I checked SPACE information recorded in CATALOG via DB2 Admin tool, and I found that TS (SPACE in SYSIBM.SYSTABLESPACE) and the only table in it (SPACEF in SYSIBM.SYSTABLES) has different value showed. There is no index or other objects defined in this tablespace.
Though this may not related, I am sure that the REORG and RUNSTATS had been ran recently on the TS.
Please advise why different space information showed. Thanks!
Analysis of the values in a SPACE or SPACEF column
The value in a SPACE or SPACEF column represents total allocated space, not only the space that is allocated on the current list of volumes in the storage groups. If the value is too large to fit in the SPACE column, the SPACEF column is used.
You can delete volumes from a storage group even though space on those volumes is still allocated to DB2® table spaces or indexes. Deletion of a volume from a storage group prevents future allocations; it does not withdraw a current allocation