GoldenGate CACHEMGR CACHESIZE

Does anyone know what is the impact of having a low CACHESIZE in GoldenGate Extract?

I have had to set it extremly low, 512MB because the source database runs large transactions such as updating million of rows, when this sort of transaction happens the extract process starts to suck physical memory (according to the doc should be virtual memory but NOT) because it caches the transaction in the memory. I have made some basic measurements and when the transaction consumes 1GB redo it needs around 3GB physical memory, obviously this is not acceptable because we have transaction which generates 5GB, 6GB redo so my only bet was setting a low cachesize.

Thanks!

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