Increasing the PGA_AGGREGATE_TARGET parameter helps allocate more memory to the PGA.
PGA_AGGREGATE_TARGET
ALTER SYSTEM SET PGA_AGGREGATE_TARGET=2G SCOPE=BOTH;
Optimize SQL queries to reduce memory consumption. Use indexes, avoid Cartesian joins, and ensure proper use of joins and subqueries.
Adjust parameters such as WORKAREA_SIZE_POLICY and HASH_AREA_SIZE to manage memory usage effectively.
WORKAREA_SIZE_POLICY
HASH_AREA_SIZE
ALTER SYSTEM SET WORKAREA_SIZE_POLICY=AUTO SCOPE=BOTH;
Use tools like Oracle's V$PROCESS and V$SESSTAT to monitor memory usage and identify leaks.
V$PROCESS
V$SESSTAT
Enable AMM to let Oracle manage memory allocation dynamically.
ALTER SYSTEM SET MEMORY_TARGET=4G SCOPE=SPFILE;
If the error occurs due to insufficient PGA memory, increase the PGA_AGGREGATE_TARGET parameter:
ALTER SYSTEM SET PGA_AGGREGATE_TARGET=3G SCOPE=BOTH;
Suppose a query is consuming too much memory due to inefficient joins:
SELECT emp_id, emp_name FROM employees e JOIN departments d ON e.dept_id = d.dept_id WHERE d.dept_name = 'Sales';
Ensure the dept_id column is indexed to improve query performance and reduce memory usage.
dept_id
Use the following query to monitor PGA memory usage:
SELECT * FROM v$pgastat;