Before Oracle 10.2g if we need to change the limit of MAXLOGFILE, MAXLOGMEMBERS, MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES then the possible solutions is either RE-create new controlfile or create a new database.
But from Oracle 10.2g all sections of the control file are now automatically extended when they run out of space. This means that there is no longer a requirement to re-create the control file when changes in the configuration parameter the MAXLOGFILE, MAXLOGMEMBERS, MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES are needed.
Two different Sections of Control file:
--------------------------------------------
1)Circularly reusable Sections:
The CONTROL_FILE_RECORD_KEEP_TIME specifies the minimum number of days before a reusable record in the control file can be reused. Example of circularly reusable records are archive log records and various backup records.
2)Not circularly reusable Sections:
Records such as datafile, tablespace, and redo thread records, which are never reused unless the corresponding object is dropped from the tablespace.
For the circularly reusable sections the behaviour remain same with previous version.
The new feature in Oracle 10.2g is that for the non-reusable records we now also extend the control file size if we go over the previous limit.
Though the values for MAXLOGFILE, MAXLOGMEMBERS,MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES are still useful since they initialize the control file at a certain size, but they no longer set a hard limit for the number of records in the control file.
Therefore 10.2g onwards, we can get rid of re-creating controlfile whenever we need change parameter like MAXLOGFILE, MAXLOGMEMBERS,MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES and keep the database alive.
Related Documents:
----------------------
How and When to Re-create Controlfile
No comments:
Post a Comment