Unable to allocate memory

[zulfi123786]

I am trying to write to a hashfile using "Allow Statge Write Cache" option set. I am facing the following warnings.

djsStgFidelityBackFill_QC_52..hshTmpFidRed.lnkNewColmns: Read link private caching enabled, cache size (128MB)

djsStgFidelityBackFill_QC_52..hshStgFidelityTmp.lnkOtherArrFidelityWrite: add_to_heap() - Unable to allocate memory

Here is it trying to read all data from the source then put it into cache from there trying to write to hahsfile, where the source data is huge compared to cache memory hence throwing the above warning? and what is the heap concept here?
My job has run though with warnings, does it mean that there is a chance that the data might not have loaded accurately?

[ray.wurlod]

Probably not. But it wasn't able to use the read cache, because there was not enough space there for all the data. So it has read the hashed file from disk instead.

[zulfi123786]

Can some one throw some light on the function add_to_heap()

[ArndW]

it is an undocumented internal function which add data to the memory structure.

[chulett]

what is the heap concept here?

Heap concept.