Ruby Performance Optimization

Take a Step Back

Looking at the profile again, we think we collected all the low-hanging fruit there. Row parsing is still slow, though. The first five rows in the flat profile are for functions that do that parsing. In short, we optimized individual functions, but the whole thing is still slow.

In such cases the next step in optimization is to look at the code at a higher abstraction level. In our case we’ll need to reexamine what the parsing code does. The first thing we note is that our code doesn’t take advantage of the fact that column order is predefined. The first column is always a number, the second a name, and the third a date. So instead of determining the column type in the if/else statement, we can just go ahead and parse it. ...