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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Update of "MemtableSSTable" by JonathanEllis
Date Fri, 09 Apr 2010 15:41:59 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Cassandra Wiki" for change notification.

The "MemtableSSTable" page has been changed by JonathanEllis.
http://wiki.apache.org/cassandra/MemtableSSTable?action=diff&rev1=3&rev2=4

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- Cassandra writes are first written to the !CommitLog, and then to a per-!ColumnFamily structure
called a Memtable.  A Memtable is basically a write-back cache of data rows that can be looked
up by key -- that is, unlike a write-through cache, writes are batched up in the Memtable
until it is full, before being written to disk as an SSTable.
+ Cassandra writes are first written to the [[Durability|CommitLog]], and then to a per-!ColumnFamily
structure called a Memtable.  A Memtable is basically a write-back cache of data rows that
can be looked up by key -- that is, unlike a write-through cache, writes are batched up in
the Memtable until it is full, before being written to disk as an SSTable.
  
  The process of turning a Memtable into a SSTable is called flushing.  You can manually trigger
flush via jmx (e.g. with bin/nodetool), which you may want to do before restarting nodes since
it will reduce !CommitLog replay time.  Memtables are sorted by key and then written out sequentially.
  

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