what version of cassandra are you using. I found a big performance hit when querying on the secondary index.
I came across this bug in versions prior to 1.1 https://issues.apache.org/jira/browse/CASSANDRA-3545 Hope that helps. 2012/4/25 Jason Tang <ares.t...@gmail.com> > And I found, if I only have the search condition "status", it only scan > 200 records. > > But if I combine another condition "partition" then it scan all records > because "partition" condition match all records. > > But combine with other condition such as "userName", even all "userName" > is same in the 1,000,000 records, it only scan 200 records. > > So it impacted by scan execution plan, if we have several search > conditions, how it works? Do we have the similar execution plan in > Cassandra? > > > 在 2012年4月25日 下午9:18，Jason Tang <ares.t...@gmail.com>写道： > > Hi >> >> We have the such CF, and use secondary index to search for simple data >> "status", and among 1,000,000 row records, we have 200 records with status >> we want. >> >> But when we start to search, the performance is very poor, and check >> with the command "./bin/nodetool -h localhost -p 8199 cfstats" , Cassandra >> read 1,000,000 records, and "Read Latency" is 0.2 ms, so totally it used >> 200 seconds. >> >> It use lots of CPU, and check the stack, all thread in Cassandra is >> read from socket. >> >> So I wonder, how to really use index to find the 200 records instead of >> scan all rows. (Supper Column?) >> >> *ColumnFamily: queue* >> * Key Validation Class: org.apache.cassandra.db.marshal.BytesType* >> * Default column value validator: >> org.apache.cassandra.db.marshal.BytesType* >> * Columns sorted by: org.apache.cassandra.db.marshal.BytesType* >> * Row cache size / save period in seconds / keys to save : 0.0/0/all >> * >> * Row Cache Provider: >> org.apache.cassandra.cache.ConcurrentLinkedHashCacheProvider* >> * Key cache size / save period in seconds: 0.0/0* >> * GC grace seconds: 0* >> * Compaction min/max thresholds: 4/32* >> * Read repair chance: 0.0* >> * Replicate on write: false* >> * Bloom Filter FP chance: default* >> * Built indexes: [queue.idxStatus]* >> * Column Metadata:* >> * Column Name: status (737461747573)* >> * Validation Class: org.apache.cassandra.db.marshal.AsciiType* >> * Index Name: idxStatus* >> * Index Type: KEYS* >> * >> * >> BRs >> //Jason >> > >
