thanks!

Oracle merge inserts or updates the rows into the table2 (i.e. merge table) based on the equijoin condition (i.e. (B.f1 = A.f1))

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I have 2 tables (more than 10 million rows each).

table1 has 3 columns

a - datatype - varchar, b - varchar, c - float

there is no primary key or index

there is data in column a,b & all the rows of column c have null value

table2 has same 3 columns

a - varchar, b - varchar, c - varchar

there is no primary key or index

there is data in column a,b,c...

I have a simple procedure to put the c value of table2 into c value of table1.

The procedure looks like this

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create procedure my_procedure as

begin

 declare @a nvarchar(255),@b nvarchar(255)

 declare @C nvarchar(255)

 declare c1 cursor dynamic

 for select a,b,c from table1

 open c1

 fetch next from c1 into @a,@b,@c

 while(@@fetch_status = 0)

 begin

  update table2

  set c = @C

  where a = @a and

  b = @b-2

  print @C

  print @a

  fetch next from c1 into @a,@b,@c

  if @@error <> 0

   print 'exception 1 ' + @@error 

 end

 close c1

 deallocate c1

end

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It takes arround 4 hrs to execute this procedure, is there a way to optimize this procedure code? (I dont have the rights to add keys to table or index..etc. only code changes) Its actually data transfer of column c from table1 to table2