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Editorial Team
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Asked: 2026-05-27T00:42:11+00:00

I have a view which is defined as a SELECT bellow. Is there any

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I have a view which is defined as a SELECT bellow. Is there any way to optimize this? Right now it is very very slow.

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 will return something like:

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
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1 Answer

  1. Editorial Team

    You could make a “result table” where you insert the result of your query into. You project reads its data from that result tabel. Then you create a job (not sure what the mysql options are) that runs the slow query every hour/day/week to keep the result table up to date.

    furthermore the usual stuff like indexs

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