Doubt on Group by PIPE
< Just a Question >
I have a large table around 47 million rows on which I am doing a group by on set of columns.. due to nature of data and count(*) group by , I expect less reduce in rows...as final output....may be to half....
< explain says as Group by PIPE, as I have sorted the columns>
My doubt
As per documentation...
a) does group by pipe..never do spill to disk ?
b) Do the output computed only in memory ?
In this case , result dataset if large and may not fin to memory.
I have a large table around 47 million rows on which I am doing a group by on set of columns.. due to nature of data and count(*) group by , I expect less reduce in rows...as final output....may be to half....
< explain says as Group by PIPE, as I have sorted the columns>
My doubt
As per documentation...
a) does group by pipe..never do spill to disk ?
b) Do the output computed only in memory ?
In this case , result dataset if large and may not fin to memory.
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