Question Index Reads Vs Table Reads

[Cringer]

Just a quick question to make sure my understanding is correct.
When I look at reads for a query, in most cases table and index reads are pretty much in line. But what does it mean if I have more index reads to table reads?

 

[TheMadDBA]

More index reads than record reads usually means one of a few things....

1) You did a lookup where there were no records that satisfied the index (find first country where country-code = "123")

2) You are using a word index

3) You used multiple indexes to resolve the query and Progress did some magic on the backend to merge the results without reading the actual records (merging ROWIDs)

There might be a few more that I can't think of off the top of my head, but those are the usual suspects. If the index selection is "off" you will see more record and index reads than required to retrieve the data set.

 

[Cringer]

Thanks - my understanding is not wrong. Phew.