From c619a17d9d0bf8c8da6585799b2a706a1776176d Mon Sep 17 00:00:00 2001
From: evenyag <realevenyag@gmail.com>
Date: Tue, 15 Aug 2023 21:26:37 +0800
Subject: [PATCH] feat: sort fields by column id

---
 src/mito2/src/read.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/mito2/src/read.rs b/src/mito2/src/read.rs
index ac0112f56b59..94747c1eec01 100644
--- a/src/mito2/src/read.rs
+++ b/src/mito2/src/read.rs
@@ -47,6 +47,9 @@ pub struct Batch {
     /// UInt8 type, not null.
     op_types: Arc<UInt8Vector>,
     /// Fields organized in columnar format.
+    ///
+    /// Fields are ordered by their column id so the batch after projection
+    /// is always consistent.
     fields: Vec<BatchColumn>,
 }
 
@@ -261,6 +264,8 @@ impl BatchBuilder {
                 }
             );
         }
+        // Sort fields by column id.
+        self.fields.sort_unstable_by_key(|field| field.column_id);
 
         Ok(Batch {
             primary_key: self.primary_key,