Question

我阅读了有关存储时间序列数据https://academy.datastax.com/resources/getting-started-time-series-data-modeling

的Datastax文章

根据文章，它应该创建用于存储一些时间序列的宽行。像这样（文章图片）：我创建了表：

CREATE TABLE test.times ( id text, time timestamp, temperature text, PRIMARY KEY (id, time));

并插入一些值：

cqlsh> insert into test.times (id, time , temperature ) VALUES ( '1', '2013-04-03 07:03:00', '72F');
cqlsh> insert into test.times (id, time , temperature ) VALUES ( '1', '2013-04-03 07:03:01', '73F');
cqlsh> insert into test.times (id, time , temperature ) VALUES ( '1', '2013-04-03 07:03:02', '74F');
cqlsh> insert into test.times (id, time , temperature ) VALUES ( '2', '2013-04-03 07:04:02', '74F');
cqlsh> insert into test.times (id, time , temperature ) VALUES ( '2', '2013-04-03 07:04:03', '72F');

我使用sstabledump工具转储了我的时间表。然后我得到了下一个转储：

[
  {
    "partition" : {
      "key" : [ "2" ],
      "position" : 0
    },
    "rows" : [
      {
        "type" : "row",
        "position" : 15,
        "clustering" : [ "2013-04-03 07:04+0200" ],
        "liveness_info" : { "tstamp" : 1463419324694096 },
        "cells" : [
          { "name" : "temperature", "value" : "74F" }
        ]
      },
      {
        "type" : "row",
        "position" : 36,
        "clustering" : [ "2013-04-03 07:04+0200" ],
        "liveness_info" : { "tstamp" : 1463419332655070 },
        "cells" : [
          { "name" : "temperature", "value" : "72F" }
        ]
      }
    ]
  },
  {
    "partition" : {
      "key" : [ "1" ],
      "position" : 58
    },
    "rows" : [
      {
        "type" : "row",
        "position" : 73,
        "clustering" : [ "2013-04-03 07:03+0200" ],
        "liveness_info" : { "tstamp" : 1463419298628467 },
        "cells" : [
          { "name" : "temperature", "value" : "72F" }
        ]
      },
      {
        "type" : "row",
        "position" : 91,
        "clustering" : [ "2013-04-03 07:03+0200" ],
        "liveness_info" : { "tstamp" : 1463419310835537 },
        "cells" : [
          { "name" : "temperature", "value" : "73F" }
        ]
      },
      {
        "type" : "row",
        "position" : 112,
        "clustering" : [ "2013-04-03 07:03+0200" ],
        "liveness_info" : { "tstamp" : 1463419317481809 },
        "cells" : [
          { "name" : "temperature", "value" : "74F" }
        ]
      }
    ]
  }
]

我看到C *为每个新条目创建了新行。我做错了什么？如何使用CQL创建宽行？

Cassandra v.3.5

Answer 1

你做得对。宽行实际上意味着一个宽分区。您会看到包含多个逻辑id的分区（由cql rows标识）。这些分区是你想要的广泛。

C * 3.0存储引擎的链接

带有CQL 3的动态列

1 个答案: