influxdb.md

InfluxDB

InfluxDB is a great reference for tsdb-ql

TODO

• infux shell does not support tab complete influxdata/influxdb#7704
• infux ql said you can't distinguish field and tag

Background

• It uses Extend Backus-Naur form which is also what golang uses

Install

• Download binary from https://www.influxdata.com/downloads/#influxdb
• Extract and put the bin folder in path, i.e. export PATH=$PATH:$HOME/app/influxdb/usr/bin
• run influxd to start the daemon
• run influx to enter interactive shell or import data
• TODO: figure out where the disk data is stored

Query Language

The entry can be found in https://docs.influxdata.com/influxdb/v1.2/query_language/

• curl https://s3.amazonaws.com/noaa.water-database/NOAA_data.txt -o NOAA_data.txt
• SELECT COUNT(water_level) FROM h2o_feet
• SELECT * FROM h2o_feet LIMIT 5
• InfluxQl Short

Select

• SELECT <field_key>[,<field_key>,<tag_key>] FROM <measurement_name>[,<measurement_name>]

Where

• field value can be string/value

• tag value are all string

• timestamp

  • TODO: we can have a strict mode?
  • does it support now? now+1min etc. Yes it does, now() + 6m

• functions

Group by

• https://vimeo.com/200898048
• does not work with fields
• SELECT "water_level" FROM "h2o_feet" GROUP BY "location"