stored procedures and dynamic queries

[Ivan Sergio Borgonovo <mail@xxxxxxxxxxxxxxx>]

Any general rule about dynamically generated queries in stored
procedures vs. performances?

I was going to write stuff as simple as

create or replace function EditQty(int, int, int, varchar(10))
 returns boolean as
'
declare
	_uid alias for $1;
	_aid alias for $2;
	_qty alias for $3;
	_table alias $4;
	_modified timestamp;
begin
	_table := 'shop_commerce_basket' || _table
	_modified := now();
	update _table
	set qty=_qty,
	modified=_modified
	where uid=_uid and aid=_aid;
	if not found then
		insert into _table (uid, aid, qty)
		values(_uid,_aid,_qty);
	end if;
end;
' language plpgsql;

Is it going to perform worse than with a static table name?

Where can I find some clue about the effects of similar decisions?

thx

-- 
Ivan Sergio Borgonovo
http://www.webthatworks.it


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