There is always an implied "and do computations on it before writing the
processed data out" when reading chunks of a file.
And you would almost certainly not be getting that error if you were not out of
memory. A good rule of thumb is that you need 4 times as much free memory to
process data than you need to read it in.
On November 8, 2024 6:08:16 PM PST, Val <valkremk at gmail.com>
wrote:>Hi Jeff,
>
>Memory was not an issue. The system only used 75% of the memory
>allocated for the job.
>
> I am trying to understand what "r read large file in chunks" is
doing.
>
>On Fri, Nov 8, 2024 at 7:50?PM Jeff Newmiller <jdnewmil at
dcn.davis.ca.us> wrote:
>>
>> Then you don't have enough memory to process the whole thing at
once. Not unlike stuffing your mouth with cookies and not being able to chew for
lack of space to move the food around in your mouth.
>>
>> Now, can you answer my question?
>>
>> On November 8, 2024 5:38:37 PM PST, Val <valkremk at gmail.com>
wrote:
>> >The data was read. The problem is with processing.
>> >
>> >On Fri, Nov 8, 2024 at 7:30?PM Bert Gunter <bgunter.4567 at
gmail.com> wrote:
>> >>
>> >> Is the problem reading the file in or processing it after it
has been read in?
>> >>
>> >> Bert
>> >>
>> >> On Fri, Nov 8, 2024 at 5:13?PM Jeff Newmiller via R-help
<r-help at r-project.org> wrote:
>> >>>
>> >>> Can you tell us what is wrong with the "chunked"
package which comes up when you Google "r read large file in chunks"?
>> >>>
>> >>> On November 8, 2024 4:58:18 PM PST, Val <valkremk at
gmail.com> wrote:
>> >>> >Hi All,
>> >>> >
>> >>> >I am reading data file ( > 1B rows) and do some
date formatting like
>> >>> > dat=fread(mydatafile)
>> >>> > dat$date1 <- as.Date(ymd(dat$date1))
>> >>> >
>> >>> >However, I am getting an error message saying that
>> >>> > Error: cons memory exhausted (limit reached?)
>> >>> >
>> >>> >The script was working when the number rows were
around 650M.
>> >>> >
>> >>> >Is there another way to handle a big data set in R?
>> >>> >
>> >>> >
>> >>> >Thank you.
>> >>> >
>> >>> >______________________________________________
>> >>> >R-help at r-project.org mailing list -- To UNSUBSCRIBE
and more, see
>> >>> >https://stat.ethz.ch/mailman/listinfo/r-help
>> >>> >PLEASE do read the posting guide
https://www.R-project.org/posting-guide.html
>> >>> >and provide commented, minimal, self-contained,
reproducible code.
>> >>>
>> >>> --
>> >>> Sent from my phone. Please excuse my brevity.
>> >>>
>> >>> ______________________________________________
>> >>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and
more, see
>> >>> https://stat.ethz.ch/mailman/listinfo/r-help
>> >>> PLEASE do read the posting guide
https://www.R-project.org/posting-guide.html
>> >>> and provide commented, minimal, self-contained,
reproducible code.
>>
>> --
>> Sent from my phone. Please excuse my brevity.
--
Sent from my phone. Please excuse my brevity.