[Info-ingres] same select statement returns different results when repeatedly executed

[Tim]

On Tuesday, September 23, 2014 7:41:27 PM UTC+1, droesler wrote:
> what should I be looking for to resolve this? 

Try Optimizedb.  We saw this in a situation where a lot of records were added to a table outside of the range of the index when optimizdeb last ran.  Rerunning optimizedb (or dropping statistics) allowed the query to run successfully.  Turning off Parallel Query may also help?
(We were attempting to delete all the matching rows, but several were left behind  - this was bug 126831 - fixed in patch 14700, so may not be exactly the same?)