SQL & PL/SQL

Hi guys,

Please give an advise about what I am missunderstanding in following issue I have.

Database version:

SQL>SELECT banner FROM v$version;
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
"CORE 11.2.0.1.0 Production"
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

The issue I have is...

I don't understand why the following query,

SELECT limit_
      ,current_usage
      ,maximum_limit
      ,pct_max_limit
      ,ROUND(current_usage*100/maximum_limit) pct_used
FROM
(
   SELECT 'DB Sessions' limit_, p.cnt maximum_limit, c.cnt current_usage, 85 pct_max_limit
   FROM (SELECT TO_NUMBER(value) cnt FROM v$parameter WHERE name = 'sessions') p
       ,(SELECT COUNT(*) cnt FROM v$session) c
   UNION ALL
   SELECT 'DB Processes' limit_, p.cnt maximum_limit, c.cnt current_usage, 85 pct_max_limit
   FROM (SELECT TO_NUMBER(value) cnt FROM v$parameter WHERE name = 'processes') p
       ,(SELECT COUNT(*) cnt FROM v$process) c
   UNION ALL
   SELECT 'DB Files' limit_, p.cnt maximum_limit, c.cnt current_usage, 85 pct_max_limit
   FROM (SELECT TO_NUMBER(value) cnt FROM v$parameter WHERE name = 'db_files') p
       ,(SELECT SUM(cnt) cnt FROM (SELECT COUNT(*) cnt FROM v$datafile
                                   UNION ALL
                                   SELECT COUNT(*) cnt FROM v$tempfile
                                  )
        ) c
   UNION ALL
   SELECT 'ASM DiskGroups' limit_, p.cnt maximum_limit, c.cnt current_usage, 85 pct_max_limit
   FROM (SELECT 63 cnt FROM dual) p /*ASM Storage Limits 11gr2*/
       ,(SELECT COUNT(*) cnt FROM v$asm_diskgroup) c
   UNION ALL
   SELECT 'ASM Disks' limit_, p.cnt maximum_limit, c.cnt current_usage, 85 pct_max_limit
   FROM (SELECT 10000 cnt FROM dual) p /*ASM Storage Limits 11gr2*/
       ,(SELECT COUNT(*) cnt FROM v$asm_disk) c
)
--WHERE
;
;

that returns in my DEV environment the following ouput

When I put the following WHERE clause

WHERE ROUND(current_usage*100/maximum_limit) >= 85

Returns the following error (alse tested in 11.2.0.3):

ORA-01476: divisor is equal to zero
01476. 00000 -  "divisor is equal to zero"
*Cause:    
*Action:

I am totally lost in this .....

Can you help me please?

Thanks in advance.

Regards,

Juan M