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complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07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\u003eThe \u003ccode\u003eChildLink\u003c/code\u003e class provides metadata for parent-child relationships within a \u003ccode\u003ePlanNode\u003c/code\u003e in the \u003ccode\u003eGoogle.Cloud.Spanner.V1\u003c/code\u003e namespace.\u003c/p\u003e\n"],["\u003cp\u003eIt 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, for message handling, comparison, cloning, and buffered operations.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eChildLink\u003c/code\u003e class contains properties such as \u003ccode\u003eChildIndex\u003c/code\u003e (an integer for the node link), \u003ccode\u003eType\u003c/code\u003e (a string describing the link type), and \u003ccode\u003eVariable\u003c/code\u003e (a string for output variable names, if applicable).\u003c/p\u003e\n"],["\u003cp\u003eThere are two constructors available to create a \u003ccode\u003eChildLink\u003c/code\u003e object, either a default one, or one from another pre-existing \u003ccode\u003eChildLink\u003c/code\u003e object.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version available for \u003ccode\u003eChildLink\u003c/code\u003e is \u003ccode\u003e5.0.0-beta05\u003c/code\u003e but there are many previous version available going down to \u003ccode\u003e3.5.0\u003c/code\u003e.\u003c/p\u003e\n"]]],[],null,[]]
