feat: honor appendOnly table config

README.md

@@ -159,7 +159,7 @@ of features outlined in the Delta [protocol][protocol] is also [tracked](#protoc
 
 | Writer Version | Requirement                                   |        Status        |
 | -------------- | --------------------------------------------- | :------------------: |
-| Version 2      | Append Only Tables                            |  [![open]][roadmap]  |
+| Version 2      | Append Only Tables                            |       ![done]  
 | Version 2      | Column Invariants                             |       ![done]        |
 | Version 3      | Enforce `delta.checkpoint.writeStatsAsJson`   | [![open]][writer-rs] |
 | Version 3      | Enforce `delta.checkpoint.writeStatsAsStruct` | [![open]][writer-rs] |

rust/src/operations/delete.rs

@@ -312,11 +312,14 @@ impl std::future::IntoFuture for DeleteBuilder {
 
 #[cfg(test)]
 mod tests {
-
     use crate::operations::DeltaOps;
     use crate::protocol::*;
     use crate::writer::test_utils::datafusion::get_data;
-    use crate::writer::test_utils::{get_arrow_schema, get_delta_schema};
+    use crate::writer::test_utils::{
+        get_arrow_schema, get_delta_schema, get_record_batch, setup_table_with_configuration,
+        write_batch,
+    };
+    use crate::DeltaConfigKey;
     use crate::DeltaTable;
     use arrow::array::Int32Array;
     use arrow::datatypes::{Field, Schema};
@@ -339,6 +342,19 @@ mod tests {
         table
     }
 
+    #[tokio::test]
+    async fn test_delete_when_delta_table_is_append_only() {
+        let table = setup_table_with_configuration(DeltaConfigKey::AppendOnly, Some("true")).await;
+        let batch = get_record_batch(None, false);
+        // append some data
+        let table = write_batch(table, batch).await;
+        // delete
+        let _err = DeltaOps(table)
+            .delete()
+            .await
+            .expect_err("Remove action is included when Delta table is append-only. Should error");
+    }
+
     #[tokio::test]
     async fn test_delete_default() {
         let schema = get_arrow_schema(&None);

rust/src/operations/merge.rs

@@ -532,7 +532,7 @@ impl MergeOperationConfig {
     }
 }
 
-#[derive(Default, Serialize)]
+#[derive(Default, Serialize, Debug)]
 /// Metrics for the Merge Operation
 pub struct MergeMetrics {
     /// Number of rows in the source data
@@ -1245,12 +1245,13 @@ impl std::future::IntoFuture for MergeBuilder {
 
 #[cfg(test)]
 mod tests {
-
     use crate::operations::DeltaOps;
     use crate::protocol::*;
     use crate::writer::test_utils::datafusion::get_data;
     use crate::writer::test_utils::get_arrow_schema;
     use crate::writer::test_utils::get_delta_schema;
+    use crate::writer::test_utils::setup_table_with_configuration;
+    use crate::DeltaConfigKey;
     use crate::DeltaTable;
     use arrow::datatypes::Schema as ArrowSchema;
     use arrow::record_batch::RecordBatch;
@@ -1277,6 +1278,21 @@ mod tests {
         table
     }
 
+    #[tokio::test]
+    async fn test_merge_when_delta_table_is_append_only() {
+        let schema = get_arrow_schema(&None);
+        let table = setup_table_with_configuration(DeltaConfigKey::AppendOnly, Some("true")).await;
+        // append some data
+        let table = write_data(table, &schema).await;
+        // merge
+        let _err = DeltaOps(table)
+            .merge(merge_source(schema), col("target.id").eq(col("source.id")))
+            .with_source_alias("source")
+            .with_target_alias("target")
+            .await
+            .expect_err("Remove action is included when Delta table is append-only. Should error");
+    }
+
     async fn write_data(table: DeltaTable, schema: &Arc<ArrowSchema>) -> DeltaTable {
         let batch = RecordBatch::try_new(
             Arc::clone(schema),
@@ -1300,14 +1316,7 @@ mod tests {
             .unwrap()
     }
 
