Duplicated offset numbering when there are multiple storages in a single node (for example, just as in our execution test setup)

[GoogleCodeExporter]

What steps will reproduce the problem?
1. In execution test setup, run the following DDLs
/*schema*/
drop dataverse STBench if exists;
create dataverse STBench;
use dataverse STBench;
/* longitude: x, latitude: y */

create type SimpleGeoPlaceType as closed {
   coordinates: point,      /* geometry -> coordinates (first -> should be x, second -> should be y) */
    id: int64,             
    name: string,           /* properties -> name */
    tags: string,           /* properties -> tags (arrary of string) */
    categories: string,     /* properties -> classifiers -> category, type, subcategory (will be concatenated as a string) */
    phone: string           /* properties -> phone */
}
create dataset SimpleGeoPlace (SimpleGeoPlaceType) primary key id;

/* load  - adm file is attached*/
use dataverse STBench;
load dataset SimpleGeoPlace 
using "edu.uci.ics.asterix.external.dataset.adapter.NCFileSystemAdapter"
(("path"="nc1://data/SimpleGeoPlace_100.adm"),("format"="adm"));

2. run the following query

for $y  at $i in 
for $x in dataset SimpleGeoPlace
return $x
order by $i
return $i

What is the expected output? What do you see instead?
We should not see any duplicated i value which is offset number. 
But, when we have multiple storages as is in our execution test setup, then we 
currently see duplicated offsets as follows:

1
1
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
8
8
9
9
9
9
10
10
10
10
11
11
11
11
12
12
12
12
13
13
13
13
14
14
14
14
15
15
15
15
16
16
16
16
17
17
17
17
18
18
18
18
19
19
19
19
20
20
20
20
21
21
21
21
22
22
22
22
23
23
24
24
25
25
26
26
27
27
28
29

Original issue reported on code.google.com by kiss...@gmail.com on 11 Jul 2015 at 12:32

Attachments:

• SimpleGeoPlace_100.adm