From 3e98846a991ea53cf7dc98b7d7957bfd4fc494a6 Mon Sep 17 00:00:00 2001
From: Adam Perlin <adamp@nanosoft.com>
Date: Wed, 1 Aug 2018 09:09:45 -0700
Subject: [PATCH] Specify how group key is handled in rename/drop spec (#524)
* Specify how group key is handled in rename/drop spec
---
query/docs/SPEC.md | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/query/docs/SPEC.md b/query/docs/SPEC.md
index c4a7515205..ca8177161f 100644
--- a/query/docs/SPEC.md
+++ b/query/docs/SPEC.md
@@ -1086,9 +1086,10 @@ Range has the following properties:
#### Rename
-Rename will rename specified columns in a data table.
+Rename will rename specified columns in a table.
There are two variants: one which takes a map of old column names to new column names,
- and one which takes a mapping function.
+and one which takes a mapping function.
+If a column is renamed and is part of the group key, the column name in the group key will be updated.
Rename has the following properties:
* `columns` object
@@ -1105,8 +1106,9 @@ Rename all columns with `fn` parameter: `rename(fn: (col) => "{col}_new")`
#### Drop
-Drop will exclude specified columns from a returned data table. Columns to exclude can be specified either through a
+Drop will exclude specified columns from a table. Columns to exclude can be specified either through a
list, or a predicate function.
+When a dropped column is part of the group key it will also be dropped from the key.
Drop has the following properties:
* `columns` array of strings
@@ -1123,8 +1125,9 @@ Drop all columns matching a predicate: `drop(fn: (col) => col =~ /usage*/)`
#### Keep
-Keep can be thought of as the inverse of drop. It will return a table containing only columns that are specified,
-ignoring all others.
+Keep is the inverse of drop. It will return a table containing only columns that are specified,
+ignoring all others.
+Only columns in the group key that are also specified in `keep` will be kept in the resulting group key.
Keep has the following properties:
* `columns` array of strings