Streams aq enqueue blocked on low memory4/17/2023 When the streams pool finishes shrinking, the value should return "0", but if it keeps returning "1", you may encounter this problem. This value indicates that the streams pool is in the shrinking phase. The key information I got was this: If the size of the streamspool is being modified, then this can result in excessive waits for Streams AQ: enqueue blocked. And sometimes there may be Streams AQ: enqueue blocked on low memory errors in expdp log and alert log, but note that it may not be, but it is possible. If you encounter similar performance problems, please check whether the following query always returns "1". OUI-67301: The following patches have conflicts. ![]() In the Auto SGA environment (sga_target or memory_target is set), this problem may occur when the buffer cache load is high and the memory in the streams pool is being moved to the buffer cache. I get this warning applying Patch 21286665: EXPORT IS SLOW WAITING FOR 'STREAMS AQ: ENQUEUE BLOCKED ON LOW MEMORY' with OPatch 11.2.0.3.11 but the Patch finally didn't apply. Waiting events in the database will also prompt Streams AQ: enqueue blocked on low memoryĪnd sometimes there may be Streams AQ: enqueue blocked on low memory errors in expdp log and alert log, but note that it may not be, but it is possible. > 1 Streams AQ: enqueue blocked on low memory 2 In a RAC environment, it can improve the speed of Data Pump API-based operations and avoid some Parallel DML bugs at the same time.SQL> select inst_id,event,count(1) from gv$session where wait_class# 6 group by inst_id,event order by 1,3 Either leave this parameter unset or set this. Cause: streamspoolsize is autotuned with. When set explicitly to a value of 0, it can negatively impact the speed of Advanced Queue operations, which in turn can negatively affect Data Pump operations since Data Pump uses Advanced Queueing. Streams AQ: enqueue blocked on low memory during data pump export. ideally, the export backup was completed between one to two hours. Either leave this parameter unset or set this parameter to a value that is greater than 0. You can use parallel to speedup the datapump jobs. In this article, we are going to discuss the oracle wait event Streams AQ: enqueue blocked on low memory due to this wait event we are facing a performance issue in the export backup, today my export backup was in a hung state and it takes a very long time. When set explicitly to a value of 0, it can negatively impact the speed of Advanced Queue operations, which in turn can negatively affect Data Pump operations since Data Pump uses Advanced Queueing. You can use parallel to speed up the datapump jobs. I would recommend excluding the statistics during export because data pump jobs can hang, sometimes indefinitely when concurrent statistics generation for the same table is being performed by both the Data Pump engine and by any other users. To avoid STREAMS AQ: ENQUEUE BLOCKED ON LOW MEMORY error, you must set the STREAMSPOOLSIZE value returned by the result set of the following query. In a RAC environment, it can improve the speed of Data Pump API-based operations. SQL> ALTER SYSTEM SET STREAMS_POOL_SIZE=100M SCOPE=both EXPDP And IMPDP Slow Performance In 11gR2 and 12cR1 And Waits On Streams AQ: Enqueue Blocked On Low Memory (ID 1596645. In database version 11.2.0.4, Oracle has implemented a new algorithm for modifying components of the SGA memory, which has issue while changing the size of the stream pool size. After digging, Oracle MOS portal helped me in this case. Select 'ALTER SYSTEM SET STREAMS_POOL_SIZE='||(max(to_number(trim(c.ksppstvl))) 67108864)||' SCOPE=SPFILE ' from sys.x$ksppi a, sys.x$ksppcv b, sys.x$ksppsv c where a.indx = b.indx and a.indx = c.indx and lower(a.ksppinm) in ('_streams_pool_size','streams_pool_size') Almost 94 of time was spent on the Streams AQ: enqueue blocked on low memory wait event. ![]() To avoid “STREAMS AQ: ENQUEUE BLOCKED ON LOW MEMORY” error, you must set the STREAMS_POOL_SIZE value returned by the result set of the following query. Streams AQ: enqueue blocked on low memory processing issue Read of datafile ‘E:\ORADATA\ORCL\TEMP01.DBF’ (fno 201) header failed with ORA-01202 Leave a Reply Cancel reply Enter your comment here. Parameters Affecting Datapump Performance: Streams AQ: enqueue blocked on low memory 4928 59.91 8147.57 wait for unread message on broadcast channel 27 1.00 20.21 db file sequential read 886 0.02 0.77. ![]() To make expdp and impdp backup faster, you must read this article and set the below parameters based on your requirement and the database configuration. Almost 94 of time was spent on the Streams AQ: enqueue blocked on low memory wait event. There are some Data Pump Parameters that Significantly affect the export and import Performance.
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