刘大,麻烦帮忙看下这个问题,我在测试impdp的性能,我同时起了10个线程做impdp操作。重复测了几遍之后,发现完成测试需要的时间不太稳定,时快时慢。每次测试我都会抓取相应时间段的ASH以及AWR报告。我注意到impdp变慢的时候,会有Streams AQ: enqueue blocked on low memory等待事件产生,请问这是什么原因造成的?有没有什么解决方法?
select * from v$version;
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
PL/SQL Release 10.2.0.5.0 - Production
"CORE 10.2.0.5.0 Production"
TNS for 64-bit Windows: Version 10.2.0.5.0 - Production
NLSRTL Version 10.2.0.5.0 - Production
OS
Windows server 2003 R2 Enterprise x64 Edition
RAM: 4GB
Show sga
Total System Global Area 1610612736
Fixed Size 2077936
Variable Size 754977552
Database Buffers 838860800
Redo Buffers 14696448
show parameter sga_
NAME TYPE VALUE
-------------------------------------------- ----------- ----------------------------------------------------------------------------
sga_max_size big integer 1536M
sga_target big integer 1536M
Streams Pool Advisory
Size for Est (MB) Size Factor Est Spill Count Est Spill Time (s) Est Unspill Count Est Unspill Time (s)
16 0.50 0 0 0 0
32 1.00 0 0 0 0