Dba_rollback_segs

Oracle Undo: Check Extent Status in DBA_UNDO_EXTENTS Purpose A report query runs for forty minutes on a busy system and ends with ORA-01555: snapshot too old. The query is correct. The undo it needed to build a consistent picture of the data was overwritten before the query finished. Somewhere between the size of the …

Understanding Rollback Segments in Oracle Databases Rollback segments are essential components of Oracle databases, providing a mechanism to reverse uncommitted transactions and maintain data consistency. This post presents a SQL query for inspecting rollback segments, as well as explanations and insights into their …