摘要：
前言：关于oracle sql查询的优化规则，一般建议大表最好只查询一次。那么，怎么样就能做到前一次的大表查询结果能被下一个查询用到呢？我认为WITH很不错。with a as (select dummy from dual),b as (select dummy from dual)select a.dummy,b.dummy from a,b where a.dummy = b.dummy /********************************/Starting in Oracle9i release 2 we see an incorporation of the SQL-9 阅读全文