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equential read 1,138,905 5,212 5 22.4 User I/O
gc cr block 2-way 780,224 285 0 1.2 Cluster
log file sync 246,580 246 1 1.1 Commit
SQL*Net more data from client 296,657 236 1 1.0 Network
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Avg
%Time Total Wait wait Waits
Event Waits -outs Time (s) (ms) /txn
---------------------------- -------------- ----- ----------- ------- ---------
db file sequential read 1,138,905 N/A 5,212 5 3.8
gc cr block 2-way 780,224 N/A 285 0 2.6
log file sync 246,580 0 246 1 0.8
SQL*Net more data from clien 296,657 N/A 236 1 1.0
SQL*Net message from dblink 98,833 N/A 218 2 0.3
gc current block 2-way 593,133 N/A 218 0 2.0
gc cr grant 2-way 530,507 N/A 154 0 1.8
db file scattered read 54,446 N/A 151 3 0.2
kst: async disk IO 6,502 N/A 107 16 0.0
gc cr multi block request 601,927 N/A 105 0 2.0
SQL*Net more data to client 1,336,225 N/A 91 0 4.5
log file parallel write 306,331 N/A 83 0 1.0
gc current block busy 6,298 N/A 72 11 0.0
Backup: sbtwrite2 4,076 N/A 63 16 0.0
gc buffer busy 17,677 1 54 3 0.1
gc current grant busy 75,075 N/A 54 1 0.3
direct path read 49,246 N/A 38 1 0.2 自己理解：DRM(Dynamic Resource Management)理论上实现了对非master的节点提升为master节点，可以减少跨节点资源访问，但是却带来了更多的问题。假如一个rac集群中有两个节点，节点2在空闲时段cache了一张很大很大的表，到了业务繁忙时段，节点1需要访问该表，如果没有DRM，则会从存储中访问，但是如果有了DRM，就会在节点2中找到该cache资源，从节点2的cache中将该资源传到节点1，这样的话就会消耗大量的带宽，从而消耗了很多资源。
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