Hi Paul,
Not sure what causes this in QGIS, but I can imagine this happens when
you need data for a manual selection. So you select 200 features on your
screen (by dragging a box) and then export them to a file? Or maybe QGIS
does this better but a plugin doesn't?
To add to this, I remember hitting a "maximum where clauses of 1000" in
Oracle a while ago, so this doesn't only affect performance but can
cause errors as well.
Regards,
Raymond
On 03-07-2020 14:11, Paul Wittle wrote:
Hi,
We noticed that one of our users was accidentally sending inefficient
(or possibly just massive) SQL statements to the Oracle database. I need
to do more work to try and replicate the behaviour but is anyone
familiar with how it can happen?
The query is in the form of select [statement] from table where ID = :a
OR ID = :b … OR ID = :xxab
We wondered why that would happen as normally you would just do a
spatial query or perhaps do that for a small number of rows but it
seemed to be doing it for a large number of rows.
Any tips to what might be the cause would help me to replicate the
issue; my working theory is trying to load too many features in the
attribute table but I’m not sure.
Thanks,
*Paul Wittle *
<https://www.dorsetcouncil.gov.uk/>
*Business Solutions Analyst (GIS)*
*ICT Operations *
*Dorset Council*
01305 228473
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