is there any fast way to query average without including itself in mysql : for below table name: team_score 

"Team"	"score"	"date"
"A"	"1"	"2017-07-01"
"B"	"2"	"2017-07-02"
"A"	"3"	"2017-07-02"
"B"	"4"	"2017-07-01"
"C"	"5"	"2017-07-02"
"C"	"6"	"2017-07-01"

to get this table

"team"	"avg"	"avg_excluding_itself"
"A"	"2.00000000"	"4.25000000"
"B"	"3.00000000"	"3.75000000"
"C"	"5.50000000"	"2.50000000"

what will be the most efficient way?

below query will not work as it is too resource consuming. imaging the table is 100GB in size.

  

      select a.team, avg(a.score) as avg,avg(b.score) as avg_excluding_itself
    from team_score a join team_score b on a.team<>b.team
    group by a.team


