@Bhuvan Rawal @Jasonstack Thanks a lot, it's very helpful!
------------------ 赵豫峰 环信即时通讯云/研发 ------------------ Original ------------------ From: "Bhuvan Rawal"<bhu1ra...@gmail.com>; Date: Mon, Mar 27, 2017 08:42 PM To: "user"<user@cassandra.apache.org>; Subject: Re: why dose it still have to seach in SSTable when getting data in memtable in the read flow？ Also Cassandra working unit is Cells so in a partition there may be possibility of some cells in a row being present in memtable and others may be located in memtable therefore the need of reconciling partition data. @Jason's point is valid too - User defined timestamp may put sstable cells ahead of memtable ones. Thanks, Bhuvan On Mon, Mar 27, 2017 at 5:29 PM, jason zhao yang <zhaoyangsingap...@gmail.com> wrote: Hi, Cassandra uses last-writetime-win strategy. In memory data doesn't mean it is the latest data due to custom write time, if data is also in Sstable, Cassandra has to read it and reconcile. Jasonstack On Mon, 27 Mar 2017 at 7:53 PM, 赵豫峰 <zha...@easemob.com> wrote: hello, I get the message that "If the memtable has the desired partition data, then the data is read and then merged with the data from the SSTables. The SSTable data is accessed as shown in the following steps." in "how is data read?" chapter in http://docs.datastax.com/en/archived/cassandra/2.2/cassandra/dml/dmlAboutReads.html. I do not understand that why have to read SSTable when it has got target data in memtable. If the data is in memtable, it means that data is lastest one, is there any other reason that it still has to seach in SSTable? Thanks！ ------------------ 赵豫峰 环信即时通讯云/研发
