The explain
Select distinct quoteid, itemname, model Numbers, ver the from tbquotedata

Using the index for group - by

 

Id select_type table partitions type possible_keys key key_len ref rows filtered Extra 
1 SIMPLE tbquotedata range LianHeIndex LianHeIndex 303 85748 100.00 Using index for group - by 

Tbquotedata table has 1.2 million records, the current query speed Duration/Fetch 0.047 SEC/11.234 SEC


How to improve the query speed optimization, thank you!