What Is System Global Area (SGA)?

If you've ever wondered what the SGA is, don't worry. This one is a doozy and so we have a handy-dandy explanation for you! The System Global Area (SGA) is a critical relational database management system component. Oracle Corporation developed the SGA memory area by Oracle processes to hold shared database instance information essential to proper database functioning, including required incoming and internal control data. You see, the SGA is where all of your data goes. So if you're looking to find out what movies are playing at theaters near you tonight, whether there's any ice cream left in that freezer cabinet at work, or even how many followers you have on Social media, you can find all of those answers in the SGA. SGA provides a critical function in the RDMS but consumes significant system resources. As such, SGA optimization is a best practice for any system administrator to increase the overall performance and efficiency of the database. This guide will help you understand the purpose and function of the SGA and how it can be optimized for maximum performance. The sga_target parameter sets a target amount of memory in megabytes for the SGA. The parameter value should be large enough to read and write enough data to satisfy the requirements of all applications running on your system. The sgs_max_size parameter sets a maximum size in megabytes for the SGA. There is enough room for all processes running on your system and no more. The System Global Area (SGA) is a shared memory pool that Oracle uses to store information about its data structures, run-time environment, and other critical details. While you can manually allocate memory to individual SGA areas with initialization parameters, Oracle typically allocates memory automatically based on your system's needs.