Hi,
it's better to have 1 OLAP connection for 1 BW entitlement system .
otherwise you end up have to create as many OLAP connection as you have Bex queries.
regards,
H
p.s. i believe your 2nd question is wrongly worded. It is entirely possible to have multiple dataprovider queries (i.e. OLAP connections) in a webi report.