Problems reading large amount of spatial data

Problems reading large amount of spatial data

Postby vmakkenz » Tue 23 Aug 2011 16:04

Not sure where to begin with this problem, it al started when we upgraded from 5.0.20 to 6 (we are now on 6.30.202)

We got a simple loop where we use a reader to get data with a sdo_geometry from oracle.

It started with cast exceptions that where the result of there beeing DBNull values in the SDO_ORDINATES OracleArray.

The next value in the array will give an IndexOutOfRange exception.

But the rest of the ordinates can be read normally

The data itself seems irrelevant in that the record that fails will be read fine when read alone.

I tried not accesing anything at all but then I got an error that said "Maximum capacity attained"

I have no clue whats hapening here.
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Postby StanislavK » Fri 26 Aug 2011 12:59

Could you please describe the problem in more details? For example, please specify the following:
- the script creating the database objects you are working with;
- the query you use to select the data (is it simple "select * from ..."?);
- the exact messages and stack traces of the exceptions you are getting.

If possible, please send us a small test project with which the issue can be reproduced.
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Postby vmakkenz » Fri 26 Aug 2011 19:26

I got some more info.

It turns out the problem is not new in 6 but also existed in 5.0.20
(we downgraded and still had the same problems)

Thats when we found out that we made some changes in our code in that in search screens where large amounts of data are retrieved we also retrieve the geometry.
It is in these search screens that the problem happens.

I tried to reproduce the problem with a simple unit test to remove as much of the noise as possible. Unfortunatly when the test becomes to simple the problem no longer occurs.

It seems that the problem occurs when the query does an outer join, if i remove the outer-join plusses the test works.

select p.GEOMETRIE
from akr.akrtabel05 a05
, spatial.lki_perceel p
where a05.muteinde = 0
and a05.iverv = 'N'
and a05.gemcod = p.gemeente(+)
and a05.pnum = (+)
and a05.sectie = p.sectie(+)
and a05.objindl = p.indexlt(+)
and a05.objindn = p.indexnr(+)
and p.datumafvoer is null

Since we didn't really need the geometry in the search screens we removed the colomn so the problem no longer occurs.

Still would like to see this problem solved because ists not that uncommon to query large amounts of spatial data with outer joins.
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Postby Shalex » Thu 01 Sep 2011 14:35

Please send us a small test project with the corresponding DDL/DML script to reproduce the issue in our environment. We cannot identify the reason of the problem at the moment.
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