> Will MMapping data files be detrimental for reads, in this case? No. > In general, when should we opt for MMap data files and what are the factors > that need special attention when enabling the same? mmapping is the default, so I would say use it until you have a reason not to.
mmapping will map the entire file, but pages of data are read into memory on demand and purged when space is needed. Cheers ----------------- Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 4/12/2012, at 11:59 PM, Ravikumar Govindarajan <ravikumar.govindara...@gmail.com> wrote: > Our current SSTable sizes are far greater than RAM. {150 Gigs of data, 32GB > RAM}. Currently we run with mlockall and mmap_index_only options and don't > experience swapping at all. > > We use wide rows and size-tiered-compaction, so a given key will definitely > be spread across multiple sstables. Will MMapping data files be detrimental > for reads, in this case? > > In general, when should we opt for MMap data files and what are the factors > that need special attention when enabling the same? > > -- > Ravi
