Drupal Node Table and SQL Performance Question

This question os partially a Drupal question and partially a SQL question. I have decided to implement quite a few features on my site as nodes due to the ease and flexibility of all the node related modules. Drupal stores the basic information about a nodes in the Node table. Potentially my node table is going to be huge, perhaps with millions of rows. I understand from reading the documentation that large tables can slow down queries, particularly开发者_JAVA百科 in Joins. What i don't really understand is how to quantify that. I know that the specific query, the hardware and a number of other factors are involved, but I'm wondering all other variables being equal, is there some sort of equation of table size to query time? would a table with 100,000 rows take 10 times as long to execute a query than one with 10,000 rows?

The execution time of a query depends very much on the query and the structure of the database - particularly the indexes. It is entirely possible for a 10x size table to take 10x the time to search, and it's also entirely possible for a 10x size table to take exactly the same time to search.

MySQL's explain query feature is great for figuring out where your queries can be optimized to run faster.