Kibana Cavas empty datatable

Hi, I am facing strange issue.
I have created canvas report like below. Anyway, I am getting random icons with exclamation marks, but when I reload data with Alt+R, they randomly disapear and reapear on different metric., after several reloads everything is OK but nex one again causes this issue.
Am I missing something??

Hi @Zdeno_Liska — Could you share specifically how you created those numbers on your workpad (which canvas element did you use, or is this a custom expression)?

Hi, thanks for reply:
here is original code causing issue:

kibana
| selectFilter group="by-device" group="by-date1" ungrouped=true
| essql 
  query="SELECT AVG(\"P1-C01-Temp\") as avg, Round(STDDEV_SAMP(\"P1-C01-Temp\"),2) as std_samp,Round(STDDEV_POP(\"P1-C01-Temp\"),2) as std_pop, prodTimeSpan ts FROM \"metrics-factory*\" WHERE position='RC1' GROUP BY prodTimeSpan order by avg DESC LIMIT 1"
| math "ts"
| metric "" 
  metricFont={font align="center" color="#1785b0" family="'Open Sans', Helvetica, Arial, sans-serif" italic=false size=14 underline=false weight="bold"} 
  labelFont={font size=14 family="'Open Sans', Helvetica, Arial, sans-serif" color="#000000" align="center"} metricFormat="0,0"
| render

and here is update that seems as a solution for me that I found after I posted this question:
kibana

kibana
| selectFilter group="by-device" group="by-date1" ungrouped=true
| essql 
  query="SELECT AVG(\"P1-C01-Temp\") as avg, Round(STDDEV_SAMP(\"P1-C01-Temp\"),2) as std_samp,Round(STDDEV_POP(\"P1-C01-Temp\"),2) as std_pop, prodTimeSpan ts FROM \"metrics-factory*\" WHERE position='RC1' GROUP BY prodTimeSpan order by avg DESC LIMIT 1"
| if {rowCount | eq 0} then=0 else={math "ts"}
| metric "" 
  metricFont={font align="center" color="#1785b0" family="'Open Sans', Helvetica, Arial, sans-serif" italic=false size=14 underline=false weight="bold"} 
  labelFont={font size=14 family="'Open Sans', Helvetica, Arial, sans-serif" color="#000000" align="center"} metricFormat="0,0"
| render

anyway, is there a possibility to perform some query only once if it is commonfor multiple elements and then somehow refer to result of this query? Concept of variables seems to be out of options as there is no defined order of expressions evaluations. I am just curious

is there a possibility to perform some query only once if it is commonfor multiple elements and then somehow refer to result of this query?

We don't have the concept of elements referencing each other in Canvas. It kind of reminds me of this issue, but I don't know of any plans to add this as something you could use when building a Canvas workpad.

cc: @devon.thomson

Hi @Zdeno_Liska, I can confirm what @Andrew_Tate said, there is currently no way to store and re-use partial query results in a Canvas workpad.