LOG_CHECKPOINTS_TO_ALERT  parameter indicates whether to log the checkpoint information in the alert log or not.

LOG_CHECKPOINTS_TO_ALERT – > FALSE( défault value)

SQL> show parameter LOG_CHECKPOINTS_TO_ALERT

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_checkpoints_to_alert             boolean     FALSE


SQL> alter system checkpoint;

System altered.

ALERT LOG:
Tue Feb 26 03:35:55 2019
Thread 1 advanced to log sequence 6066 (LGWR switch)
Current log# 3 seq# 6066 mem# 0: /B2CNSM/oradata/B2CNSM/onlinelog/redo03.log
Tue Feb 26 03:35:55 2019
Archived Log entry 6069 added for thread 1 sequence 6065 ID 0x54d5ee59 dest 1:

We can see, despite doing checkpoint, no informations is written in alert log.

LOG_CHECKPOINTS_TO_ALERT – > TRUE 

SQL> alter system set log_checkpoints_to_alert=TRUE scope=both;

System altered.

SQL> show parameter LOG_CHECKPOINTS_TO_ALERT

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_checkpoints_to_alert             boolean     TRUE
SQL>  alter system checkpoint;

System altered.

ALERT LOG 

Tue Feb 26 13:33:33 2019
ALTER SYSTEM SET log_checkpoints_to_alert=TRUE SCOPE=BOTH;
Tue Feb 26 13:33:40 2019
Beginning global checkpoint up to RBA [0x17b2.126b2.10], SCN: 11904009889406
Completed checkpoint up to RBA [0x17b2.126b2.10], SCN: 11904009889406

Now checkpoint information is getting logged in the alert log .

NOTE – > This parameter has no impact on the database performance. It is just for additional checkpoint logging.