11G DATAGUARD的理解

Deprecated Attributes for LOG_ARCHIVE_DEST_n

LOG_ARCHIVE_DEST_n已棄用的屬性，ARCH和LGWR已經被SYNC和ASYNC替代掉了

The following attributes are deprecated for the LOG_ARCHIVE_DEST_n parameter. They are retained for backward compatibility only.

 

In addition, note the following changes to the ASYNC and SYNC attributes:

■ The BLOCKS keyword on the ASYNC attribute is no longer needed.

It is no longer necessary to set this keyword because Data Guard dynamically adjusts the block count up or down to an appropriate number of blocks, as necessary.

■ The PARALLEL and NOPARALLEL keywords on the SYNC attribute are no longer needed.

 另外，請注意以下對ASYNC和SYNC屬性的更改:

■不再需要ASYNC屬性上的BLOCKS關鍵字。
不需要設定此關鍵字，因為Data Guard會根據需要將塊數上限或下調動態調整到適當數量的塊。
■不再需要SYNC屬性上的PARALLEL和NOPARALLEL關鍵字。

FAL_CLIENT引數在11G中已經廢棄了
The FAL_CLIENT database initialization parameter is no longer required.

11G流程圖的解釋
1、主庫commit等觸發lgwr寫redo buffer到online redo logs的同時觸發LNSn傳輸redo buffer到備庫的RFS
主庫：online redo logs-->arch-->archived redo log
備庫有standby redo log且啟用real-time apply：RFS-->standby redo log-->MRP-->database
備庫有standby redo log沒有啟用real-time apply：RFS-->standby redo log-->archvied redo log-->MRP-->database
備庫沒有standby redo log：RFS-->archvied redo log-->MRP-->database

2、主庫commit等觸發lgwr寫redo buffer到online redo logs的同時觸發LNSn傳輸online redo logs到備庫的RFS
主庫：online redo logs-->arch-->archived redo log
備庫有standby redo log且啟用real-time apply：RFS-->standby redo log-->MRP-->database
備庫有standby redo log沒有啟用real-time apply：RFS-->standby redo log-->archvied redo log-->MRP-->database
備庫沒有standby redo log：RFS-->archvied redo log-->MRP-->database

3、主庫commit等只觸發lgwr寫redo buffer到online redo logs，主庫只觸發online redo logs歸檔
備庫：RFS透過fal_server引數去找主庫的ARCH，主庫的ARCH直接傳輸主庫的archived redo log到備庫的RFS
備庫有standby redo log：RFS-->主庫ARCH-->RFS->standby redo log-->archvied redo log-->MRP-->database
備庫沒有standby redo log：RFS-->主庫ARCH-->RFS-->archvied redo log-->MRP-->database

主庫的alert日誌資訊有LNS程式的資訊
LNS: Standby redo logfile selected for thread 1 sequence 16 for destination LOG_ARCHIVE_DEST_2

備庫的alert日誌資訊有RFS、MRP程式的資訊
RFS[1]: Selected log 5 for thread 1 sequence 13 dbid 1481430707 branch 953739056
MRP0 started with pid=35, OS id=28759
MRP0: Background Managed Standby Recovery process started (orcl)