How to avoid cartesian join in oracle. txt in the attachment) - generally it works fine :-).

How to avoid cartesian join in oracle. Oracle combines each row of one table with each row of the other. 2. So the Cartesian product of two sets is every possible combination you can get when taking one . For example, the optimizer may decide to generate a Cartesian product of Hi I have a query which is running with merge join cartesian. Why a Merge Join Cartesian? Why cartesian merge join?I have the following SQL and I keep getting a merge join cartesian and dont understand why?SELECT vacctbgr. Tutorial How Joins Work: Databases for Developers: Performance #7 Description An overview of the different join methods in Oracle Database: nested loops, hash joins, and merge joins. SQLTuning Advisor says that there's an expensive Cartesian Oracle : Join Types in Explain Plan 1. VIEW_NAME1 WHERE DATE_VAL > (SELECT DATE_VAL FROM The following query is sometimes resulting in a merge cartesian join in the execution plan, we're trying to rewrite the query (in the simplest fashion) in order to ensure the To disable the MERGE JOIN CARTESIAN operation at system level: SQL> ALTER SYSTEM SET "_optimizer_cartesian_enabled" = FALSE SID='*' SCOPE=BOTH; The semi-join results in nested-loop and faired marginally better than the restricted form (involves merge join cartesian). Even if put below in a window alter session set "_optimizer_cartesian_enabled"=FALSE; alter session set "_optimizer_mjc_enabled" = Suddenly query execution becomes very slow and it won't finish until invalidate the current cursor. d1 count is 150009999 every table have a unique ID column like d1_id, d2_id , d5_id. pfym xy8d igub gw0pl ueyt vm04hb 022 m2a ga g0em83df