Book Image

Oracle 10g/11g Data and Database Management Utilities

Book Image

Oracle 10g/11g Data and Database Management Utilities

Overview of this book

Does your database look complicated? Are you finding it difficult to interact with it? Database interaction is a part of the daily routine for all database professionals. Using Oracle Utilities the user can benefit from improved maintenance windows, optimized backups, faster data transfers, and more reliable security and in general can do more with the same time and resources.
Table of Contents (18 chapters)
Oracle 10g/11g Data and Database Management Utilities
Credits
About the Author
About the Reviewer
Preface

Loss of redo log files


The redo log files are written by the background process Log Writer(LGWR) with the information stored at the log buffer. If the log files are not available the process gets stuck, the transactional activity in the database is frozen and an error message is written to the alert.log file (ORA-00313: open failed for members of log group ## of thread ##), as shown in the next screenshot.

When a loss of redo log files occurs there are two different scenarios which depend on the status of the lost redo log. If the lost redo log had the status of inactive it is not critical. It is just enough to logically remove the group and rebuild it. On the other hand, if the status of the lost redo log file was CURRENT, then the situation may get complicated as the CURRENT status means the redo log was at that time written by the LGWR process, and the DB Writer(DBWR) process had not yet synchronized the datafiles by writing the dirty blocks from the DB buffer cache to the datafiles...