Frequency of archive log generation.

Find the frequency in which archive logs are generated for a database.

This will give the number of archive logs generated for each day.

SQL> select count(*),trunc(first_time) from v$log_history group by trunc(first_time) order by trunc(first_time);

  COUNT(*) TRUNC(FIR
---------- ---------
         2 05-APR-11
        44 06-APR-11
        42 07-APR-11
        42 08-APR-11
        43 09-APR-11
        43 10-APR-11
        42 11-APR-11
        45 12-APR-11
        43 13-APR-11
        43 14-APR-11
        43 15-APR-11

  COUNT(*) TRUNC(FIR
---------- ---------
        43 16-APR-11
        49 17-APR-11
        46 18-APR-11
        14 19-APR-11

15 rows selected.

If you want to know at what time log switches happened for each day, you can use the below query.

SQL> SELECT TO_CHAR(first_time,'YYYY-MON-DD') DAY,
  2    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'00',1,0)),'99') "00",
  3    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'01',1,0)),'99') "01",
  4    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'02',1,0)),'99') "02",
  5    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'03',1,0)),'99') "03",
  6    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'04',1,0)),'99') "04",
  7    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'05',1,0)),'99') "05",
  8    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'06',1,0)),'99') "06",
  9    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'07',1,0)),'99') "07",
10    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'08',1,0)),'99') "08",
11    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'09',1,0)),'99') "09",
12    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'10',1,0)),'99') "10",
13    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'11',1,0)),'99') "11",
14    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'12',1,0)),'99') "12",
15    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'13',1,0)),'99') "13",
16    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'14',1,0)),'99') "14",
17    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'15',1,0)),'99') "15",
18    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'16',1,0)),'99') "16",
19    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'17',1,0)),'99') "17",
20    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'18',1,0)),'99') "18",
21    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'19',1,0)),'99') "19",
22    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'20',1,0)),'99') "20",
23    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'22',1,0)),'99') "22",
24    TO_CHAR(SUM(DECODE(TO_CHAR(first_time,'HH24'),'23',1,0)),'99') "23"
25  FROM v$log_history
26  GROUP BY TO_CHAR(first_time,'YYYY-MON-DD')
27  ORDER BY TO_CHAR(first_time,'YYYY-MON-DD') ;

DAY         00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  22  23
----------- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
2011-APR-05   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   2
2011-APR-06   5   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  16
2011-APR-07   4   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  15
2011-APR-08   4   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  15
2011-APR-09   5   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  15
2011-APR-10   5   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  15
2011-APR-11   5   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  14
2011-APR-12   7   0   3   0   2   0   2   0   2   0   2   0   2   1   2   0   2   0   2   0   2   2  14
2011-APR-13   6   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  14
2011-APR-14   6   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  14
2011-APR-15   6   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  14

DAY         00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  22  23
----------- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
2011-APR-16   6   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  14
2011-APR-17   7   0   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  19
2011-APR-18   2   2   3   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   0   2   2  19
2011-APR-19   2   0   3   0   2   0   2   0   2   0   2   0   1   0   0   0   0   0   0   0   0   0   0

The retention period or the history of log switches / arvchive log generation in v$log_history is controlled by MAXLOGHISTORY. This is specified during database creation or control file creation.

You can query this as shown below.

SQL> select type,records_used  from v$controlfile_record_section where type like 'LOG%'
  2  ;

TYPE                         RECORDS_USED
---------------------------- ------------
LOG HISTORY                           584

SQL> select count(*) from v$log_history;

  COUNT(*)
----------
       584
      

Put files in remote machine by FTP in background

If you have a requirement to put files from one machine to a remote machine where the client in which you are connecting might disconnect after some time out. In this case you would want the file transfer to take place in background ( in server ).Here is a small shell script which can put files in background. This is for solaris.

#!/bin/sh
HOST='remote machine ip'
USER='remote machine user name'
PASSWD='remote machine user password'

ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
prompt off
cd /data1/oracle/rman -- source directory where your files are present
mput *
quit
END_SCRIPT
exit 0

You can check whether the process is running as shown below.

-bash-3.00$ ps -ef | grep scriptname