First confirm the problem, is the code operation of the query or connect oracle tool operation of the query, optimize the large amount of data from the first three two ways to start, first, build the index, this has to talk about: the main pin in your query conditions (i.e., where is in the where the back of the field to build an index, there are a few conditions of the field on the construction of a few, if there is a combination of conditions of the query, the construction of the joint index). The second point is that according to the data in the table, table partitioning, such as partitioning by time period, partitioning by region, partitioning by unit or department. Reduce the full table scan. Third, check the table space is large or small.