DataStax Academy FAQ

DataStax Academy migrated to a new learning management system (LMS) in July 2020. We are also moving to a new Cassandra Certification process so there are changes to exam bookings, voucher system and issuing of certificates.

Check out the Academy FAQ pages for answers to your questions:


question

qiuzeliang_194033 avatar image
qiuzeliang_194033 asked ·

写记录时指定ttl, 时间到期后会产生大量墓碑,这种方式对Cassandra的读写性能是否有影响?

例如,每天往一张表写1000W条记录,记录的ttl设置为1个月, 1个月后每天产生1000w个墓碑, 此时对这张表的读写性能是否有影响?

tombstonesttl
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1 Answer

Erick Ramirez avatar image
Erick Ramirez answered ·

这取决于上面有TTL的数据。 如果将TTL应用于整个partition,则tombstones不是问题。

如果要在clustering columns上应用TTL,则如果要遍历过期的行以获取live数据,则可能会出现问题。

我们将需要查看表的schema和带有TTL的查询,以便我们确定是否会出现问题。

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