R – How to store Blobs in Drupal

Drupal has an internal mechanism for mapping from "/node/1234/" to "/blogs/look-at-what-my-cat-just-did". It's part of the core system, and used almost everywhere, on every request, without you even having to ask. It's fast enough you'll almost never notice it happening - there's plenty of other things in drupal that are -far- slower.

If you're concerned about how URLs are being displayed on the front-end - you should be using the url() function (and filters that do the same with node content) to handle look-ups going the other way.

Where Pathauto comes in is that, when you create or edit content, it will generate a number of entries in Drupal's url_alias table (based on whatever pathauto rules you've created). This is a one-time cost. Unless you're generating content at an astronomical rate - there is a negligible cost associated with doing this.

You're already paying the cost of looking up URL aliases by simply using Drupal. Without hacking core, you can't really avoid it. Storing "hundreds of thousands of path aliases" in the database isn't that big of a deal - if you break that down into the actual storage requirements, you're only looking at a handful of megabytes. Since the table's well indexed, look-ups will be virtually instantaneous. This is core functionality & happens regardless of Pathauto even being on your system.

Unless you have some very odd requirements for the types of URLs you want to map your nodes to, anything you do will simply be recreating a subset of Pathauto's existing functionality (and likely introducing a bunch of new bugs).

With the pathauto module you are able create aliases for your urls. You can setup a lot of rules and should be able to get quite far with it. I'm not certain how well it integrates with the prepopulation model. But the rest should be quite easy.