Cassandra Order by 目前仅支持按照 PRIMARY KEY 中声明的顺序对列进行排序

Question

这是我用来创建表的查询:

CREATE TABLE test.comments (msguuid timeuuid, page text, userid text, username text, msg text, timestamp int, PRIMARY KEY (timestamp, msguuid));

然后我创建一个物化 View :

CREATE MATERIALIZED VIEW test.comments_by_page AS
    SELECT *
    FROM test.comments
    WHERE page IS NOT NULL AND msguuid IS NOT NULL
    PRIMARY KEY (page, timestamp, msguuid)
    WITH CLUSTERING ORDER BY (msguuid DESC);

我想获取按时间戳升序排序的最后 50 行。

这是我正在尝试的查询:

SELECT * FROM test.comments_by_page WHERE page = 'test' AND timestamp < 1496707057 ORDER BY timestamp ASC LIMIT 50;

然后出现此错误:InvalidRequest: code=2200 [Invalid query] message="Order by currently only support the ordering of columns following their declared order in the PRIMARY KEY"

我怎样才能做到这一点？

Answer 1

物化 View 规则与“标准”表规则基本相同。如果你想要一个特定的顺序，你必须在集群键中指定。

因此您必须将您的时间戳 放入聚类部分。