[CASSANDRA-1488] Allow index sampling ratio to be configured in storage-conf

• Type: New Feature
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 0.7 beta 2
• Assignee: Jon Hermes
• Reporter: Jonathan Ellis

Authors

Jon Hermes

Reviewers

Jonathan Ellis

• Created: 09/Sep/10 20:26
• Updated: 16/Apr/19 09:33
• Resolved: 25/Sep/10 18:48

Description

Cassandra keeps a sample of row keys in memory to look up the right block of index entries, to look up row data with. This is kept in the SSTableReader.indexSummary field. (See Google's BigTable paper for a high-level description of how this index works; cassandra's is slightly different in the details but the idea is the same.)

We'd like to make IndexSummary.INDEX_INTERVAL configurable in storage-conf.xml, i.e., in the DatabaseDescriptor class. For 0.6, a global setting is fine.