RATIO_TO_REPORT is a very handy and useful function. Before going through what it does, let’s first look at this example:

```
SELECT last_name, salary,
ROUND (salary / SUM (salary) OVER () * 100,
2
) percent_of_total
FROM employees
WHERE job_id = 'PU_CLERK'
ORDER BY last_name;
```

Returns:

```
LAST_NAME SALARY PERCENT_OF_TOTAL
------------------------- ---------- --------------------------------------
Baida 2900 20.86
Colmenares 2500 17.99
Himuro 2600 18.71
Khoo 3100 22.3
Tobias 2800 20.14
5 row(s) retrieved
```

The *percent_of_total* column represents the salary for each employee as a percentage of the total salary paid to all clerks. The above query can also be re-written using the RATIO_TO_REPORT SQL function:

```
SELECT last_name, salary,
ROUND
(ratio_to_report (salary) OVER () * 100,
2
) AS percent_of_total
FROM employees
WHERE job_id = 'PU_CLERK'
ORDER BY last_name
```

Both queries return the same output.

Oracle documentation definition: The RATIO_TO_REPORT function computes the ratio of a value to the sum of a set of values. Its syntax is:

RATIO_TO_REPORT ( expr ) OVER ( [query_partition_clause] )

In this, the following applies:

*expr*can be any valid expression involving column references or aggregates.The PARTITION BY clause defines the groups on which the RATIO_TO_REPORT function is to be computed. If the PARTITION BY clause is absent, then the function is computed over the whole query result set.

Finally, Tom Kyte used the RATIO_TO_REPORT function to calculate the percentage of each browser hitting his blog and to calculate the percentage of his posts per month. Sergio Leunissen used the RATIO_TO_REPORT function as a basis for an APEX (HTML DB) report.

SQL Analytic functions are simple and powerful.

Filed in Oracle, Tips on 14 Jun 06 | Tags: analytic, function, sql

Karl| 20 Mar 2007 6:44 amHi Eddie; used it today the first time! Karl

Tshepo| 03 Sep 2008 12:11 amUsing the query below, I need to calculate ratio of paper to electronic claims. Pls help

select practice_fk as ‘Prac_No1′, p.doc_short_descr as ‘Prac_Name1′, DS.dsp_ind, accreditation, accred_level, SUM(isnull(convert(numeric,(1)),0)) as ‘Total_Claims’, SUM(CASE WHEN convert(numeric,trade_fk) 0 THEN 1 ELSE 0 END) as ‘EDI’, SUM(CASE WHEN convert(numeric,trade_fk) = 0 THEN 1 ELSE 0 END) as ‘Paper’

from ( select c.claim_fk,c.trade_fk,c.practice_fk,c.rcvd_date from tf_claim C with (nolock) where benefit_amt >= 0.05 AND practice_type IN (14,15,50,51) AND convert(datetime,convert(varchar,claim_dt),112) BETWEEN ’1 MAY 2008′ AND ’31 AUG 2008′ group by c.claim_fk,c.trade_fk,c.practice_fk,c.rcvd_date ) CLAIM LEFT JOIN td_practice P with (nolock) ON (practice_pk = practice_fk) LEFT JOIN pcdw2.dw_staging.dbo.tsd_dsp ds ON (ds.practice_pk = claim.practice_fk) LEFT JOIN dbo.td_negotiation2 n on (n.negotiation_pk = ds.neg_num)

Where DS.dsp_ind = ‘DSP’

group by practice_fk, p.doc_short_descr,ds.dsp_ind,accreditation, accred_level

Sergio| 24 Oct 2008 9:02 amHi Eddie,

I googling for ratio_to_report and came across your post. I noticed it links to an old blog post of mine. orablogs.com kicked the bucket a long time ago. FWIW, I revived this post on my new blog:

http://blogs.oracle.com/sergio/2008/10/quick_and_dirty_inline_charts_1.html

Sergio

Eddie Awad| 24 Oct 2008 10:28 amThanks Sergio, I have updated my post with your new URL.