====== InfluxDB ======

===== Concepts =====

InfluxDB is a time series database. The official documentation provides all necessary information for using this special kind of database.


The **[[https://docs.influxdata.com/influxdb/v1.7/concepts/key_concepts/|key concepts]]** section explains the basic terms

  * database
  * measurement
  * timestamp
  * series
  * point
  * field
    * field key
    * field value
    * field set
  * tag
    * tag key
    * tag value
    * tag set
  * retention policy


For relational database users:

tags are like key attributes inducing index creation. The only attribute type for tags is string. Fields are not indexed but can be of four different types: float, integer, string, Boolean.

 





===== Download and install NOAA sample data =====

  * https://docs.influxdata.com/influxdb/v1.7/query_language/data_download/

<code bash create_and_fill_NOAA_water_db.sh>

# rb: 2019-07-09
# BASH shell script, 
# copied from https://docs.influxdata.com/influxdb/v1.7/query_language/data_download/

# open influx
influx -precision rfc3339 -execute 

</code>

===== Data Exploration, Select =====

https://docs.influxdata.com/influxdb/v1.7/query_language/data_exploration/


===== Common Commands =====

<code>

show databases

use NOAA_water_database

show measurements

SELECT COUNT("water_level") FROM h2o_feet

SELECT * FROM h2o_feet LIMIT 5

show series

show tag keys

show field keys



create database bla

use bla

show measurements

drop database bla

</code>