# Best practices around database/retention policy/measurement design

**URL:** <https://community.influxdata.com/t/best-practices-around-database-retention-policy-measurement-design/1147>\
**Category:** Systems\
**Tags:** influxdb, schema, backup\
**Created:** [June 1, 2017, 10:57am UTC](https://community.influxdata.com/t/best-practices-around-database-retention-policy-measurement-design/1147 "2017-06-01T10:57:40Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![jackzampolin](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/jackzampolin/32/5_2.png) [@jackzampolin](https://community.influxdata.com/u/jackzampolin)\
**Post date:** [June 1, 2017, 5:13pm UTC](https://community.influxdata.com/t/best-practices-around-database-retention-policy-measurement-design/1147/2 "2017-06-01T17:13:25Z")

</div>

@dm3

1. You loose the ability to query it together. If it has a similar schema then writing it all to the same measurement will allow you to correlate the data. In that situation you would distinguish the data sources with a tag (`source=foo`).
2. Nope!
3. You can think of measurements as tables in SQL, tags as indexed columns, and fields as unindexed columns. Does this help?
4. This should work for you. Give it a test though. We made some backup changes for the 1.2 release so make sure you are using the latest.

---

_[View the full topic](https://community.influxdata.com/t/best-practices-around-database-retention-policy-measurement-design/1147)._