I'm usually a MySQL guy, so excuse and please correct me if I'm using the wrong expressions for something here.
I recently migrated to influxDB to store measurement data from a home automation system called "OpenHAB". A typical measurement/table would look like this: +---------------------+-------+ | time | value | +---------------------+-------+ | 2016-10-31 22:00:00 | 11.1 | | 2016-10-31 22:07:08 | 10.8 | | 2016-10-31 22:20:02 | 10.8 | | 2016-10-31 22:30:28 | 10.8 | | 2016-10-31 22:39:29 | 10.8 | | 2016-10-31 22:44:04 | 10.8 | | 2016-10-31 22:49:02 | 10.5 | | 2016-10-31 23:00:00 | 10.5 | | 2016-10-31 23:42:02 | 10 | | 2016-11-01 00:00:00 | 10 | | 2016-11-01 00:30:02 | 9.5 | | 2016-11-01 01:00:00 | 9.5 | | 2016-11-01 01:11:02 | 9.3 | | 2016-11-01 01:22:02 | 9.1 | The value type can be either float or string. What I want to do now is to delete every datapoint with the same value that occurred consecutively in a row, but always keep the first and the last one. So after the filtering process the ideal measurement would look like this: +---------------------+-------+ | time | value | +---------------------+-------+ | 2016-10-31 22:00:00 | 11.1 | | 2016-10-31 22:07:08 | 10.8 | <-- only here | 2016-10-31 22:44:04 | 10.8 | | 2016-10-31 22:49:02 | 10.5 | | 2016-10-31 23:00:00 | 10.5 | | 2016-10-31 23:42:02 | 10 | | 2016-11-01 00:00:00 | 10 | | 2016-11-01 00:30:02 | 9.5 | | 2016-11-01 01:00:00 | 9.5 | | 2016-11-01 01:11:02 | 9.3 | | 2016-11-01 01:22:02 | 9.1 | This has a simple background: - I don't want to delete any information since it can be valuable for future optimization processes (e.g. calculating thermal resistances) - Tough I still want to save storage space and optimize graphing processes by deleting redundant information - The first and the last point of a measurement indicates that the value stayed on the same level in between when looking at the data via Grafana etc. -- Remember to include the version number! --- You received this message because you are subscribed to the Google Groups "InfluxData" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/influxdb. To view this discussion on the web visit https://groups.google.com/d/msgid/influxdb/a10c37f3-3cfa-4c35-8230-4f6570392715%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
