Compaction in cassandra is merging data from multiple SS tables , does it perform splitting data from one ss table into multiple ones ?
Bringing together the Apache Cassandra experts from the community and DataStax.
Want to learn? Have a question? Want to share your expertise? You are in the right place!
Not sure where to begin? Getting Started
Hi @ashok.dcosta_187920: Compaction is the process of freeing up space by merging large accumulated data‐ files. So it is meant to merge smaller SST tables into a bigger one and not the other way around.
A compaction operation in Cassandra is performed in order to merge SSTables. SSTables are immutable, which helps Cassandra achieve such high write speeds. However, periodic compaction of these SSTables is important in order to support fast read performance and clean out stale data values. During compaction, the data in SSTables are merged: the keys are merged, columns are combined, obsolete values are discarded, and a new index is created.
For more details see How compaction works in Cassandra. Thanks!!
7 People are following this question.