speed of query - help

  Let's say I have a sql query that looks at 5 tables ...

Table A - 100 rows
Table B - 200 rows
Table C - 300 rows
Table D - 150 rows
Table E - 1000000 rows

  Assuming that it's possible, I always thought that joining the smaller tables together first would speed the query. Once Table A-D are joined, that entire result set is then joined with Table E. Only one large join is performed.

  However, after reading the Oracle 7 Server SQL Reference Manual, page 4-21 states that "the optimizer determines the order in which Oracle7 joins tables based on the join conditions, indexes on the tables, and, in the case of the cost-based optimization approach, statistics for the tables". So, I guess this means that the order that you list the tables in the where clause doesn't matter (btw I'm using the CBO).

  Does anybody have any insight regarding this topic?

--

-Keith

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Before you buy. Received on Fri Oct 22 1999 - 08:44:42 CDT