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Merge pull request #818 from influxdata/js-influxql-normalize-time-spec 

feat(query/influxql): update the spec for time normalization in selectors
pull/10616/head
Jonathan A. Sternberg 2018-09-11 13:26:37 -05:00 committed by GitHub
parent 402cf4d3f6 131767572e
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11
query/influxql/README.md
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@ -14,7 +14,8 @@ The InfluxQL Transpiler exists to rewrite an InfluxQL query into its equivalent
4. [Evaluate the condition](#evaluate-condition)
5. [Perform the grouping](#perform-grouping)
6. [Evaluate the function](#evaluate-function)
7. [Combine windows](#combine-windows)
7. [Normalize the time column](#normalize-time)
8. [Combine windows](#combine-windows)
5. [Join the groups](#join-groups)
6. [Map and eval columns](#map-and-eval)
7. [Encoding the results](#encoding)
@ -111,6 +112,14 @@ For an aggregate, the following is used instead:
If the aggregate is combined with conditions, the column name of `_value` is replaced with whatever the generated column name is.
### <a name="normalize-time"></a> Normalize the time column
If a function was evaluated and the query type is an aggregate type, then all of the selector functions need to have their time normalized.
... |> max() |> drop(columns: ["_time"]) |> duplicate(column: "_start", as: "_time")
This **only gets applied to selectors when being run as an aggregate**. This step is skipped if the query is running as a selector and it does not apply when processing raw data.
### <a name="combine-windows"></a> Combine windows
If there a window operation was added, we then combine each of the function results from the windows back into a single table.