Blake Miner's Blog

One thing I never really liked about JavaScript was the way it treats null , undefined , and false .  It's just, well... weird. Another example of this that I discovered today... null is greater than or equal to zero, but it's not greater than 0, nor is it equal to zero.  WTF? null > 0 false null >= 0 true null == 0 false

Carla and I are planning on getting married sometime in October next year.  We need to pick a date, and that decision may  involve some science and mathematics.  :) For example, we want the weather to be nice.  To be more precise, we'd like the high temperature for the wedding day to be between 60 and 80 degrees Fahrenheit.  Obviously, we have both lived in Ohio our entire lives, and we have a pretty good idea of what the weather will be like.  We both hypothesised that October was a "hit or miss" sort of month; it could be cold, or it could be nice. But, for me, a simple hypothesis was not enough; I really wanted to know the probabilities of decent weather based on historical weather data.  Many websites on the Internet (i.e. almanac.com) charge you to review historical weather data, but Carla and I discovered a cool page on cleveland.com that provided exactly what we wanted.  I loaded the historical temperature data from 1903 to 2011 f...

http://xkcd.com/844/

Email sucks, and it's incredibly broken! I mean.... sending an email in Gmail is obviously quite trivial.  But working with SMTP and email servers... not so much. Most people take email for granted.  It was invented way before I was born... way before Windows 95, Windows 3.1, or even DOS!  What?!?! Yeah... so not surprisingly, email sucks.  Remember... DOS sucked and Windows 95 sucked (not at that time, of course).  In fact, email sucks so much, it makes me sad that we still use it.  It's almost embarrassing... almost as embarrassing as Internet Explorer. Don't believe me?  Just go to the Postfix mail server documentation page.  Their website is straight out of the late-80's.  I think there might be one  image on the entire website?  After all, we can't have those 4.8K modems downloading images... it will take too long, tie up your phone line, and waste too much bandwidth.  :) So, why am I complaining about email? ...

I'm pretty sure that if I've played 100 games and won exactly 1 of them, my winning percentage should be 1%. I might be wrong, though.  There is no rounding error when you do 1/100 * 100%.  Single-precision floating point number rounding error?  For some reason, I doubt it... Weird... and stupid... EDIT:  Wrote a C program to make sure that Microsoft's Minesweeper has a bug. $ cat main.c #include <stdio.h> int main() {         float x = 1.0 / 100 * 100;         printf("%f\n", x);         return 0; } $ gcc main.c; ./a.out 1.000000 ... Yep... sure does.

I recently asked  this question on StackOverflow  about how to join to a derived table using an index.  I found out that even if your derived table is generated with tables that use all of the proper indexes, and you try to join that derived table to a base table in your outer query, no indexes are used.  Ever... So, let's start with a contrived example (as we often do)... SELECT * FROM t1 JOIN (SELECT * FROM t2) AS derived_t2 ON t1.f1=derived_t2.f1; OK... so let me get this straight... even if t1.f1 and  t2.f1  are indexed, the join will still be a full table scan?  You betcha! Let me say that again...  whenever you write a subquery and try to join the derived table to your outer query tables, no indexes are ever used .  It's a full table scan. So, I think to myself... "Wow... so that's really stupid, actually... because I have tables that only have a few thousand rows in them, and the query performance is shit.  Like... ...

If you're like me, then you are probably building web applications using Node.JS and MySQL (and maybe Redis, too).  If so, you're probably going to need transactions, and you've probably already noticed that the current version of node-mysql doesn't support transactions yet.  :( But that's OK because I have a solution for you.  Check out node-mysql-queues on github .  This project provides pretty good support for MySQL transactions with a fairly simple API.  There are a couple of things to remember, though.  For one, Node.JS is very "callback-centric," so when executing a series of queries, you would normally chain the queries together with a series of callbacks.  node-mysql sort of changes this model, by allowing you to place queries on a queue to be executed in order.  If you only care about doing something when all of your queries are done, you can simply put your callback in the final query.  node-mysql-queues allows you to do the same...