19.12 Linux - PGA MEMORY VERY LARGE DUE TO Q PROCESSES - BACKGROUND Streams EMON Regular Slave
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--Oracle Enterprise Linux 7.9 x64
--Oracle Database Enterprise Edition 19.12 (19-JULY-2021)
--Oracle Grid Infrastructure 19.12 (19-JULY-2021) for Standalone Server ( NOT RAC - GI HAS/ASM ONLY)
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After the 19.12 Patchset was applied the database instance started to show repeated ORA-4036 in the database alert log.
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"PGA_AGGREGATE_LIMIT has been exceeded but some processes using the most PGA
memory are not eligible to receive ORA-4036 interrupts. Further occurrences
of this condition will be written to the trace file of the DBRM process."
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It got to the point that it consumed all Linux memory and Linux start to swap.
This caused further ORA-4036 errors, and eventually was necessary to stop/start the database instance to free up the Linux memory,