Subject Re: [firebird-support] Does SIMILAR TO use an index?
Author Ann Harrison
On Fri, May 10, 2013 at 12:18 PM, W O <sistemas2000profesional@...>wrote:

> Yes Ann, you are right, but I said: "an index for the table", not for a
> subset of a table for retrieval.

Sorry to say, you've hit one of my hot buttons. When you're reading a text
book, do you
go to the index, read the first entry from there, go back to the index,
find and read the
next entry, and so on through the text? Probably not.

An index is a pointer to specific information in a table, not a guide to
all entries.
For the latter, reading in natural order is easier and faster. The only
time when
bouncing between index and data is desirable is when you want only the first
bit of a list of rows that is sorted in the same order as the index.

Good luck,


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