From 38e6d911eaa2579f92c42dde31239f2736d2f893 Mon Sep 17 00:00:00 2001
From: Klaus Post <klauspost@gmail.com>
Date: Wed, 30 Oct 2019 09:16:55 +0100
Subject: [PATCH] S3 Select: Detect full object (#8456)

Check if select is `SELECT s.* from S3Object s` and forward it to All

Fixes #8371 and makes this case run significantly faster.
---
 pkg/s3select/select_test.go   | 10 ++++++++++
 pkg/s3select/sql/statement.go | 15 +++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/pkg/s3select/select_test.go b/pkg/s3select/select_test.go
index ba8b9214e..79ab00db7 100644
--- a/pkg/s3select/select_test.go
+++ b/pkg/s3select/select_test.go
@@ -165,6 +165,16 @@ func TestJSONQueries(t *testing.T) {
 			query:      `SELECT * from s3object s WHERE (7,8.5,9) = s.nested[1]`,
 			wantResult: `{"id":3,"title":"Second Record","desc":"another text","nested":[[2,3,4],[7,8.5,9]]}`,
 		},
+		{
+			name:       "indexed-list-match-equals-s-star",
+			query:      `SELECT s.* from s3object s WHERE (7,8.5,9) = s.nested[1]`,
+			wantResult: `{"id":3,"title":"Second Record","desc":"another text","nested":[[2,3,4],[7,8.5,9]]}`,
+		},
+		{
+			name:       "indexed-list-match-equals-s-index",
+			query:      `SELECT s.nested[1], s.nested[0] from s3object s WHERE (7,8.5,9) = s.nested[1]`,
+			wantResult: `{"_1":[7,8.5,9],"_2":[2,3,4]}`,
+		},
 		{
 			name:  "indexed-list-match-not-equals",
 			query: `SELECT * from s3object s WHERE (7,8.5,9) != s.nested[1]`,
diff --git a/pkg/s3select/sql/statement.go b/pkg/s3select/sql/statement.go
index 57814dfd8..fe42890a5 100644
--- a/pkg/s3select/sql/statement.go
+++ b/pkg/s3select/sql/statement.go
@@ -56,6 +56,21 @@ func ParseSelectStatement(s string) (stmt SelectStatement, err error) {
 		err = errQueryParseFailure(err)
 		return
 	}
+
+	// Check if select is "SELECT s.* from S3Object s"
+	if !selectAST.Expression.All &&
+		len(selectAST.Expression.Expressions) == 1 &&
+		len(selectAST.Expression.Expressions[0].Expression.And) == 1 &&
+		len(selectAST.Expression.Expressions[0].Expression.And[0].Condition) == 1 &&
+		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand != nil &&
+		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left != nil &&
+		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left.Left != nil &&
+		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left.Left.Primary != nil &&
+		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left.Left.Primary.JPathExpr != nil {
+		if selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left.Left.Primary.JPathExpr.String() == selectAST.From.As+".*" {
+			selectAST.Expression.All = true
+		}
+	}
 	stmt.selectAST = &selectAST
 
 	// Check the parsed limit value