What the LGWR process writes in the disk before the DBWn flush the data?
I think that are a kind of "ids" (maybe the rowid?) of data blocks present in the header of the blocks, that the SMON uses to locate and exclude the "uncommited" data in ROLLFOWARD process.
The "private strand flush not complete" is a "noise" error, and can be disregarded because it relates to internal cache redo file management.
However this "private strand flush cannot complete" error is sometimes accompanies by a hung database.
These are quotes from MR Burleson himself .
But can this be really ignored as it's also mentioned "hung database"
Any solution for this scenario.
1)I have a master site and local site.
2)Materialized view is refreshed at local site... and the results are stored in a cache which Java uses .
3)Any request for the mview data is retrieved from cache.
4)Now I am refreshing matview again using fast refresh.. i.e only records that are changed in the master is updated at the local site.
5) I have to flush the cache .. while flushing i have to flush only those records that are changed.... coz full flush is not good and i have to re cache the entire data if i do full flush
My Question is How to identify the records that changed....so that I can only flush those records from cache. I want to identify the changed records.
Redo log information can be transmitted in one of two ways from the primary database to the standby database: either by ARCH or LGWR.
1. when ARCH involves
2. when LGWR involves
FAL_Client = (Should i enter net service name or Db name or service_name
FAL_Server = Should i enter net service name or Db name or service_name )
FAL_CLIENT='whichone'
[code]...
i am seeing (LGWR switch) happening in my databsae alert log every 3-4 minutes. is that appropriate? if not, what measure can i take to reduce this?
View 1 Replies View RelatedWe had an issue last week were we had a session with a very basic SQL query lock up the database, spiking the CPU at 100%. When you would kill the session, the lock would just jump to another session and so on. We finally had to restart the database since our clients were being kicked out. After the restart of the database, the LGWR ended up locking and held the CPU between 85-95%. The archive logs were switching every 5 minutes, when normally it would be every 45min. We spoke with Oracle Support, but they just ended up brushing the issue off and saying it was a hardware issue and were not able to provide any kind of backing to that.
View 4 Replies View RelatedI have configured data guard in the windows XP same server .It is not able to apply log to the Standby database.when I queried the following, I go the following erros..
sql>select message from v$dataguard_status where dest_id=2;
FAL[server, ARC0]: Error 12514 creating remote archivelog file 'STNDBY'
PING[ARCk]: Heartbeat failed to connect to standby 'STNDBY'. Error is 12528.
LGWR: I/O error 1089 archiving log 1 to 'STNDBY'
"ARCk: Attempting destination LOG_ARCHIVE_DEST_2 network reconnect (3113)
"
"ARCk: Destination LOG_ARCHIVE_DEST_2 network reconnect abandoned
"
PING[ARCk]: Error 3113 when pinging standby STNDBY.
"LNS: Closing remote archive destination LOG_ARCHIVE_DEST_2: 'STNDBY' (error 1089)
"
LGWR: Error 1041 closing archivelog file 'STNDBY'
************************************************
Also if
SQL> select sequence#,applied from v$archived_log;
query gives the following message----
SEQUENCE# APP
---------- ---
7 YES
5 NO
8 NO
9 NO
6 NO
10 NO
10 NO
11 NO
11 NO
12 NO
12 NO
its possible to have multiple LGWR processes for a single database.If its possible how does the multiple processes write from redo log buffer to online redo log file.
View 3 Replies View RelatedI have few queries regarding standby database.
1)On primary Database Standby Redo log is required for switchover and on standby database Standby Redo log is required for
--Real time Apply
--Maximum protection or Maximum availability
Am I correct?
2)My database is in Maximum Performance mode. I set up following entry on init.ora:
LOG_ARCHIVE_DEST_2='service=standby LGWR ASYNC'. My question is do I need to have STANDBY Redo log file on standby database in order to use LGWR transport (LGWR ASYNC)mode from primary? Without Standby redo log on standby database can it transport redo data from primary to standby using LGWR transport mode (LGWR ASYNC)?
3)I have changed from the "ARCH" attribute to "LGWR" attribute of the LOG_ARCHIVE_DEST_n initialization parameter. But I have not changed the protection mode. I would like to know whether is there any impact in the behavior of the database, if we do not change the mode from "MAXIMUM PERFORMANCE" to "MAXIMUM AVAILABILITY"?
In statspack I find a lot of wait events "ARCH wait on SENDREQ". The database is configured with the LGWR ASYNC attribute. In the documentation I can read that the "ARCH wait"-events may happen in case the database is configured with the ARCH attribute.How is it possible I get these "ARCH wait"-envents and do these wait events have any effect on the "on line" performance of the database? Is it possible that a user that saves data in the database has to wait for thest "ARCH wait"-events?
View 1 Replies View Related