Re: Best Way To Lookup From a Huge Table

FROM : Jens Alfke
DATE : Thu Mar 13 23:30:37 2008

On 13 Mar '08, at 2:11 PM, Karan Lyons wrote:

> The table itself is pretty simple: It's just two columns, one with 
> every zipcode in the US, and the other with the corresponding 
> weather code.


If the weather-codes are all as short as in your example, you could 
create a file that's just an on-disk flat array of weather-codes, 
indexed by zip code. In other words, if a weather-code is at most n 
bytes long, you just seek to zipcode*n in the file and read n bytes.

Assuming n==8 as in your example, it would be an 800kbyte file. (But I 
bet it will compress really well, so it'll increase your app's 
download size by much less than that.)

—Jens