ERROR: MIN/MAX window function error

Hari_rao

We are trying to find the Max of a column for Rows before the current row. So the query we are trying is
MAX(End_Date_col) over (partition by "all necessary cols"
ORDER BY Start_date_Col ASC ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)

We have about 90 Million records which is pumped into this function. But this function errors out with :

[Code: 3937, SQL State: 53000] [Vertica]VJDBC ERROR: MIN/MAX window function could not operate in memory

when the data size is beyond 9 Million records.
When we do just the order by in the MAX, the query does not give error but when we include the Window/ Range, it gives error.
What could be the reason? Is there a setting to increase the memory needed to perform this operation? We have enough free disk space - 486GB for data and 935GB for the temp part of database in vertica and memory(RAM) of about 48GB free.
Any suggestions on this will be really helpful.