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Docs: Fix column name in ingestion rollup doc (#12036)
Fix the referred column name from "count" to "num_rows" as "count" vs. "COUNT(*)" might be a little confusing in this example.
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kfaraz committed May 10, 2022
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@@ -40,10 +40,10 @@ If you have conflicting needs for different use cases, you can create multiple t

## Maximizing rollup ratio

To measure the rollup ratio of a datasource compare the number of rows in Druid (`COUNT`) with the number of ingested events. For example, run a [Druid SQL](../querying/sql.md) query where "count" refers to a `count`-type metric generated at ingestion time as follows:
To measure the rollup ratio of a datasource, compare the number of rows in Druid (`COUNT`) with the number of ingested events. For example, run a [Druid SQL](../querying/sql.md) query where "num_rows" refers to a `count`-type metric generated at ingestion time as follows:

```sql
SELECT SUM("cnt") / (COUNT(*) * 1.0) FROM datasource
SELECT SUM("num_rows") / (COUNT(*) * 1.0) FROM datasource
```
The higher the result, the greater the benefit you gain from rollup. See [Counting the number of ingested events](schema-design.md#counting) for more details about how counting works with rollup is enabled.

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