Skip to main content
Solved

Attribute Accumulation question


joepk
Influencer
Forum|alt.badge.img+20
  • Influencer

Hi all,

 

I am currently using a Dissolver with Attribute Accumulation > Accumulation Mode set to ‘Use Attributes From One Feature’.

How does FME decide which feature's attributes are used? I assumed it would be the first one to enter the transformer, but I couldn't find anything on this in the documentation.

 

Kind regards,
Joep

Best answer by hkingsbury

It looks like it depends on your version.

Comparing 2024.1 and 2021.2

 

2024.1 takes the first, where as 2021.2 takes the last

View original
Did this help you find an answer to your question?

5 replies

birgit
Influencer
Forum|alt.badge.img+16
  • Influencer
  • October 7, 2024

It looks like it actually uses the attributes from the last feature. Probably because it is the easiest in terms of memory.


joepk
Influencer
Forum|alt.badge.img+20
  • Author
  • Influencer
  • October 7, 2024
birgit wrote:

It looks like it actually uses the attributes from the last feature. Probably because it is the easiest in terms of memory.

Oh really? My workspace seems to use the first feature:

When changing the Sorter's Order to Descending, the _count attribute of the dissolved feature is 1.


hkingsbury
Celebrity
Forum|alt.badge.img+51
  • Celebrity
  • Best Answer
  • October 8, 2024

It looks like it depends on your version.

Comparing 2024.1 and 2021.2

 

2024.1 takes the first, where as 2021.2 takes the last


bwn
Evangelist
Forum|alt.badge.img+26
  • Evangelist
  • October 8, 2024

Similarly, I have had different FME versions behave differently for whether first/last feature for Transformers that have this kind of Attribute merging handling.

Earlier versions of FME Eg. 2018 I had to make sure it was the last feature, whereas when upgraded to FM2021 had to go around to all my Sorters that where in Descending Order to get the first feature to enter the Transformer Last, and reverse them all back the other way since in later versions it seemed that the First Feature entering the Transformer now got used for the Attribute values.


joepk
Influencer
Forum|alt.badge.img+20
  • Author
  • Influencer
  • October 8, 2024

How interesting. When birgit posted their reply I figured this had something to do with versions. Thanks everyone for the insights.

This seems like something Safe would want to put in the documentation of transformers with Attribute Accumulation parameters.


Cookie policy

We use cookies to enhance and personalize your experience. If you accept you agree to our full cookie policy. Learn more about our cookies.

 
Cookie settings