Quote:
Originally posted by fossil
Pando,
"Not true if low number of rows is gonna be returned, the poster in no where states that this is going to return many rows and your statement simply doesnt fit in general"
"Here in no where you mentions about index, too general, does not apply to all cases, plus the poster says his indexes are being used by his predicates which means there are index and not as you said in your last post "Not having indexes on the columns in the where clause would have CBO do Full table scan". In his case his predicates are applied first for t1 then joined"
Can your statement fits in general ?.
My statement fits in general, here is how ?.
If you have small tables having small number of rows, then
you don't need indexes as tables are small, FTS will be faster
then index lookup.
If you very large tables multi million rows and joinig them then
also FTS will be fastest. Will do the join first, sorts them (if you
have order by) and starts returning rows while filtering.
Not having indexes indeed applies to almost all the cases
just on the cost of query returning few rows.
"As for original poster, you dont compare costs, that is used internally, not by you! And you should post the query plan for this kind of questions"
Cost can be misleading ?. Run the queries both ways and check
the timing.
AFAIK I have not made any statement like you did! I have not said this is good this is bad, I have not said this is gonna be faster. And your statements are contradicting, in one place it seems that you are backing up your statements using large tables but here you are talking about small tables.