[CASSANDRA-10309] Avoid always looking up column type

• Type: Improvement
• Status: Open
• Priority: Low
• Resolution: Unresolved
• Fix Version/s: 5.x
• Component/s: Legacy/Local Write-Read Paths
• Labels: perfomance
• Assignee: Carl Yeksigian
• Reporter: T Jake Luciani

Authors

Carl Yeksigian

• Created: 11/Sep/15 21:33
• Updated: 07/Mar/23 10:54

Description

Doing some read profiling I noticed we always seem to look up the type of a column from the schema metadata when we have the type already in the column class.

This one simple change to SerializationHeader improves read performance non-trivially.
https://github.com/tjake/cassandra/commit/69b94c389b3f36aa035ac4619fd22d1f62ea80b2

http://cstar.datastax.com/graph?stats=3fb1ced4-58c7-11e5-9faf-42010af0688f&metric=op_rate&operation=2_read&smoothing=1&show_aggregates=true&xmin=0&xmax=357.94&ymin=0&ymax=157416.6

I assume we are looking this up to deal with schema changes. But I'm sure there is a more performant way of doing this.

Issue Links

• is blocked by: CASSANDRA-11820 Altering a column's type causes EOF
• is related to: CASSANDRA-12443 Remove alter type support
• is related to: CASSANDRA-11697 Improve Compaction Throughput