Cassandra 卡桑德拉：排序问题，；订购是错误的

我有一个关于卡桑德拉的问题。目前，通过column1排序，18位uuid上的“entities_by_time”是可以的，但uuid升序到19位排序时出现了一些问题。请帮帮我

cqlsh:minds> select * from entities_by_time where key='activity:user:990192934408163330' order by column1 desc limit 10;
 key                              | column1            | value
----------------------------------+--------------------+--------------------
 activity:user:990192934408163330 | 999979571363188746 | 999979571363188746
 activity:user:990192934408163330 | 999979567064027139 | 999979567064027139
 activity:user:990192934408163330 | 999979562764865555 | 999979562764865555
 activity:user:990192934408163330 | 999979558465703953 | 999979558465703953
 activity:user:990192934408163330 | 999979554170736649 | 999979554170736649
 activity:user:990192934408163330 | 999979549871575047 | 999979549871575047
 activity:user:990192934408163330 | 999979545576607752 | 999979545576607752
 activity:user:990192934408163330 | 999979541290029073 | 999979541290029073
 activity:user:990192934408163330 | 999979536990867461 | 999979536990867461
 activity:user:990192934408163330 | 999979532700094475 | 999979532700094475

cqlsh:minds> select * from entities_by_time where key='activity:user:990192934408163330' order by column1 asc limit 10;

 key                              | column1             | value
----------------------------------+---------------------+---------------------
 activity:user:990192934408163330 | 1000054880351555598 | 1000054880351555598
 activity:user:990192934408163330 | 1000054884671688706 | 1000054884671688706
 activity:user:990192934408163330 | 1000054888966656017 | 1000054888966656017
 activity:user:990192934408163330 | 1000054893257429005 | 1000054893257429005
 activity:user:990192934408163330 | 1000054897552396308 | 1000054897552396308
 activity:user:990192934408163330 | 1000054901843169290 | 1000054901843169290
 activity:user:990192934408163330 | 1000054906138136577 | 1000054906138136577
 activity:user:990192934408163330 | 1000054910433103883 | 1000054910433103883
 activity:user:990192934408163330 | 1000054914723876869 | 1000054914723876869
 activity:user:990192934408163330 | 1000054919010455568 | 1000054919010455568


CREATE TABLE minds.entities_by_time (
    key text,
    column1 text,
    value text,
    PRIMARY KEY (key, column1)
) WITH COMPACT STORAGE
    AND CLUSTERING ORDER BY (column1 ASC)
    AND bloom_filter_fp_chance = 0.01
    AND caching = {'keys': 'ALL', 'rows_per_partition': 'NONE'}
    AND comment = ''
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32', 'min_threshold': '4'}
    AND compression = {'enabled': 'false'}
    AND crc_check_chance = 1.0
    AND dclocal_read_repair_chance = 0.0
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.1
    AND speculative_retry = '99PERCENTILE';

---

通过调查发现，在卡桑德拉，1007227353832624141少于963426376394739730。为什么？

给克里斯打个好电话！表定义说明了一切！我重新创建了您的表，并在两个方向上运行查询排序：

flynn@cqlsh:stackoverflow> SELECT * FROM entities_by_time
     WHERE key='activity:user:990192934408163330'  ORDER BY column1 DESC;

 key                              | column1             | value
----------------------------------+---------------------+---------------------
 activity:user:990192934408163330 |  999979571363188746 |  999979571363188746
 activity:user:990192934408163330 |  999979567064027139 |  999979567064027139
 activity:user:990192934408163330 |  963426376394739730 |  963426376394739730
 activity:user:990192934408163330 | 1007227353832624141 | 1007227353832624141
 activity:user:990192934408163330 | 1000054884671688706 | 1000054884671688706
 activity:user:990192934408163330 | 1000054880351555598 | 1000054880351555598

(6 rows)

flynn@cqlsh:stackoverflow> SELECT * FROM entities_by_time
     WHERE key='activity:user:990192934408163330'  ORDER BY column1 ASC;

 key                              | column1             | value
----------------------------------+---------------------+---------------------
 activity:user:990192934408163330 | 1000054880351555598 | 1000054880351555598
 activity:user:990192934408163330 | 1000054884671688706 | 1000054884671688706
 activity:user:990192934408163330 | 1007227353832624141 | 1007227353832624141
 activity:user:990192934408163330 |  963426376394739730 |  963426376394739730
 activity:user:990192934408163330 |  999979567064027139 |  999979567064027139
 activity:user:990192934408163330 |  999979571363188746 |  999979571363188746

(6 rows)

所以对于你的问题

在卡桑德拉，1007227353832624141小于963426376394739730。为什么?

简单地说，因为9>1，这就是原因。

您的表定义聚集在

第1列

，这是一个文本/UTF8字符串，而不是一个数字。本质上，Cassandra是以它知道的唯一方式对字符串进行排序的——ASCII字母顺序，而不是字母数字顺序

---

将数字存储为数字，排序将以更可预测的方式进行。

“出错”是模糊的。通过详细阐述你所看到的错误，帮助不太熟悉的读者理解问题。此外，考虑使用预格式化工具来格式化错误消息。编辑您的问题并查看格式帮助。它将单空格的东西，这是特别有用的，当表一样的数据正在呈现。他们看起来都正确排序。你能详细说明一下你希望看到的不同点吗？排序顺序是正确的。检查所有数字，而不仅仅是列值中的最后4或5。通过排序“column1”找到。使用desc排序，“99979571363188746”是第一个，使用asc排序，“1000054803555598”是第一个。但“1000054803555598”比“99979571363188746”大。@JimWartnick通过排序“column1”找到。使用desc排序，“99979571363188746”是第一个，使用asc排序，“1000054803555598”是第一个。但“1000054803555598”大于“99979571363188746”。