解决enq: TX - index contention的常用方法
摘自：
Troubleshooting ‘enq: TX - index contention‘ Waits (Doc ID 873243.1)
o Rebuild the index as reverse key indexes or hash partition the indexes which are listed in the ‘Segments by Row Lock Waits‘ of the AWR reports
o Consider increasing the CACHE size of the sequences
o Rebuild or shrink associated index after huge amount of data purge
o Increase PCT_FREE for the index
解决enq: TX - index contention的常用方法
原文：http://blog.csdn.net/msdnchina/article/details/45922621