Question

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In TDWM we have a Priority Scheduler where we can map WD to AG, add new RP, AG etc. The key here is the 'Priority' that maps WD to AG. This 'Priority' can be set in the WD as 'Enforcement Priority' and can be mapped to AG in the Priority Scheduler screen in the TDWM. Uptill here the relation between TDWM's workloads and priority is clear, and this association can be confirmed by observing the SlgPriority field in the TDWM.WlcDefs table.

However the 'Priority Scheduler Administrator' shows a different picture of priority and the association between RP, AG, Perf Group, Perf Period looks to be contained in this administrator itself.

There seems to be no relation between the priority of these two (TDWM and PSA). Is this designed this way? If so, then what is the purpose of PSA? If not, then how can the priority in TDWM's Priority Scheduler be linked to PSA?

Thanks,

flag	asked Nov 16 at 12:28 Monis Iqbal 100●1●7

Kiki Sanchez · Accepted Answer · 2009-11-17 00:53:36Z UTC

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My understanding is that you use either one or the other. Once you start using TDWM you lose the old priority scheduler. So, no relation.

answered Nov 17 at 0:53

Kiki Sanchez
36●1

	ok, so if there's no relation then do u know how does PSA's priority operate on the system? because there is no criteria to allocate different queries to different AG/PG etc.? – Monis Iqbal Nov 17 at 8:47
	Also, in Teradata document 'Performance Management' (TD12) it's mentioned: "Note: If Teradata DWM category 3 is active, no Priority Scheduler modifications are allowed through the Priority Scheduler Administrator or schmon." which I think hints that they are related. – Monis Iqbal Nov 17 at 10:48
	I'd be more inclined to think that is TDWM category three is active that the PS settings in PSA or schmon are not longer being considered by Teradata for managing the workload. Thus the reason the manual is worded as such. – Rob Paller Nov 17 at 13:44
	@Rob I think I am inclining towards your thoughts as well now. One related question though (dunno if it's good to post it here or should it be a separate one). DBC.ResUsageSpma also has Priority related metrics (PSNumRequests, PSQWaitTime, PSServiceTime) but it doesn't mention what data these metrics represent: PSA's PS or TDWM's PS? My observation here is that whether I activate TDWM's category 3 or not, data is logged into these metrics so maybe it's logging data for both. Would you agree? – Monis Iqbal Nov 17 at 15:24
	One more note in favor of this conclusion (from the document TDWM User Guide): "When you activate WDs, Teradata DWM creates its own PSF configuration based on the PSF configuration already in place, and then modifies the configuration to incorporate the requirements you define for the workloads and Priority Scheduler configuration. Teradata DWM saves the original PSF configuration and restores it when you deactivate WD rules." – Monis Iqbal Nov 18 at 7:15

Relation between Priority Scheduler in Priority Scheduler Administrator and the Priority Scheduler in TDWM

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