Thanks Russell, that's the info I was looking for! On Sat, Aug 11, 2012 at 11:23 AM, Russell Haering <russellhaer...@gmail.com> wrote: > Your update doesn't go directly to an sstable (which are immutable), > it is first merged to an in-memory table. Eventually the memtable is > flushed to a new sstable. > > See http://wiki.apache.org/cassandra/MemtableSSTable > > On Sat, Aug 11, 2012 at 11:03 AM, Aaron Turner <synfina...@gmail.com> wrote: >> So how does that work? An sstable is for a single CF, but it can and >> likely will have multiple rows. There is no read to write and as I >> understand it, writes are append operations. >> >> So if you have an sstable with say 26 different rows (A-Z) already in >> it with a bunch of columns and you add a new column to row J, how does >> Cassandra store the column/value pair on disk in a way to refer to row >> J without re-writing the row key or some representation of it? >> >> Thanks, >> Aaron >> >> On Fri, Aug 10, 2012 at 7:53 PM, Terje Marthinussen >> <tmarthinus...@gmail.com> wrote: >>> Rowkey is stored only once in any sstable file. >>> >>> That is, in the spesial case where you get sstable file per column/value, >>> you are correct, but normally, I guess most of us are storing more per key. >>> >>> Regards, >>> Terje >>> >>> On 11 Aug 2012, at 10:34, Aaron Turner <synfina...@gmail.com> wrote: >>> >>>> Curious, but does cassandra store the rowkey along with every >>>> column/value pair on disk (pre-compaction) like Hbase does? If so >>>> (which makes the most sense), I assume that's something that is >>>> optimized during compaction? >>>> >>>> >>>> -- >>>> Aaron Turner >>>> http://synfin.net/ Twitter: @synfinatic >>>> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & >>>> Windows >>>> Those who would give up essential Liberty, to purchase a little temporary >>>> Safety, deserve neither Liberty nor Safety. >>>> -- Benjamin Franklin >>>> "carpe diem quam minimum credula postero" >> >> >> >> -- >> Aaron Turner >> http://synfin.net/ Twitter: @synfinatic >> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & >> Windows >> Those who would give up essential Liberty, to purchase a little temporary >> Safety, deserve neither Liberty nor Safety. >> -- Benjamin Franklin >> "carpe diem quam minimum credula postero"
-- Aaron Turner http://synfin.net/ Twitter: @synfinatic http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & Windows Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. -- Benjamin Franklin "carpe diem quam minimum credula postero"
