David Wayne Birdsall commented on TRAFODION-2282:

See JIRA TRAFODION-882 for a related problem.

> Optimizer histogram cache is sometimes never refreshed
> ------------------------------------------------------
>                 Key: TRAFODION-2282
>                 URL: https://issues.apache.org/jira/browse/TRAFODION-2282
>             Project: Apache Trafodion
>          Issue Type: Bug
>          Components: sql-cmp
>    Affects Versions: 2.1-incubating
>         Environment: All
>            Reporter: David Wayne Birdsall
>            Assignee: David Wayne Birdsall
>             Fix For: 2.1-incubating
> Here's the scenario:
> In session 1, create a table T1 and populate it with, say, 200000 or more 
> rows.
> In session 2, prepare a query that selects from T1. For example, select 
> A,COUNT(*) FROM T1 GROUP BY A. The query should compile fine, but you should 
> see missing statistics warning messages (warning codes 6007 and 6008).
> In session 1, do "update statistics for table t1 on every column"
> In session 2, prepare other queries over a period of time. What should happen 
> is that after about an hour, the Optimizer decides to refresh the histograms. 
> However, due to a bug, it might never do so. So, the missing statistics 
> warnings (6007, 6008) never go away. Worse, the prepares never benefit from 
> the statistics so plan choice may be poor.

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