In this chapter, we took a look at the Oracle memory structure. We started at the process and session level, examining the PGA and UGA, and their relationship. We saw how the mode in which we connect to Oracle will dictate how memory is organized. A dedicated server connection implies more memory used in the server process than under a shared server connection, but that use of a shared server connection implies there will be the need for a significantly larger SGA. Then, we discussed the main structures of the SGA itself. We discovered the differences between the Shared pool and the Large pool, and looked at why we might want a Large pool to “save” our Shared pool. We covered the Java pool and how it is used under various conditions, and we looked at the block buffer cache and how that can be subdivided into smaller, more focused pools.
Now we are ready to move on to the physical processes that make up the rest of an Oracle instance.
KeywordsMemory Management Memory Structure Memory Allocation Query Plan Shared Server
Unable to display preview. Download preview PDF.