jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

tkellen

-- First attempt:
EXPLAIN ANALYZE SELECT count(DISTINCT date_trunc('week',s)) FROM generate_series('1900-01-01'::date,CURRENT_DATE,interval '1 day') AS s;
                                                           QUERY PLAN                                                           
--------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=12.51..12.53 rows=1 width=8) (actual time=72.552..72.553 rows=1 loops=1)
   ->  Function Scan on generate_series s  (cost=0.01..10.01 rows=1000 width=8) (actual time=24.495..27.619 rows=40975 loops=1)
 Total runtime: 73.005 ms
(3 rows)

SELECT count(DISTINCT date_trunc('week',s)) FROM generate_series('1900-01-01'::date,CURRENT_DATE,interval '1 day') AS s;

svnlto

Setup new Mac with OSX Lion from scratch

These commands are good as of 2011-07-27.

Install Xcode 4

The download/install takes a while so start it first. When it finishes downloading you will still need to run it to complete installation.

iTerm2

Really the nicest choice for a terminal on OSX right now, especially with Lion style full screen support.