Re: Long Running Update

On 23/06/11 16:05, Harry Mantheakis wrote:
> Hello
>
> I am attempting to run an update statement that copies two fields from
> one table to another:
>
>
> UPDATE
>   table_A
> SET
> (
>   field_1
> , field_2
> ) = (
> table_B.field_1
> , table_B.field_2
> )
> FROM
> table_B
> WHERE
> table_B.id = table_A.id
> ;
>

I frequently get updates involving a FROM clause wrong --- the resulting
table is correct but the running time is quadratic. You might want to
try a series of smaller examples to see if your query displays this
behaviour.

Mark Thornton