First, should you want to get a PhD? I was in a fortunate position of knowing since young age that I really wanted a PhD. Unfortunately it wasn’t for any very well-thought-through considerations: First, I really liked school and learning things and I wanted to learn as much as possible, and second, I really wanted to be like Gordon Freeman from the game Half-Life (who has a PhD from MIT in theoretical physics). I loved that game. But what if you’re more sensible in making your life’s decisions? Should you want to do a PhD? There’s a very nice Quora thread and in the summary of considerations that follows I’ll borrow/restate several from Justin/Ben/others there. I’ll assume that the second option you are considering is joining a medium-large company (which is likely most common). Ask yourself if you find the following properties appealing:
Every WHERE id = N query flows through codegen_select_full_scan(), which emits linear walks through every row via Rewind / Next / Ne to compare each rowid against the target. At 100 rows with 100 lookups, that is 10,000 row comparisons instead of roughly 700 B-tree steps. O(n²) instead of O(n log n). This is consistent with the ~20,000x result in this run.,这一点在福利姬中也有详细论述
Ранее министр иностранных дел страны Аббас Аракчи заявил, что Россия и Китай, помогают Ирану «политически и иначе». При этом глава МИД Исламской республики отказался озвучивать конкретные детали этой поддержки.,这一点在传奇私服新开网|热血传奇SF发布站|传奇私服网站中也有详细论述
文|公司研究室基金组,作者|张阳
2026-03-07 23:00:00