search for: mmeachflush

Displaying 3 results from an estimated 3 matches for "mmeachflush".

2010 Jan 22
0
New version of package ff
...ecks. In case you experience unexpected performance problems with ff, here is a couple of recommendations based on FAQs: 1) Compare the size of data to be written at the same time to available RAM for your filesystem cache. If the data exceeds available RAM, then consider using caching="mmeachflush" instead of caching="mmnoflush", this will make write operations predictably slower but prevent write storms stalling some systems (observed under NTFS win32+64). You can set ff's caching option either with options(ffcaching="mmeachflush") before creating ff obje...
2010 Jan 22
0
New version of package ff
...ecks. In case you experience unexpected performance problems with ff, here is a couple of recommendations based on FAQs: 1) Compare the size of data to be written at the same time to available RAM for your filesystem cache. If the data exceeds available RAM, then consider using caching="mmeachflush" instead of caching="mmnoflush", this will make write operations predictably slower but prevent write storms stalling some systems (observed under NTFS win32+64). You can set ff's caching option either with options(ffcaching="mmeachflush") before creating ff obje...
2012 May 02
6
Quickest way to make a large "empty" file on disk?
R-helpers: What would be the absolute fastest way to make a large "empty" file (e.g. filled with all zeroes) on disk, given a byte size and a given number number of empty values. I know I can use writeBin, but the "object" in this case may be far too large to store in main memory. I'm asking because I'm going to use this file in conjunction with mmap to do parallel