You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@pig.apache.org by "Rohini Palaniswamy (JIRA)" <ji...@apache.org> on 2017/12/26 19:40:00 UTC
[jira] [Created] (PIG-5323) Implement LastInputStreamingOptimizer
in Tez
Rohini Palaniswamy created PIG-5323:
---------------------------------------
Summary: Implement LastInputStreamingOptimizer in Tez
Key: PIG-5323
URL: https://issues.apache.org/jira/browse/PIG-5323
Project: Pig
Issue Type: Improvement
Reporter: Rohini Palaniswamy
Assignee: Rohini Palaniswamy
Fix For: 0.18.0
http://pig.apache.org/docs/r0.17.0/perf.html#join-optimizations
{quote}
Optimization for regular joins ensures that the last table in the join is not brought into memory but streamed through instead. Optimization reduces the amount of memory used which means you can avoid spilling the data and also should be able to scale your query to larger data volumes.
To take advantage of this optimization, make sure that the table with the largest number of tuples per key is the last table in your query. In some of our tests we saw 10x performance improvement as the result of this optimization.
{quote}
We are not doing that in Tez and both the tables are materialized as InternalCachedBag.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)