In this chapter we will look at optimizations related to both queries and DML operations.
The first two recipes will show some features that can speed up a query; the following four recipes are focused on different techniques useful to load data in the database, from external sources and from other tables inside the database.
We will also focus on the overhead introduced by indexes and triggers. We have seen in past recipes that using indexes can speed up our queries, resulting in faster execution. However, in the recipes of this chapter, we will see how over-indexing a table can lead to poor DML performance.
About loading data, we will see how to use the SQL Loader and Data Pump to load our data faster. Direct path inserting and creating table using select will help us to populate some tables using data already available in the database.