brain-017

Where does Oracle process SQL statements ?

Programming,programming,programming…a way a of life.(kind of!) ┬áBut how many times do we actually stop to think about what we are doing ?
I decided to blog on this, because it is important to always keep in mind some basic concepts

Whenever we need to execute a SQL statement, Oracle allocates a private memory area called the context area.This area is where the SQL statements get parsed and processed. What this means is:  the information required for processing as well as the information retrieved after processing are stored there.

In the Oracle Architecture, the context area is also known as the shared pool.The shared pool is located in the variable portion of the System Global Area(SGA). To get a clear picture, look at the server architecture below :

I’m not going to detail how the SGA works, but if you’re curious i advise you to check out the oracle wiki or this blog .

Now that I explained where the SQL statements are processed , let me just make point out that whenever the user issues a SQL statement like : SELECT, INSERT, UPDATE, DELETE an implicit cursor is created. This cursor works like a pointer to the Shared Pool in the SGA.

As programmers, we can also create explicit cursors. These cursors work like a pointer to each row that is retrieved and allow us to work in each row at a time.

And that’s it for today !