Re: Searching on Two Keys with OR?

[gerald_clark]

Joshua Spoerri wrote:

On Tue, 5 Aug 2003, gerald_clark wrote:
 

You are ORing on two different fields.  The index cannot be used to
check the value of z for an OR.
   

"ORing on two different fields" is what I have been asking about :).
Using a composite index was suggested, which strangely seems to work
only when there are no other columns in the table.
When there are no other columns in the table, it can scan the complete 
index file to satisfy the query.
If there are other fields, it would have to scan the entire index file, 
and then access the data file to pick up
the other fields.  It is faster to just scan the entire data file.

 

Why are you cross posting?
   

Initially because I didn't know which list was appropriate,
and later in response.
 



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