The type of the link. For example, in Hash Joins this could be used to
distinguish between the build child and the probe child, or in the case
of the child being an output variable, to represent the tag associated
with the output variable.
Only present if the child node is [SCALAR][google.spanner.v1.PlanNode.Kind.SCALAR] and corresponds
to an output variable of the parent node. The field carries the name of
the output variable.
For example, a TableScan operator that reads rows from a table will
have child links to the SCALAR nodes representing the output variables
created for each column that is read by the operator. The corresponding
variable fields will be set to the variable names assigned to the
columns.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07 UTC."],[[["\u003cp\u003eThis document outlines the \u003ccode\u003eChildLink\u003c/code\u003e class, which is part of the \u003ccode\u003eGoogle.Cloud.Spanner.V1\u003c/code\u003e namespace, detailing its role in representing parent-child relationships within a \u003ccode\u003ePlanNode\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eChildLink\u003c/code\u003e class implements several interfaces, including \u003ccode\u003eIMessage\u003c/code\u003e, \u003ccode\u003eIEquatable\u003c/code\u003e, \u003ccode\u003eIDeepCloneable\u003c/code\u003e, and \u003ccode\u003eIBufferMessage\u003c/code\u003e, ensuring its compatibility with various protobuf operations.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eChildLink\u003c/code\u003e class offers properties like \u003ccode\u003eChildIndex\u003c/code\u003e, \u003ccode\u003eType\u003c/code\u003e, and \u003ccode\u003eVariable\u003c/code\u003e, which are used to describe the nature and specifics of the link between a parent and a child node.\u003c/p\u003e\n"],["\u003cp\u003eThe document provides version history for the \u003ccode\u003eChildLink\u003c/code\u003e class, with version 5.0.0-beta05 being the latest and also links back to older versions all the way back to 3.5.0.\u003c/p\u003e\n"],["\u003cp\u003eTwo constructors, \u003ccode\u003eChildLink()\u003c/code\u003e and \u003ccode\u003eChildLink(PlanNode.Types.ChildLink other)\u003c/code\u003e, allow for creating new instances, either empty or as copies of existing \u003ccode\u003eChildLink\u003c/code\u003e objects.\u003c/p\u003e\n"]]],[],null,[]]
