Oracle Table Different connection modes are huge, this paper mainly summarizes what kind of table connection and corresponding adjustment method. Oracle Table mainly has five connection methods: nested loop connection (NESTEDLOOPS), sorted merge Connection (CLUSTER JOIN), Hash Join, INDEX JOIN, what is the connection method? I have to learn about their principle nested loop connection: Oracle The first line is read in the first line, then the data of the second line source is contrast. Put this result in the result set, then Oracle read the next line in the first line, until it is pushed All records in the first line source are processed. The first line source is called a drive table. Thus, we should know that this connection should be used in the following: The number of driver tables is small and the second line source The connected column includes an index, which is very efficient.
