Memory Sizing

Legacy databases and earlier versions of Oracle use varying amounts of database server main memory, as they were optimized for the hardware platforms’ memory capacities of the time. It is important to ensure that a new single consolidated database or all of the databases consolidated to the single Oracle Exadata Database Machine have access to at least the same amount of “usable” memory as before. As some legacy systems could be oversized on memory, it is also important to review the database usage reports to see the actual “peak” memory that is used by each database. When migrating from another database where structures such as the Oracle PGA do not exist, memory should be carefully sized to ensure that the applications can take best advantage of the new Oracle environment.