How to avoid SQLCODE=-968, SQLSTATE=57011 "The file system is full" error with merge statement
Assuming the merge statement needs to use some amount of temp table size, you should increase the file system size where the related user temporary tablespace resides.

To check the path of user temporary tablespace,


check db2diag message that may indicate which file system is related.
And also, db2pd -db &lt;dbname&gt; -tablespace


You may add new user temp tablespace on new path that has enough space for the same page size of related tables.