Blog

ORA-04031: unable to allocate nn bytes of shared memory

Question: I am getting the error ORA-04031 Cannot allocate shared memory. I've tried increasing my init.ora shared_pool_size, but to no avail. What are some causes for the ORA-04031 error, and how do I fix it?

Answer: The ORA-04031 error has many root causes. Also, see MOSC notes 146599.1 and 396940.1 for more details for resolving the ORA-04031 error:

1.Heavy fragmentation of the shared pool - This can be fixed by increasing the shared_pool_size or doing a "alter system flush shared pool" or bouncing the instance.

2.Too many pinned packages - If you have pinned lots of packages with dbms_shared_pool.keep, they have not leave enough room for new work.

Ultimately the solution to a ORA-04031 error is adding RAM to shared_pool_size and/or shared_pool_reserved_size. In 11g and beyond , if using AMM, increase memory_max_size to resolve the ORA-04031 error.

The Oracle documentation has these notes on the ORA-04031 error:

ORA-04031: unable to allocate nn bytes of shared memory

Cause: More shared memory is needed than was allocated in the shared pool

Action: If the shared pool is out of memory, either use the dbms_shared_pool package to pin large packages, reduce your use of shared memory, or increase the amount of available shared memory by increasing the value of the INIT.ORA parameters "shared_pool_reserved_size" and "shared_pool_size". If the large pool is out of memory, increase the INIT.ORA parameter "large_pool_size".

The ORA-04031 error also happens when you are using automatic memory management (sga_max_size), and the memory specific is too small.

Follow me

Contact us for Training/ Job Support

Caution: Your use of any information or materials on this website is entirely at your own risk. It is provided for educational purposes only. It has been tested internally, however, we do not guarantee that it will work for you. Ensure that you run it in your test environment before using.