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Re: In-place updates in a MemTable?


After studying org.apache.cassandra.db.Memtable.put method it looks like the update is made in-place. The MemTable is just a mapping from a row key to a single btree of column values, and an update operation just updates the btree stored under the existing key.

On 02/03/2017 11:21 AM, Artur Siekielski wrote:
Hi,

if I issue an update to a row (non-PK keys), and the old row is still
stored in a MemTable, is the old row updated in-place in the MemTable,
or a new entry in the MemTable in created and the old row will be
removed only by the SSTable compaction process?

(Cassandra 2.1)