Possible precision loss w/ Crate 4.4.+ geoqueries

[c0c0n3]

This is just a reminder to check out if geo queries are still working with enough accuracy in Crate 4.4+. See this comment to PR #481

• https://github.com/orchestracities/ngsi-timeseries-api/pull/481#discussion_r635246517

Geo queries use the location centroid column, not the location column, but the problem should be the same, i.e. we might have to use _doc[loc_centroid] instead of just the plain column name when building Crate geo queries.

[amotl]

Hi @c0c0n3,

I just want to point out https://github.com/orchestracities/ngsi-timeseries-api/issues/430#issuecomment-777781639 ff. in this context.

With kind regards, Andreas.

[c0c0n3]

Hi @amotl, thanks for this, I'd just plain forgot about that! Thank goodness you're always around when we need you :-)

[daminichopra]

Hi @chicco785 @c0c0n3 , I have been trying to test for comment but not able to notify data to quantum leap using geo queries and not able to find proper usage of geo queries API . Please let me know if I am missing something. Also, I would like to contribute in this issue.

[c0c0n3]

Hi @daminichopra thanks alot for looking into this! Geo-queries are documented in the API spec, then we've got Python docs too, e.g. https://github.com/orchestracities/ngsi-timeseries-api/blob/master/src/geocoding/slf/init.py and you can also look at the original pr #111...

[daminichopra]

@c0c0n3 , I will look into it. Thank you

[daminichopra]

Hi @c0c0n3 , Below are some observation points after tested geo queries with Crate 4.4+

1. Regarding this comment we have to use _doc[loc_centroid] instead of just the plain column name
   select latitude(_doc['location_centroid']), longitude(_doc['location_centroid']) from ettest;

2. Also, SELECT _doc['location'] instead of SELECT location

Note: Tested above queries with both crate 4.4.2 and 4.4.3

[daminichopra]

Soft Reminder!! Please let me know if any further investigation is needed to be done. Thank you

[c0c0n3]

Hi @daminichopra!

Sorry for the slow reply, I was away on holiday and busy w/ other projects. Also I'll be away for another two weeks, but I'll try to catch up w/ QL issues in September.

Re: your investigation, that's great thank you so much. I don't think we need to dig deeper, since it looks like you've already got to the bottom of it :-)

[github-actions[bot]]

Stale issue message

[daminichopra]

Hi @c0c0n3 @chicco785 , Please close this issue if no further investigation required. Thank you

[c0c0n3]

@daminichopra like I said you've done a thorough investigation and clarified what the situation actually is. Thanks alot for that :-) But shouldn't we keep this issue as a reminder to possibly update the Crate geo query generator (translators.crate_geo_query) as you suggested? That is, use _doc['location_centroid'] instead of the plain column name of location_centroid?