1.pt-osc工具1.1.pt-osc简介pt-osc是pt-online-schema-change的简写，pt-online-schema-change是percona-toolkit工具包中用于在线变更DDL的工具1.2.pt-osc原理1.3.pt-toolkit安装#yuminstallperl-ExtUtils-CBuilderperl-ExtUtils-MakeMakercpan#yumload-transaction