query estimation shows cost 900%?# Database - 数据库
f*e
1 楼
I run SQL query estimated execution plan again one query.
The plan showed that the cost of "delete" and "insert" is 900%.
What does that mean?
PS: Which one of the following queries is better?
Query1:
if exist (select * from table1 where ...)
begin
update table1 set ...
end
else
begin
insert into table1 ...
end
Query2:
if exist (select * from table1 where ...)
begin
delete from table1 where ...
end
insert into table1 ...
Query3:
delete from table1 where ...
insert into table1 ...
The plan showed that the cost of "delete" and "insert" is 900%.
What does that mean?
PS: Which one of the following queries is better?
Query1:
if exist (select * from table1 where ...)
begin
update table1 set ...
end
else
begin
insert into table1 ...
end
Query2:
if exist (select * from table1 where ...)
begin
delete from table1 where ...
end
insert into table1 ...
Query3:
delete from table1 where ...
insert into table1 ...
