Fix XXX comment about recursion in get_restriction_variable()

Nikita Glukhov · Nikita Glukhov · commit ad41d088ca71 · 2022-03-11T00:52:04.000+03:00
diff --git a/src/backend/utils/adt/jsonb_selfuncs.c b/src/backend/utils/adt/jsonb_selfuncs.c
@@ -996,8 +996,9 @@ jsonbStatsVarOpConst(Oid opid, VariableStatData *resdata,
  *
  * This only supports OpExpr expressions, with (Var op Const) shape.
  *
- * XXX It might be useful to allow recursion, i.e. get_restriction_variable
- * might derive statistics too. I don't think it does that now, right?
+ * Var really can be a chain of OpExprs with derived statistics
+ * (jsonb_column -> 'key1' -> key2'), because get_restriction_variable()
+ * already handles this case.
  */
 Datum
 jsonb_stats(PG_FUNCTION_ARGS)

Original file line number	Diff line number	Diff line change
`@@ -996,8 +996,9 @@ jsonbStatsVarOpConst(Oid opid, VariableStatData *resdata,`
`996`	`996`	`*`
`997`	`997`	`* This only supports OpExpr expressions, with (Var op Const) shape.`
`998`	`998`	`*`
`999`		`- * XXX It might be useful to allow recursion, i.e. get_restriction_variable`
`1000`		`- * might derive statistics too. I don't think it does that now, right?`
	`999`	`+ * Var really can be a chain of OpExprs with derived statistics`
	`1000`	`+ * (jsonb_column -> 'key1' -> key2'), because get_restriction_variable()`
	`1001`	`+ * already handles this case.`
`1001`	`1002`	`*/`
`1002`	`1003`	`Datum`
`1003`	`1004`	`jsonb_stats(PG_FUNCTION_ARGS)`