Crashes by merge statements with identical source and target tables

Detail name	Value
Changelog Number	7627
Type	Bug
Status	Resolved
Affected Versions	Exasol 6.1.0
Fix Versions	Exasol 6.1.3
Resolution Date	2019-03-11

Problem Description

If certain conditions are met the merge statements crashes with an "Internal server error" message and an associated coredump is generated. For this to occur all of the following conditions must be met:

• Multiple node cluster
• The source and the target table are identical
• The merge statements contains an update clause
• The join in the merge is global (the table has no distribution keys set on the join columns)

Sample query

merge into t a using t b  -- same source and destination table
    on a.j=b.j 
    when matched then update set a.i = b.i;