From b463fd6194a68b641160f872c387584ab89b2fe8 Mon Sep 17 00:00:00 2001
From: ion-elgreco <15728914+ion-elgreco@users.noreply.github.com>
Date: Tue, 30 Jul 2024 17:48:13 +0300
Subject: [PATCH] check if column mapping is enabled

---
 crates/core/src/operations/drop_column.rs | 36 +++++++++++++++++++++--
 1 file changed, 33 insertions(+), 3 deletions(-)

diff --git a/crates/core/src/operations/drop_column.rs b/crates/core/src/operations/drop_column.rs
index 6f0b22ca6e..7463427ee8 100644
--- a/crates/core/src/operations/drop_column.rs
+++ b/crates/core/src/operations/drop_column.rs
@@ -1,5 +1,6 @@
 //! Drop a column from the table
 
+use delta_kernel::column_mapping::ColumnMappingMode;
 use delta_kernel::schema::DataType;
 use delta_kernel::schema::StructType;
 use futures::future::BoxFuture;
@@ -9,9 +10,10 @@ use itertools::Itertools;
 use sqlparser::dialect::GenericDialect;
 use sqlparser::parser::Parser;
 
-use super::transaction::{CommitBuilder, CommitProperties};
+use super::transaction::TransactionError;
+use super::transaction::{CommitBuilder, CommitProperties, PROTOCOL};
 
-use crate::kernel::StructField;
+use crate::kernel::{StructField, WriterFeatures};
 use crate::logstore::LogStoreRef;
 use crate::protocol::DeltaOperation;
 use crate::table::state::DeltaTableState;
@@ -72,6 +74,32 @@ impl std::future::IntoFuture for DropColumnBuilder {
         let this = self;
 
         Box::pin(async move {
+            let protocol = this.snapshot.protocol();
+
+            // Check if column mapping is enabled
+            if vec![5, 6].contains(&protocol.min_writer_version)
+                && this.snapshot.table_config().column_mapping_mode() == ColumnMappingMode::None
+            {
+                return Err(DeltaTableError::Generic(
+                    "Column mapping mode shouldn't be None".to_string(),
+                ));
+            } else if protocol.min_writer_version == 7
+                && !protocol
+                    .writer_features
+                    .as_ref()
+                    .map(|v| v.contains(&crate::kernel::WriterFeatures::ColumnMapping))
+                    .unwrap_or_default()
+            {
+                return Err(DeltaTableError::Transaction {
+                    source: TransactionError::WriterFeaturesRequired(WriterFeatures::ColumnMapping),
+                });
+            } else if protocol.min_writer_version < 5 {
+                return Err(DeltaTableError::Generic(format!(
+                    "Min writer >= 5, current version is ({})",
+                    protocol.min_writer_version
+                )));
+            };
+
             let dialect = GenericDialect {};
             let mut metadata = this.snapshot.metadata().clone();
             let fields = match this.fields {
@@ -138,7 +166,9 @@ impl std::future::IntoFuture for DropColumnBuilder {
                     .collect_vec(),
             );
 
-            if !not_found.is_empty() && this.raise_if_not_exists {
+            if (!not_found.is_empty() || table_schema.ne(&new_table_schema))
+                && this.raise_if_not_exists
+            {
                 return Err(DeltaTableError::Generic(format!(
                     "Column(s) with name: {:#?} doesn't exist",
                     &not_found