# [26ai] ALERT_LOG_MAX_SIZE

*If you prefer to read in Spanish* [***Spanish version***](https://dbaenlasombra.com/26ai-alert-log-max-size)*.*

Today, let's talk about a new parameter in 26ai in order to handle the size our alert log in a straightforward and efficient way. It's **alert\_log\_max\_size** parameter.

The default value is 1000Mb:

```sql
SQL>
SQL> show parameter alert_log_max_size

NAME               TYPE        VALUE
------------------ ----------- -------
alert_log_max_size big integer 1000M

SQL>
```

How does Oracle handle it? Oracle splits the **alert log** in segments of 50Mb. In other words, we'll have 20 files of 50Mb each.

The parameter can only be modified at the CDB$Root, not at the PDB:

```sql
SQL> ALTER SYSTEM SET ALERT_LOG_MAX_SIZE = 150M; 

ALTER SYSTEM SET ALERT_LOG_MAX_SIZE = 150M 
* 
ERROR at line 1: ORA-65040: Operation is not allowed from within a pluggable database.
```

Let's write some information into the **alert log** in order to see how Oracle works:

```sql
[oracle@~]cat save_inf.sql
begin 
declare 
 i number := 0; 
 begin 
  loop i := i + 1; 
  sys.dbms_system.ksdwrt(2, 'string(''L'',?)= ' || dbms_random.string('L',trunc(dbms_random.value(10,21)))); 
 exit when i >= 10000000; 
end loop; 
end; 
end; 
/
[oracle@~] 
 watch -n 10 "sqlplus -s / as sysdba @save_inf.sql"
[oracle@l23ai alert]$ ls -lash *xml 
51M -rw-r----- 1 oracle asmdba 51M Apr 2 18:11 log_1.xml 
51M -rw-r----- 1 oracle asmdba 51M Apr 2 18:11 log_2.xml 
46M -rw-r----- 1 oracle asmdba 46M Apr 2 18:11 log.xml
```

As we can see, our **alert log** has been split in files of 50Mb each!.

A quick note about the new parameter, if we set it to zero value, then, the **alert log** can grown indefinitely.

But, can we modify the value of 50Mb? Of course. There is a hidden parameter, it's "**\_alert\_segment\_size**" that allows us to change that value.

```sql
SQL> ALTER SYSTEM SET "_alert_segment_size" = 30;
System altered.

SQL> show parameter "_alert_segment_size"

NAME               TYPE        VALUE
------------------ ----------- -------
_alert_segment_size integer     30

[oracle@l23ai ~]$ 
 watch -n 10 "sqlplus -s / as sysdba @save_inf.sql"
[oracle@l23ai alert]$ ls -lash *xml 
51M -rw-r----- 1 oracle asmdba 51M Apr 2 18:11 log_1.xml 
51M -rw-r----- 1 oracle asmdba 51M Apr 2 18:11 log_2.xml 
46M -rw-r----- 1 oracle asmdba 46M Apr 2 22:10 log_3.xml 
31M -rw-r----- 1 oracle asmdba 31M Apr 3 09:11 log_4.xml 
31M -rw-r----- 1 oracle asmdba 31M Apr 3 09:11 log_5.xml 
4.9M -rw-r----- 1 oracle asmdba 4.9M Apr 3 09:11 log.xml
```

Looking forward to seeing you in the next article :)