Solution : https://service.sap.com/sap/support/notes/339126 (SAP Service marketplace login required)
Key words : 
system displays runtime error 'dbif_rsql_internal_error', 'db requests -> terminated' function, terminated conversions continue automatically, symptom table conversions terminate, 'dbif_rsql_internal_error' short dump occurred, terminated table conversions, temporary table names, accompanying work process, call transaction se14, dbif_rsql_internal_error reason
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