Problem with queries with filters on aliases.

[vadim]

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We have dp type "eRemont2" with only one 1 dp without aliases. "Select alert" from 1 dp takes 1,7 seconds if we use alias filter and don't find alias.

Code: Select all

SELECT ALERT    '_alert_hdl.._ack_state', '_alert_hdl.._ack_time',   '_alert_hdl.._add_value_7',   '_alert_hdl.._add_value_8',   '_alert_hdl.._class',
   '_alert_hdl.._direction',   '_alert_hdl.._ackable',   '_alert_hdl.._value',   '_alert_hdl.._text',   '_alert_hdl.._system_time',   '_alert_hdl.._comment',
   '_alert_hdl.._value_status64'
FROM '@*1*#'  WHERE  _DPT = "eRemont2"

Then we set alias “sfasfasdfasf1231231#”, and run query again. Execute time is 0.147.

Any way these queries don't find DPE with alert_hdl. Why does it take such time? Why if we have found one DPE with alias, it takes 0,147 seconds, but if not - 1,7 seconds?

WinCC OA 3.14 patch 24

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[leoknipp]

I have tested with WinCC OA 3.16 and executing the same query (with a different DPT as filter) takes only a few or 0 milli seconds and an empty result is returned.
How many datapoints are defined for the DP type eRemont2?
Can you observe the same behaviour in another system?

Best Regards
Leopold Knipp
Senior Support Specialist

[vadim]

How many datapoints are defined for the DP type eRemont2?

As I wrote above, just 1 datapoint. And this DP type is not used in other DP types as nested.

Can you observe the same behaviour in another system?

Yes, we tested this query on different projects, but not with WinCC OA 3.16

[leoknipp]

I have tested it again using WinCC OA 3.14 and also with this version I cannot see a long timespan for the query if no result is returned.
If you need further assistance please get in contact with your common WinCC OA support.

Best Regards
Leopold Knipp
Senior Support Specialist