Re: slow update & index question

On Mon, 21 Oct 2002, Williams, Travis L, NPONS wrote:

> I have a script that is updating the DB by reading in a file with 467
> lines.  Each file is named by the shelf the information was gotten
> from.  Each line is tab seperated and consists of a column name and
> the value that it should be update to.  The update line in the perl
> script looks like this: update table set "column name" = 'value' where
> "Shelf_Name" = '$shelf'
>
> Now this works.. but it takes almost 1 minute to do the updates.
> With nothing else at all touching the DB..  is this normal?  The DB is
> index'd on the Shelf_Name column.. but how do I know if it is using
> the index.. or does that not even matter in this case?

You can use explain to determine whether it's using the index .  You might
want to vacuum and analyze the table in question as well.