Behaviour of Decentralized AE in a less conectivity with IS

Question

Hi Friends,
I have no ideea how a decentralized AE work in case of long term of no conectivity( eg 1 day) in a integration process if it works.This is first.
I read help, notes, and i see that UME is dependent the ABAP Stack, but if Central server(IS_AE) is not running or the network not permit conectivity, MUST maintain start/stop localy for each Decentralized Adapter Engine after estabilishment of conectivity?
It is posible to maintain some parameters in J2EE Engine?
Thanks !
Best Regards
Bogdan

Answer 1

Yes, this is plain-table valued query:
Select au_id
From Authors
WHERE 1=0
But here
Select(Select au_id
FROM authors
WHERE 1=0)
you have a query on the form
   SELECT (scalar value)
The scalar value in this case is a subquery, a scalar subquery. A scalar subquery always returns a single row. If the set returned by the query is empty, the scalar return value is NULL. If the set includes more than one value, this is an error.
A different way to describe this is that the context is scalar, and this is why the subquery is scalar. All values in a SELECT list must be scalar with regards to the row returned. If you say
SELECT expr FROM tbl
And there are five rows in table, the query will return five rows. If expr is a nested query, this cannot lead to the query returning 3 or 33 rows. The query will return five rows, period.
There is also:
 Select au_id
 FROM  (Select au_id
        FROM authors
        WHERE 1=0) AS k
Here the context is tabular, and in this example you will get no rows back. With a diffrent WHERE clause you can get many rows back.
Erland Sommarskog, SQL Server MVP, [email protected]