Subject RE: [firebird-support] Query help - Email found in subject
Author Leyne, Sean

> Trying to figure out a way to do a search/query with decent performance.
> Table "Master" contains roughly 100 million records and table "Detail"
> contains roughly 200 million records.

> Unfortunately, this will cause a natural scan of the 100 million record
> "Master" table, and roughly 200 million subselects...
> Can anyone figure out a way to avoid a full table scan?

What is the "selectivity" of Detail rows to Master (What % of Master don't have Details)?

I am afraid that there won't be much that can be done to avoid the basic problem.