[GitHub] [trafodion] DaveBirdsall opened a new pull request #1821: [TRAFODION-3291] Fix core when multi-column stats are done on lots of columns

[GitBox <gi...@apache.org>]

DaveBirdsall opened a new pull request #1821: [TRAFODION-3291] Fix core when multi-column stats are done on lots of columns
URL: https://github.com/apache/trafodion/pull/1821
 
 
   The problem given in the JIRA is that creating a multi-column histogram on 500 columns results in a tdm_arkcmp core.
   
   There are two changes in this change set:
   
   1. Fixes the core by addressing a buffer overrun problem. When we log messages, we use a fixed size buffer for the message text. When a column list is long enough, we were overrunning this buffer, causing the core. The fix truncates the column list text to avoid these overruns.
   
   2. Adds a limit on the number of columns in a multi-column histogram. As a practical matter, they are not useful on large column sets. Too, the request could conceivably be a syntax mistake by the user; it may be the user intended to specify a list of columns to create single column histograms upon. The limit is set at 10 (we already have such a limit when automatically generating multi-column histograms for key prefixes). It can be overridden using CQD USTAT_MULTI_COLUMN_LIMIT.

----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
 
For queries about this service, please contact Infrastructure at:
users@infra.apache.org


With regards,
Apache Git Services