What is the cause and solution for ORA-04036 : PGA memory used by the instance exceeds PGA_AGGREGATE_LIMIT error?
The Program Global Area (PGA) is a memory region that contains data and control information for a single server process is used by sessions for session related activities such as sorting.
Cause: The PGA occupied by all the sessions exceeds the limits set by PGA_AGGREGATE_LIMIT initialization parameter.
Solution:
1. set the value of the PGA_AGGREGATE_LIMIT initialization parameter to zero. And this setting removes the hard limit on PGA usage for sessions.
SQL > alter system set pga_aggregate_limit=0 scope=both;
2. Increase the size of PGA_AGGREGATE_LIMIT initialization parameter
SQL > alter system set pga_aggregate_limit=2G scope=both;