Solution : https://service.sap.com/sap/support/notes/1035137 (SAP Service marketplace login required)
Summary :
High fill levels in the PSAPUNDO tablespace have been noticed, due largely to Oracle 10g's Automatic Undo Management (AUM) feature, which promises not to overwrite undo information from completed transactions. This feature can lead to potential maxing of the UNDO_TABLESPACE if the retention settings do not account for current system activity and space constraints. For tablespaces set with AUTOEXTEND=OFF, the system bypasses specified UNDO_RETENTION settings, autonomously calculating an optimal, probably higher retention time using 85% of the actual space. Conversely, with AUTOEXTEND=ON, Oracle respects the minimum retention period unless space runs out, auto-expanding the tablespace or overriding older unexpired undo logs if the space is at maximum capacity. The recommendation for SAP systems using Oracle is to manage UNDO_TABLESPACE with AUTOEXTEND options prudently, either fixed-size or self-extending with constrained MAXSIZE parameters.
Key words :
terms psapundov$undostatv$rollstatv$transactiondba_undo_extentsdba_hist_undostatundo_managementundo_tablespaceundo_retentiondba_lobs reason, automatic undo managementsql> show parameter undodisplaying, undo tablespace>undo_retention=<undo retention period, 'yyyy-mon-dd hh24, fix sizethe system ignores, maximal file size limited, solution automatic undo management, lob segments automatic tuning, oracle database release 10g, automatic undo management
Related Notes :
| 828268 | Oracle Database 10g: New functions |
| 600141 | Oracle9i: Automatic UNDO Management |