Aman Sinha has posted comments on this change. ( http://gerrit.cloudera.org:8080/15457 )
Change subject: IMPALA-9517: [DOCS] Document broadcast_bytes_limit query option ...................................................................... Patch Set 2: (3 comments) http://gerrit.cloudera.org:8080/#/c/15457/2/docs/topics/impala_broadcast_bytes_limit.xml File docs/topics/impala_broadcast_bytes_limit.xml: http://gerrit.cloudera.org:8080/#/c/15457/2/docs/topics/impala_broadcast_bytes_limit.xml@42 PS2, Line 42: Sets the default limit for the size of the broadcast input. Setting such a limit Remove the word 'default' . Also, this is based on estimated sizes (based on statistics), not actual size of the broadcast input. So, how about something like: 'Sets the limit for the size of the broadcast input based on estimated size. The Impala planner may in some rare cases make a bad choice to broadcast a large table or intermediate result and encounter performance problems due to high memory pressure. Setting this limit will make the planner pick a partition based hash join instead of broadcast and avoid such performance problems.' http://gerrit.cloudera.org:8080/#/c/15457/2/docs/topics/impala_broadcast_bytes_limit.xml@51 PS2, Line 51: The default value is 32GB. A value of 0 causes the option to be ignored. Since the value is supposed to be specified in bytes (rather than in MB or GB), lets say something like 'The default value is 34359738368 (32 GB)' http://gerrit.cloudera.org:8080/#/c/15457/2/docs/topics/impala_broadcast_bytes_limit.xml@57 PS2, Line 57: set broadcast_bytes_limit=64; Similar to the prior comment, since this is specified in bytes, if you want to change it 64 GB you will have to give the expanded value. Let's use a smaller number as example: -- Change the default value to 16 GB set broadcast_bytes_limit=17179869184; -- To view, visit http://gerrit.cloudera.org:8080/15457 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I2f7eaacd5a885a7a5292d7694241d58e4f7b6282 Gerrit-Change-Number: 15457 Gerrit-PatchSet: 2 Gerrit-Owner: Kristine Hahn <[email protected]> Gerrit-Reviewer: Aman Sinha <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Comment-Date: Tue, 17 Mar 2020 21:26:46 +0000 Gerrit-HasComments: Yes
