
Re: cache in memory
- Subject: Re: cache in memory
- From: Chuck Hill <email@hidden>
- Date: Mon, 9 May 2005 09:06:47 -0700
Hi Arturo,
On May 8, 2005, at 5:44 PM, Arturo Pérez wrote:
Isn't it still true that EOF still needs to run the query to determine
which objects match?
No. That is true for normal EOs, but not ones marked Cache in Memory.
When you mark an entity as such, you are telling EOF: objects of this
entity will never change. There will be no new objects, no edits, and
objects will not be deleted. You can read them once from the data
store and never refer to it again." All fetches are qualified against
and returned from the snapshot layer only. I don't know what will
happen if you attempt to add/edit/delete one of these objects. It
will probably be OK for that one instance but unseen in the others.
I've only ever used it for things like lookup list objects where I know
the values are static.
That is, it still sends a query for primary keys to the database but
does not fetch the data but rather uses the in-memory cache to resolve
faults.
No, again that is how regular EOs work. It does not check the DB for
the primary keys of the Cache in Memory entities as it assumes that it
got them all when they were first read.
Chuck
On May 8, 2005, at 8:03 PM, Chuck Hill wrote:
Unless something has changed, the docs are correct. The first
reference to
any of the entity's objects will fetch all such objects into memory.
Any
subsquent fetches or fired faults will only go as far as the snapshot
layer. There should be no further DB access. I've verified this
recently
with 5.2.3.
Are you perhaps using a fetch spec with "refreshes refetched objects"
set
to true? I'm not sure what would happen in that case.
Chuck
At 07:13 PM 08/05/2005 -0400, Mike Schrag wrote:
So the docs for "cache in memory" on an entity make it sound like WO
won't need to hit the database again after the first full load. I'm
not seeing this behavior at all, though, which leads me to believe
I've misunderstood this flag. Even with cache in memory, I still see
queries to retrieve entities of the particular type that i flagged.
What is the actual definition of this field?
ms
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
chill@global-villag
e.net
This email sent to email@hidden
--
Practical WebObjects - a book for intermediate WebObjects developers
who want to increase their overall knowledge of WebObjects, or those
who are trying to solve specific application development problems.
http://www.global-village.net/products/practical_webobjects
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
email@hidden
This email sent to email@hidden
--
Practical WebObjects - a book for intermediate WebObjects developers
who want to increase their overall knowledge of WebObjects, or those
who are trying to solve specific application development problems.
http://www.global-village.net/products/practical_webobjects
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden