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This implements `INLINESTATS`. Most of the heavy lifting is done by `LOOKUP`, with this change mostly adding a new abstraction to logical plans, and interface I'm calling `Phased`. Implementing this interface allows a logical plan node to cut the query into phases. `INLINESTATS` implements it by asking for a "first phase" that's the same query, up to `INLINESTATS`, but with `INLINESTATS` replaced with `STATS`. The next phase replaces the `INLINESTATS` with a `LOOKUP` on the results of the first phase. So, this query: ``` FROM foo | EVAL bar = a * b | INLINESTATS m = MAX(bar) BY b | WHERE m = bar | LIMIT 1 ``` gets split into ``` FROM foo | EVAL bar = a * b | STATS m = MAX(bar) BY b ``` followed by ``` FROM foo | EVAL bar = a * b | LOOKUP (results of m = MAX(bar) BY b) ON b | WHERE m = bar | LIMIT 1 ```
64 lines
1.6 KiB
Text
64 lines
1.6 KiB
Text
[discrete]
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[[esql-lookup]]
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=== `LOOKUP`
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experimental::["LOOKUP is highly experimental and only available in SNAPSHOT versions."]
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`LOOKUP` matches values from the input against a `table` provided in the request,
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adding the other fields from the `table` to the output.
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**Syntax**
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[source,esql]
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----
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LOOKUP table ON match_field1[, match_field2, ...]
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----
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*Parameters*
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`table`::
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The name of the `table` provided in the request to match.
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If the table's column names conflict with existing columns, the existing columns will be dropped.
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`match_field`::
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The fields in the input to match against the table.
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*Examples*
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// tag::examples[]
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[source,console,id=esql-lookup-example]
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----
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POST /_query?format=txt
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{
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"query": """
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FROM library
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| SORT page_count DESC
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| KEEP name, author
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| LOOKUP era ON author
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| LIMIT 5
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""",
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"tables": {
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"era": {
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"author": {"keyword": ["Frank Herbert", "Peter F. Hamilton", "Vernor Vinge", "Alastair Reynolds", "James S.A. Corey"]},
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"era": {"keyword": [ "The New Wave", "Diamond", "Diamond", "Diamond", "Hadron"]}
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}
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}
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}
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----
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// TEST[setup:library]
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Which returns:
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[source,text]
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----
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name | author | era
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--------------------+-----------------+---------------
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Pandora's Star |Peter F. Hamilton|Diamond
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A Fire Upon the Deep|Vernor Vinge |Diamond
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Dune |Frank Herbert |The New Wave
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Revelation Space |Alastair Reynolds|Diamond
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Leviathan Wakes |James S.A. Corey |Hadron
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----
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// TESTRESPONSE[s/\|/\\|/ s/\+/\\+/]
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// TESTRESPONSE[non_json]
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// end::examples[]
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