when we need to increase/decrease size of SGA. and what is target size for it. it is any scripts that show us alert of issue in SGA
An Oracle database's SGA comprises memory pools that the database uses to speed up data access. For example, the database buffer cache holds a subset of data which enables user processes to access data without having to read from disk. A logical read is a process of reading data from the buffer cache that is substantially quicker than obtaining data from storage.
In AWR Report, the DB file sequential read wait for metric shows that the database has asked to read a block from storage, and the wait time is recorded. According to the AWR statistics, DB file sequential read wait events accounted for slightly more than half of the overall database time. As a result, raising the SGA size may enhance performance by allowing more data to be held in the database buffer pool, resulting in shorter wait times.
Adjust the size of the System Global Area (SGA) according to the Automatic Workload Repository (AWR) report's suggestion. By allowing more local reads, adding extra RAM to the Oracle database can enhance speed.
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