tql eval supports SQL functions for start, end and step.

[killme2008]

What type of enhancement is this?

API improvement, User experience

What does the enhancement do?

Current tql eval parser only accepts timestamp literal as start andend parameter, for example:

TQL eval (1677057993, 1677058993, '1m') rate(prometheus_http_requests_total{job="prometheus"}[5m]);

Refer to https://docs.greptime.com/reference/sql/tql#eval

I think it's better to accept SQL functions such as now() for these parameters:

TQL eval ((now() - '5 minute'::interval)/1000, now()/1000, '1m') rate(prometheus_http_requests_total{job="prometheus"}[5m]);

Additionally, it would be beneficial if we could simplify the syntax by adding some syntactic sugar:

TQL eval(now - '5m', now, '1m') rate(prometheus_http_requests_total{job="prometheus"}

Implementation challenges

No response

[etolbakov]

@killme2008 happy to give it a go