Re: CoreData, reset a persistent store
Re: CoreData, reset a persistent store
- Subject: Re: CoreData, reset a persistent store
- From: Pierre Chatelier <email@hidden>
- Date: Thu, 16 Nov 2006 01:22:34 +0100
If you look at the code, I negated the call (![object isFault])
which means they are fully realized hence your memory consumption.
Yes, we agree on that
These objects either are already in memory or are some how firing
on the retrieval
Since they were fetched, yes, they must be in memory; they can be
faults (and they are), but the data is cached and firing the fault
costs almost nothing.
Fetching takes minimal memory and time, it is the firing of the
fetch into a fully realized object that costs the time and memory.
Here we disagree !
My opinion comes from the following documentation : CoreData
Programming Guide > Faulting and Uniquing > Realizing a managed object
we can read :
1)If you execute a fetch using executeFetchRequest:error:, this
always results in a round trip to the persistent store to fetch the
data. The objects returned in the results array are fully realized,
and their data is stored in a cache (held by the persistent store
coordinator).
my comment : that's what I do : I fetch, and this results in faults-
but-realized objects
2)If you fire a fault, Core Data does not go back to the store if the
data is available in the cache. With a cache hit, converting a fault
into a realized managed object is very fast—it is basically the same
as normal instantiation of a managed object. If the data is not
available in the cache, Core Data automatically executes a fetch for
the fault object; this results in a round trip to the persistent
store to fetch the data, and again the data is cached in memory.
my comment : "converting a fault into a realized managed object is
very fast", is true in my case since data was fetched and is
availabel in the cache.
Regards,
Pierre _______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
| References: | |
| | >CoreData, reset a persistent store (From: Pierre Chatelier <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Elise van Looij <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Pierre Chatelier <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Elise van Looij <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Elise van Looij <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: "Marcus S. Zarra" <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: "I. Savant" <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Pierre Chatelier <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: "Marcus S. Zarra" <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Pierre Chatelier <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: "I. Savant" <email@hidden>) |
| | >Re: CoreData, reset a persistent store (From: Pierre Chatelier <email@hidden>) |