Feeding a consolidation into a single element (cross-cube)

[harrytm1]

Hi all,

I have some questions further to my earlier post under "Impact of feeders on RAM". Before I start, I apologise for posting the same entry in a separate thread here. The reason is because the earlier thread is no longer receiving attention.

I'm currently using version 9.5.2. I had previously used 9.4.1, 9.5 and 9.5.1. It seems that this current version utilises more RAM for feeders as compared to others as I have encountered huge feeders that I never encountered before in similar size cubes.

I have not gone to deploy the same data files in earlier versions just to prove it, but will do so once i have a chance.

FYI, I'm using the following config parameters which I'm not sure will cause RAM issue with the current version:
ReevaluateConditionalFeeders=T
AllowSeparateNandCRules=T
AllRuleCalcStargateOptimization=T
PersistentFeeders=T
UseStargateForRules=T
ViewConsolidationOptimization=T

Next question is, I need to bring the Profit After Tax (PAT) data from Profit Loss cube into Retained Earnings (RE) account in Balance Sheet cube. So the rule in BS is:
['RE', 'Value'] = DB('Profit Loss', !Entity, 'PAT', 'YTD ' | !Period, !Year, !Version, 'Value');

Note that the YTD value from PL is required to flow into BS for the month.

I wrote the following feeder in PL cube:
['PAT', 'YTD Jan', 'Value'] => DB('Balance Sheet', !Entity, 'RE', 'Jan', !Year, !Version, 'Value);
NOTE: This is repeated over 12 feeders to take care of each month.

Doing this will mean that ALL PL accounts under consolidation PAT will feed into a single cell under "RE" element in BS cube as long as they have values. In addition, the feeding of YTD means all underlyin Period elements in PL cube will feed into the single Period element in BS cube.

How should the feeder be written to reduce the overfeeding? I'm thinking of just feeding the month like for like without YTD i.e.
['PAT','Value'] => DB('Balance Sheet', !Entity, 'RE', !Period, !Year, !Version, 'Value);

Hoever, the main culprit will be PAT. But I cannot safetly assume one account within PAT to always have value and the just feed from that single account. This is just one of the many feeder issues whenever a parent is fed into a single element, or a parent is fed into another parent (which causes a permutation). Correct?

Many thanks in advance!

[lotsaram]

Harry - from your question it is clear that you don't quite understand what "overfeeding" is. Overfeeding is when you feed a cell (that is mark it for consolidation) when that cell either has no rule attached to it or that cell has a rule but evaluated to zero. The reason you want to avoid overfeeding is that it consumes memory, makes the cube dense which can slow down calculation, and can require excessive rule save and server startup times.

Feeding from a top node consolidation to an individual element is not overfeeding. This is just saying that if any leaf descendent of the consolidation contains a value then the target element will be fed.

Hope this is clear.

[harrytm1]

Thanks for highlighting that.

In the case where a consolidation has 5 children, and I'm feeding this consolidation node into an element. If all 5 children have values, will 5 feeder markers be inserted into the data point of the receiving element? Or just one? It's a question whether it's 5 bytes or just 1 byte.

You stated that "Overfeeding is when you feed a cell (that is mark it for consolidation) when that cell either has no rule attached to it or that cell has a rule but evaluated to zero.".

In such cases, how do I stop feeding it? Given the syntax of feeder statement, we can not be specific about the area to be fed. And I'm avoiding using conditional feeders.

Please advise.

[qml]

In the case where a consolidation has 5 children, and I'm feeding this consolidation node into an element. If all 5 children have values, will 5 feeder markers be inserted into the data point of the receiving element? Or just one? It's a question whether it's 5 bytes or just 1 byte.

There's physically only room for 1 feeder flag per cell (you can think of it as a shadow cube that has the same dimensions as the cube being fed, but can only take 0/1 values). So a feeder can take up at most 1 bit, regardless of the number of different places your feeder statement is feeding it from (or the number of different feeder statements applied).

In such cases, how do I stop feeding it? Given the syntax of feeder statement, we can not be specific about the area to be fed. And I'm avoiding using conditional feeders.

This is one of the most complex areas in TM1. Basically, preventing overfeeding is not always practical or possible, but there are different possible techniques for optimising feeder statements, ranging from creating dedicated technical objects (mapping cubes, dimensions etc) to using conditional feeders that you wish to avoid (why?).
The most obvious approach is to feed from a number that determines whether your target cell is 0 or not.

[harrytm1]

thanks to all your replies. that helps!