SQLite Performance Benchmark — why is :memory: so slow…only 1.5X as fast as disk?

Why is :memory: in sqlite so slow? I’ve been trying to see if there are any performance improvements gained by using in-memory sqlite vs. disk based sqlite. Basically I’d like to trade startup time and memory to get extremely rapid queries which do not hit disk during the course of the application. However, the following … Read more

Python Multiprocessing.Pool lazy iteration

I’m wondering about the way that python’s Multiprocessing.Pool class works with map, imap, and map_async. My particular problem is that I want to map on an iterator that creates memory-heavy objects, and don’t want all these objects to be generated into memory at the same time. I wanted to see if the various map() functions would wring my iterator dry, or intelligently call the next() function only as child processes slowly advanced, so I hacked up some tests as such: