On Apr 8, 2014, at 5:31 PM, BareFeetWare <[email protected]>
wrote:
> for (NSDictionary* rowDict in query.resultArray) {
> NSLog(@"%@: (%@, %@)", rowDict[@"Name"], rowDict[@"Latitude"],
> rowDict[@"Longitude"]);
> }
>
> Or to just get row 3's value for Name:
>
> query.resultArray[3][@"Name"];
Watch out: I have found this degree of abstraction to become a major
performance bottleneck. It results in large numbers of object allocations and
message-sends during query evaluation. Late in development of the first
implementation of Safari RSS in OS X 10.4, I had to go through code like this
and try various nasty tricks to cache and reuse objects, to try to speed it up
enough, because it was too late to redesign the query APIs to be closer to the
metal.
The query API in FMDB itself is more efficient, and I think clearer, although
not perfect. In my current usage I make sure to only use the numeric-indexed
accessors (i.e. get column 2 rather than column “Latitude”) because they’re
much faster.
—Jens
_______________________________________________
Cocoa-dev mailing list ([email protected])
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to [email protected]
