It would be great if the query language would embrace more of the SQL92 standard (which includes substring function, for example).
https://en.wikipedia.org/wiki/SQL-92 On Monday, September 26, 2016 at 4:01:38 PM UTC-5, Sam Hatchett wrote: > > In trying to combine InfluxDB with Grafana's World Map plugin for > displaying time series data spatially, I've identified the need to > spatially subsample because I just have too many geographical points to > display all at once - too much lag time to return the result set. The > location's geohash provides a great way to do this (encoded as a tag value, > so I can group-by geohash to return some aggregate of potentially hundreds > of location's values), and then I can select the max, mean, min, etc., for > each spatial region, but the level of spatial aggregation has to be decided > prior to writing data to Influx. > > What I'm wondering about are the relative merits of workarounds, or of > finding some way to decide on the geohash length when the query is executed. > > So for instance, have multiple tags: (geo8, geo9, geo10 ...) for each > series so that I can decide on spatial subsampling when querying and choose > the right length: > select "value" from "temperature" where ... group by "geo8" > > But what I really want to do is store the full 12-character geohash for > each location and group by a substring of that geohash: > select "value" from "temperature" where ... group by substr("geohash",0,8) > > It's also useful to note that I can currently limit the locations that are > queried by using a regex: > select "value" from "temperature" where "geohash" =~ /^gbsuv7s/ > > ... but can't use a substring of the hash to do the group-by, which would > take me the rest of the way there. > > Any thoughts or comments would be most appreciated. I don't think that > there's a really straightforward solution right now, but does using a > substring (or other arbitrary transformation) of a tag value for grouping > make sense to anyone else? Seems like there could be many more uses of this > type of approach. > -- 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/7dd812f1-c1b9-4bf5-99c8-650caa0889a1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
