Influxdb: Question on 0.9x: How to edit measurements data ?

[dtouzeau]

What is the best way to edit a measurement in SQL ?
I know that the "UPDATE" command is not available but how to do it ?
i have a "serie" called access_log using strings:
time, website,category,username,MAC
how to update a field like:
UPDATE access_log SET username='something' WHERE MAC='64:b8:53:0f:a1:8d'

[ericjmiller]

I usually create a json with 'time' and 'sequence_number' the exact same as the data point I want to update and add the new data. Then submit via HTTP API (python bindings). This replaces data in the series. There may be a better way.

[otoolep]

Any point in the system is uniquely defined by:

• the database.
• retention policy.
• measurement name.
• timestamp.
• tag key and values (if any).

If you send a point into the system, and a point already exists with those exact attributes, the point on disk will be overwritten. If it does not exist, it will be inserted.

@ericjmiller -- are you using a field or a tag for your "sequence" number? You should know that if it is a tag, that may have a very significant performance impact.

http://influxdb.com/docs/v0.9/concepts/schema_and_data_layout.html#tags-and-cardinality

[otoolep]

I believe this is answered, closing this, though the mailing list is the preferred place for questions. Github issues are really only for bug reports and feature requests.

[dtouzeau]

So my feature requests is to explain or point to the right place for the best way to do it here:
https://github.com/influxdb/influxdb/blob/master/QUERIES.md

[beckettsean]

@otoolep I believe @ericjmiller is likely on 0.8.x, which had an internal sequence number. The behavior is the same in 0.8 and 0.9, in that a newly written point will silently overwrite a previous point. In 0.8 the uniqueness of a point is determined by the series name, the timestamp, and the sequence number. In 0.9 the uniqueness of a point is determined by the measurement, the timestamp, and the tag set.

@dtouzeau thank you for your request to improve the documentation. I'll take this as an issue for the queries.md page, but please open further documentation requests on the influxdb/influxdb.org repo.