Oracle Error Codes

(MAINTCHK01) You cannot string values of dimension workspace object during a loop over it.

User tried to insert or delete a value of the specified dimension while some loop over that dimension was active. The loop could be an explicit FOR or ACROSS loop, or a natural expression evaluation or OLAP_TABLE loop. Also, it could be a loop over the dimension itself or over a derived dimension (like a composite or partition template) or dimension alias that includes it. The insert or delete could be explicitly caused by the MAINTAIN command. It is also possible that the user attempted to assign a value to a variable or partition dimensioned by a composite during a loop over that composite using a qualified data reference (QDR), and that the exception was generated by the engines attempt to insert a new position in the composite to hold the new value.

How to Solve :

Move the dimension maintenance or QDR-based variable assignment outside the dimension loop.