SQL Memory Management in Oracle9i

Complex database queries require the use of memory-intensive operators like sort and hashjoin. Those operators need memory, also referred to as SQL memory, to process their input data. For example, a sort operator uses a work area to perform the in-memory sort of a set of rows. The amount of memory allocated by these operators greatly affects their performance. However, there is only a finite amount of memory available in the system, shared by all concurrent operators. The challenge for database systems is to design a fair and efficient strategy to manage this memory. Commercial database systems rely on database administrators (DBA) to supply an optimal setting for configuration parameters that are internally used to decide how much memory to allocate to a given database operator. However, database systems continue to be deployed in new areas, e.g, e-commerce, and the database applications are increasingly complex, e.g, to provide more functionality, and support more users. One import...

• Type: Journal
• Year: 2002
• Where: VLDB
• Authors: Benoît Dageville, Mohamed Zaït
• Keywords: Database, Database Systems, Operators, VLDB 2002