# general
- k
Kishore G
04/02/2019, 1:19 AMCan you send hard copy - s
Shireen Nagdive
04/02/2019, 1:20 AMhard copy? - k
Kishore G
04/02/2019, 1:20 AMSorry. Pdf - s
Shireen Nagdive
04/02/2019, 1:21 AMEASY Paper - s
Sunitha
04/02/2019, 1:51 AMShireen, if you are not seeing latency increase, your servers still have a lot of headroom - what was the server cpu? - s
Shireen Nagdive
04/02/2019, 2:15 AMyou mean server cpu load? - s
Sunitha
04/02/2019, 2:42 AMYes - cpu usage - s
Seunghyun
04/02/2019, 3:53 AMi also agree with @User. If your cpu utilization is low, 99th percentile latency can go down because you have more samples with normal latency. - s
Shireen Nagdive
04/02/2019, 6:31 PMYes, I have increased QPS. Let’s see what we get - c
Chinmay Soman
04/03/2019, 6:33 PMHey folks, wanted to understand the schema evolution bit. If we evolve the schema by adding a new column (with a default value) - will it automatically apply this default value to the old segments (created using old schema) ? - c
Chinmay Soman
04/03/2019, 6:33 PMWe see a behaviour where old segments are discarded - c
Chinmay Soman
04/03/2019, 6:33 PMIs this a bug / expected behaviour ? - k
Kishore G
04/03/2019, 6:33 PMthat seems to be a bug - c
Chinmay Soman
04/03/2019, 6:34 PMok , Ting filed this: https://github.com/apache/incubator-pinot/issues/4029 - k
Kishore G
04/03/2019, 6:34 PMif you restarted the serve or reloaded the segment, the default value - c
Chinmay Soman
04/03/2019, 6:34 PMI can take a look - but just wanted to know before I start to investigate - c
Chinmay Soman
04/03/2019, 6:34 PMyes restart was done - m
Mayank
04/03/2019, 6:37 PMAs a side note, this is handled byDefaultColumnHandler.updateDefaultColumns() - c
Chinmay Soman
04/03/2019, 6:38 PMack - k
Kishore G
04/03/2019, 6:38 PMok. looks like a bug. do you have the schema? - m
Mayank
04/03/2019, 6:38 PMIt is expected to be called when segment is loaded (that happens at restart)ImmutableSegmentLoader.load - c
Chinmay Soman
04/04/2019, 12:42 AMIt may be that our servers are somehow configured without "enable.default.columns" (the default seems to be false: https://github.com/apache/incubator-pinot/blob/master/pinot-server/src/main/java/org/apache/pinot/server/starter/helix/HelixInstanceDataManagerConfig.java#L160 ) - m
Mayank
04/04/2019, 12:43 AMah - c
Chinmay Soman
04/04/2019, 12:43 AMthat seems to be necessary here: - m
Mayank
04/04/2019, 12:43 AMWe can evaluate if the default should be true - c
Chinmay Soman
04/04/2019, 12:43 AMI'm curious, shoudl the default be true - c
Chinmay Soman
04/04/2019, 12:43 AMwhat are the implications ? - m
Mayank
04/04/2019, 12:45 AM@User ^^ - j
Jackie
04/04/2019, 12:47 AM@User If default column is enabled, when the data you pushed does not match the schema, we will automatically generate default values for the missing columns