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wdeng avatar image
wdeng asked ·

咨询个问题,在cassandra中,如果一个查询跨很多分区,是不是再怎么建索引都是的慢查询?

咨询个问题,在cassandra中,如果一个查询跨很多分区,是不是再怎么建索引都是的慢查询?

performancequerymulti partition
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wdeng answered ·

如果查询跨很多分区的话,索引起不了什么作用。你应该考虑使用异步方式,增加查询的并发量。这样的话,每一个分区会被Driver发送给最优的Coordinator节点处理。一般情况下,这些分区都会均匀在所有节点上分布(这是由Cassandra内部使用的Consistent Hashing算法的特性决定的),所以并发查询很多分区的话,你可以让所有的节点同时都扮演Coordinator的角色,这样效率更高。最后查询的结果在客户端合并。

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