union all效率低下,大概union all数十张表,单表select仅需0.0003-0.002秒,但union all后需要0.6秒左右
想改善下效率
这种情况该用存储过程、视图、临时表哪种方法来解决?
回复讨论(解决方案)
很明显,你的数据组织的不合理
很明显,你的数据组织的不合理
难道从来不会有这种情况发生吗
组织合理就没有这种情况
你把同类数据垂直分配在数十个表中,就是不合理
组织合理就没有这种情况
你把同类数据垂直分配在数十个表中,就是不合理
这些表的结构不完全相同的。当时就是考虑到放在一张表会复杂。所以就分开了。不过后来发现要汇总时,问题就来了。
大家有没有好的办法。之前建立的那些表已经应用到一些功能上了。现在改也太大工程了。
你能说一下你的那些表的结构吗?
既然并不相同,那么叠加在一起的意义何在?
你能说一下你的那些表的结构吗?
既然并不相同,那么叠加在一起的意义何在?
我刚刚查了一下,7个表,分别是
1.销售凭证、红字销售凭证
2.采购凭证、红字采购凭证
3.收款凭证、付款凭证、转账凭证。
其中1组和2组结构是一样的,1组和2组只有一个字段不同。
3组中的收款凭证和付款凭证也是只有一字段不同,转账凭证的结构则是被收款凭证和付款凭证所包含。
补充一下,1组和2组各自内部的表结构是一样的。1组和2组之间只有一个字段不同。
1组和2组不同的字段是,
1组有‘销售单号、客户编码‘。
2组有 ’采购单号、供应商编码’。
1组和2组的表结构是这样,能合并成一个表吗?
数据量有多大啊?要达到分表的情况下了。分表的话,这种水平分也不合理吧。
你用 union 这不就对了!
这7个表是平行的,就算要连接也只能是 join
数据量有多大啊?要达到分表的情况下了。分表的话,这种水平分也不合理吧。
其实它们都是描述不同的东西。所以才分表的。
1.销售凭证、红字销售凭证
2.采购凭证、红字采购凭证
3.收款凭证、付款凭证、转账凭证。
你用 union 这不就对了!
这7个表是平行的,就算要连接也只能是 join
将1、2组表结构合并,3组表结构合并,这样合理么。
不必了吧?你不是说已经应用到一些功能上了吗?
不必了吧?你不是说已经应用到一些功能上了吗?
就是各自的一个增删查改的功能。我不知道这样设计,以后会不会有其它不好处理的地方出现。
愿意的话,你可以描述一下业务流程
刚刚那7个表是接下来要做的几个功能的数据来源。
比如,有一个日记账的功能,这个功能就是要从刚刚那7个表中的记录搜索有“银行存款和现金”这两个科目存在的明细记录。要把有这两个存的的明细都抽出来,然后汇总显示。
第二个,明细账功能,这个也是要从刚刚那7个表中搜索除了“银行存款和现金”以外的所有科目存在的明细记录,汇总显示。
第三个,科目汇总表,这个是在一定时间范围内,所有凭证按科目汇总。
第四个,总分类账,就是显示每个科目发生的所有明细记录。
可能描述的不是很好。请见谅。
union all 之后还做了order之类? 要不不该差这么大啊

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