oracle dataguard standby log_archive_dest_state_n 中defer 含義

The LOG_ARCHIVE_DEST_STATE_n parameters (where n = 1, 2, 3, ... 10) specify the availability state of the corresponding destination. The parameter suffix (1 through 10) specifies one of the ten corresponding LOG_ARCHIVE_DEST_n destination parameters.

Values:

• enabled

  Specifies that a valid log archive destination can be used for a subsequent archiving operation (automatic or manual). This is the default.

• defer

  Specifies that valid destination information and attributes are preserved, but the destination is excluded from archiving operations until re-enabled.

• alternate

  Specifies that a log archive destination is not enabled but will become enabled if communications to another destination fail.

The LOG_ARCHIVE_DEST_STATE_n parameters have no effect on the ENABLE state for the LOG_ARCHIVE_DEST or LOG_ARCHIVE_DUPLEX_DEST parameters.

The V$ARCHIVE_DEST dynamic performance view shows values in use for the current session. The DEST_ID column of that view corresponds to the archive destination suffix n.