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fixed note block (#2960)

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Scott Anderson 2021-08-02 11:01:52 -06:00 committed by GitHub
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content/influxdb/v1.8/concepts/key_concepts.md
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@ -118,19 +118,22 @@ Avoid using the following reserved keys:
If reserved keys are included as a tag or field key, the associated point is discarded.
> **Why indexing matters: The schema case study**
{{% note %}}
#### Why indexing matters: The schema case study
> Say you notice that most of your queries focus on the values of the field keys `honeybees` and `butterflies`:
Say you notice that most of your queries focus on the values of the field keys `honeybees` and `butterflies`:
> `SELECT * FROM "census" WHERE "butterflies" = 1`
> `SELECT * FROM "census" WHERE "honeybees" = 23`
```sql
SELECT * FROM "census" WHERE "butterflies" = 1
SELECT * FROM "census" WHERE "honeybees" = 23
```
> Because fields aren't indexed, InfluxDB scans every value of `butterflies` in the first query and every value of `honeybees` in the second query before it provides a response.
Because fields aren't indexed, InfluxDB scans every value of `butterflies` in the first query and every value of `honeybees` in the second query before it provides a response.
That behavior can hurt query response times - especially on a much larger scale.
To optimize your queries, it may be beneficial to rearrange your [schema](/influxdb/v1.8/concepts/glossary/#schema) such that the fields (`butterflies` and `honeybees`) become the tags and the tags (`location` and `scientist`) become the fields:
> **name:** <span class="tooltip" data-tooltip-text="Measurement">census</span>
>
**name:** <span class="tooltip" data-tooltip-text="Measurement">census</span>
| time | <span class ="tooltip" data-tooltip-text ="Field key">location</span> | <span class ="tooltip" data-tooltip-text ="Field key">scientist</span> | <span class ="tooltip" data-tooltip-text ="Tag key">butterflies</span> | <span class ="tooltip" data-tooltip-text ="Tag key">honeybees</span> |
| ---- | --------------------------------------------------------------------- | ---------------------------------------------------------------------- | ---------------------------------------------------------------------- | -------------------------------------------------------------------- |
| 2015-08-18T00:00:00Z | 1 | langstroth | 12 | 23 |
@ -142,7 +145,8 @@ To optimize your queries, it may be beneficial to rearrange your [schema](/influ
| 2015-08-18T06:06:00Z | 2 | perpetua | 8 | 23 |
| 2015-08-18T06:12:00Z | 2 | perpetua | 7 | 22 |
> Now that `butterflies` and `honeybees` are tags, InfluxDB won't have to scan every one of their values when it performs the queries above - this means that your queries are even faster.
Now that `butterflies` and `honeybees` are tags, InfluxDB won't have to scan every one of their values when it performs the queries above - this means that your queries are even faster.
{{% /note %}}
The <a name=measurement></a>_**measurement**_ acts as a container for tags, fields, and the `time` column, and the measurement name is the description of the data that are stored in the associated fields.
Measurement names are strings, and, for any SQL users out there, a measurement is conceptually similar to a table.