In the previous chapter, we talked about the process of query execution and found out what went wrong by looking at plans, then fixing it. Sometimes, a query itself could be the reason for performance issues, so we talked about tuning as well; and sometimes, it is just that some settings need to be changed to make a query perform better. We also covered available caches and how to install them as extensions. In this chapter, we will cover extensions.
What is an extension?
How do we create/build/install them?
How do we use database links?
Importing/exporting images into databases