“Brent writes a fair post”:http://inessential.com/2010/02/26/on_switching_away_from_core_data on when Core Data is great and when it’s a performance bottleneck:
“I optimized as much as I could, spent tons of time in Shark, went all multi-threaded with Core Data, switched away from my own queuing system to NSOperationQueue, optimized the XML parsing, etc. But performance and memory use on my first-generation iPod Touch (my development test device) was still not nearly good enough with a big unread count (of around 10,000 items).”
If I had been writing that post I probably wouldn’t have praised Core Data as much as he did, although admittedly because I rarely use it, and not at all in any shipping applications. Its approach always seemed slightly wrong to me.
My main reason for sticking with SQL directly is that I know by coding at this lower level — with my own lightweight model objects on top of FMDB and utility methods for working with the Clipstart database — that if something is slow it’s my fault. I can fix things that are my fault. I can’t fix fundamental design problems in Apple’s code.