Finding TAG (VALUE) insertion time

InfluxDB 2 Dashboards
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1

Hi All,

Is there an option to find the time stamp when new tag value is inserted into the database. E.g. Using the below query I can view the “TAG” values

show tag values from with key = “TAGName” where

The output gives me the TAG Values but wondering if there is an option to view the timestamps associated with first tag entry?

2

Can you be more specific about what you’re querying?

In a simple WHERE clause, the timestamps are returned.

For example, selecting data with specific tag key-values:

SELECT “water_level”
FROM “h2o_feet”
WHERE “location” = ‘santa_monica’

name: h2o_feet

time water_level
2015-08-18T00:00:00Z 2.064
2015-08-18T00:06:00Z 2.116
[…]
2015-09-18T21:36:00Z 5.066
2015-09-18T21:42:00Z 4.938

Are you looking to get just the timestamp of the first entry?

3

Thanks Katy for the reply,

I’m looking for a query which can get me the following

  1. Tag key-value
  2. When the tag with the key-value was created (or first seen in the system)
4

Okay, I think I understand now.

SHOW TAG VALUE WITH KEY = "abc" is something we call a meta query. Unlike regular queries it doesn’t actually query the data that we have stored with timestamps
There are a whole bunch of them, and they (almost exclusively) only talk to the index, which doesn’t contain timestamp information.

I don’t think we currently support returning timestamps on meta queries.

You can check out the docs on meta queries for a little more detail.

5

how about use subquery? instead of show tag values
like this

# show tag values from with key = “TAGName” where condition
select TagName from (select field, TagName from Measurement where condition)

it return timestamp with tag values