Mysql 如何使用大量这样的连接优化SELECT查询？

我有一个视图，它被定义为一个SELECT波纹管。有没有办法优化这个？现在非常非常慢

SELECT 
    -- lots of columns 
FROM   (((((((((((`table1` `t1`
                  LEFT JOIN `table2` `t2`
                    ON(( `t2`.`userid` = `t1`.`userid` )))
                 LEFT JOIN `table3` `t3`
                   ON(( `t1`.`orderid` = `t3`.`orderid` )))
                LEFT JOIN `table4` `t4`
                  ON(( `t4`.`orderitemlicenseid` =
                     `t3`.`orderitemlicenseid` )))
               LEFT JOIN `table5` `t5`
                 ON(( `t1`.`orderid` = `t5`.`orderid` )))
              LEFT JOIN `table6` `t6`
                ON(( `t5`.`transactionid` = `t6`.`transactionid` )))
             LEFT JOIN `table7` `t7`
               ON(( `t7`.`transactionid` = `t5`.`transactionid` )))
            LEFT JOIN `table8` `t8`
              ON(( `t8`.`voucherid` = `t7`.`voucherid` )))
           LEFT JOIN `table9` `t9`
             ON(( `t8`.`voucherid` = `t9`.`voucherid` )))
          LEFT JOIN `table10` `t10`
            ON(( ( `t10`.`vouchergroupid` = `t9`.`vouchergroupid` )
                 AND ( `t2`.`territoryid` = `t10`.`territoryid` ) )))
         LEFT JOIN `table11` `t11`
           ON(( `t11`.`voucherid` = `t8`.`voucherid` )))
        LEFT JOIN `table12` `t12`
          ON(( `t12`.`orderid` = `t1`.`orderid` )))
GROUP  BY `t5`.`transactionid`

EXPLAIN将返回如下内容：

id  select_type table   type    possible_keys   key key_len ref rows    Extra
1   PRIMARY <derived2>  ALL NULL    NULL    NULL    NULL    11571   
2   DERIVED t1  ALL NULL    NULL    NULL    NULL    11737   "Using temporary; Using filesort"
2   DERIVED t2  eq_ref  PRIMARY PRIMARY 4   database.o.userID   1   
2   DERIVED t3  ref fk_tblOrderItemLicenses_tblOrders1  fk_tblOrderItemLicenses_tblOrders1  4   database.o.orderID  1   
2   DERIVED t4  ref fk_tblOrderItemLicenseRefunds_tblOrderItemLicenses1 fk_tblOrderItemLicenseRefunds_tblOrderItemLicenses1 4   database.oil.orderItemLicenseID 1   "Using index"
2   DERIVED t5  ref fk_tblTransactions_tblOrders1   fk_tblTransactions_tblOrders1   4   database.o.orderID  1   
2   DERIVED t6  ref fk_tblTransactionCardDetails_tblTransactions1   fk_tblTransactionCardDetails_tblTransactions1   4   database.t.transactionID    1   
2   DERIVED t7  ref fk_tblVoucherTransactions_tblTransactions1  fk_tblVoucherTransactions_tblTransactions1  4   database.t.transactionID    1   
2   DERIVED t8  eq_ref  PRIMARY PRIMARY 4   database.vt.voucherID   1   
2   DERIVED t9  ref fk_tblVoucherVoucherGroups_tblVouchers1 fk_tblVoucherVoucherGroups_tblVouchers1 4   database.v.voucherID    1   "Using index"
2   DERIVED t10 eq_ref  PRIMARY PRIMARY 4   database.vvg.voucherGroupID 1   
2   DERIVED t11 ref fk_tblUserVouchers_tblVouchers  fk_tblUserVouchers_tblVouchers  4   database.v.voucherID    1   "Using index"
2   DERIVED t12 ref fk_tblTaiwanInvoiceData_tblOrders1  fk_tblTaiwanInvoiceData_tblOrders1  4   database.o.orderID  1   

id选择类型表类型可能的键长度参考行额外
1主所有空值11571
2派生t1所有NULL 11737“使用临时；使用文件排序”
2派生的t2 eq_ref PRIMARY PRIMARY 4 database.o.userID 1
2个派生t3参考fk_tblOrderItemLicenses_tblOrders1 fk_tblOrderItemLicenses_tblOrders1 4 database.o.orderID 1
2衍生t4参考fk\u tblorderitem许可证退款\u tblorderitem许可证退款1 fk\u tblorderitem许可证退款\u tblorderitem许可证退款1 4 database.oil.orderItemLicenseID 1“使用索引”
2派生t5参考fk\u tblTransactions\u tblOrders1 fk\u tblTransactions\u tblOrders1 4 database.o.orderID 1
2导出的t6参考fk\u tblTransactionCardDetails\u tblTransactions1 fk\u tblTransactionCardDetails\u tblTransactions1 4 database.t.transactionID 1
2派生t7参考fk\u tblVoucherTransactions\u TbltTransactions 1 fk\u tblVoucherTransactions\u TbltTransactions 1 4 database.t.transactionID 1
2派生t8 eq_ref PRIMARY 4 database.vt.voucherID 1
2派生t9参考fk_TblvoucherGroups_tblVouchers1 fk_TblvoucherGroups_tblVouchers1 4 database.v.voucherID 1“使用索引”
2派生t10 eq_ref PRIMARY 4数据库.vvg.voucherGroupID 1
2派生t11参考fk_tblUserVouchers_tblUserVouchers fk_tblUserVouchers_tblUserVouchers 4 database.v.voucherID 1“使用索引”
2派生t12参考fk_tblTaiwanInvoiceData_tblOrders1 fk_tblTaiwanInvoiceData_tblOrders1 4 database.o.orderID 1

您可以创建一个“结果表”，将查询结果插入其中。您的项目从该结果选项卡读取其数据。然后创建一个作业（不确定mysql选项是什么），该作业每小时/天/周运行一次慢速查询，以使结果表保持最新

此外，通常的索引之类的东西，您可以创建一个“结果表”，将查询结果插入其中。您的项目从该结果选项卡读取其数据。然后创建一个作业（不确定mysql选项是什么），该作业每小时/天/周运行一次慢速查询，以使结果表保持最新

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此外，通常的索引输出是什么？尝试删除所有括号。（是的，所有的都有。）输出是什么？尝试删除所有括号。（是的，所有的都是。）这是我对一个类似的查询所做的，该查询包含很多连接和条件。我别无选择，只能每天运行它并将其存储在表中，因为查询需要运行几个小时！这就是我对一个类似的查询所做的，该查询包含很多连接和条件。我别无选择，只能每天运行它并将其存储在表中，因为查询需要运行几个小时！