[R] Merging big data.frame
Jeff Newmiller
jdnewmil at dcn.davis.CA.us
Wed Apr 17 08:43:03 CEST 2013
check out the sqldf package
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Sent from my phone. Please excuse my brevity.
avinash sahu <avinash.sahu at gmail.com> wrote:
>Hi all,
>
>I am trying to merge 2 big data.frame. The problem is merge is memory
>intensive so R is going out of memory error: cannot allocate vector of
>size
>360.1 Mb. To overcome this, I am exploring option of using data.table
>package. But its not helping in term of memory as merge in data.table
>is
>fast but not memory efficient. Similar error is coming.
>My inputs are
>inp1
> V1 V2
>1 a i1
>2 a i2
>3 a i3
>4 a i4
>5 b i5
>6 c i6
>
>inp2
> V1 V2
>1 a x
>2 b x
>3 a y
>4 c z
>
>I want merge(x=inp1, y=inp2, by.x="V1", by.y="V1")
>so the output
>
> V1 V2.x V2.y
>1 a i1 x
>2 a i1 y
>3 a i2 x
>4 a i2 y
>5 a i3 x
>6 a i3 y
>7 a i4 x
>8 a i4 y
>9 b i5 x
>10 c i6 z
>
>Is there a way to do this without using merge in data.table? or Is
>there
>any other solution to do this in more efficient and less memory ?
>
>thanks
>avi
>
> [[alternative HTML version deleted]]
>
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