-    async fn setup() -> (DeltaTable, DataFrame) {
-        let schema = get_arrow_schema(&None);
-        let table = setup_table(None).await;
-
-        let table = write_data(table, &schema).await;
-        assert_eq!(table.version(), 1);
-        assert_eq!(table.get_file_uris().count(), 1);
-
+    fn merge_source(schema: Arc<ArrowSchema>) -> DataFrame {
         let ctx = SessionContext::new();
         let batch = RecordBatch::try_new(
             Arc::clone(&schema),
@@ -1322,8 +1331,18 @@ mod tests {
             ],
         )
         .unwrap();
-        let source = ctx.read_batch(batch).unwrap();
-        (table, source)
+        ctx.read_batch(batch).unwrap()
+    }
+
+    async fn setup() -> (DeltaTable, DataFrame) {
+        let schema = get_arrow_schema(&None);
+        let table = setup_table(None).await;
+
+        let table = write_data(table, &schema).await;
+        assert_eq!(table.version(), 1);
+        assert_eq!(table.get_file_uris().count(), 1);
+
+        (table, merge_source(schema))
     }
 
     async fn assert_merge(table: DeltaTable, metrics: MergeMetrics) {

rust/src/operations/restore.rs

@@ -229,6 +229,7 @@ async fn execute(
             datetime: datetime_to_restore.map(|time| -> i64 { time.timestamp_millis() }),
         },
         &actions,
+        &snapshot,
         None,
     )
     .await?;

rust/src/operations/transaction/conflict_checker.rs

@@ -691,7 +691,7 @@ mod tests {
         actions: Vec<Action>,
         read_whole_table: bool,
     ) -> Result<(), CommitConflictError> {
-        let setup_actions = setup.unwrap_or_else(init_table_actions);
+        let setup_actions = setup.unwrap_or_else(|| init_table_actions(None));
         let state = DeltaTableState::from_actions(setup_actions, 0).unwrap();
         let transaction_info = TransactionInfo::new(&state, reads, &actions, read_whole_table);
         let summary = WinningCommitSummary {
@@ -717,7 +717,7 @@ mod tests {
         // the concurrent transaction deletes a file that the current transaction did NOT read
         let file_not_read = tu::create_add_action("file_not_read", true, get_stats(1, 10));
         let file_read = tu::create_add_action("file_read", true, get_stats(100, 10000));
-        let mut setup_actions = init_table_actions();
+        let mut setup_actions = init_table_actions(None);
         setup_actions.push(file_not_read);
         setup_actions.push(file_read);
         let result = execute_test(
@@ -733,7 +733,7 @@ mod tests {
         // concurrently add file, that the current transaction would not have read
         let file_added = tu::create_add_action("file_added", true, get_stats(1, 10));
         let file_read = tu::create_add_action("file_read", true, get_stats(100, 10000));
-        let mut setup_actions = init_table_actions();
+        let mut setup_actions = init_table_actions(None);
         setup_actions.push(file_read);
         let result = execute_test(
             Some(setup_actions),
@@ -797,7 +797,7 @@ mod tests {
         // delete / read
         // transaction reads a file that is removed by concurrent transaction
         let file_read = tu::create_add_action("file_read", true, get_stats(1, 10));
-        let mut setup_actions = init_table_actions();
+        let mut setup_actions = init_table_actions(None);
         setup_actions.push(file_read);
         let result = execute_test(
             Some(setup_actions),
@@ -842,7 +842,7 @@ mod tests {
         let file_part1 = tu::create_add_action("file_part1", true, get_stats(1, 10));
         let file_part2 = tu::create_add_action("file_part2", true, get_stats(11, 100));
         let file_part3 = tu::create_add_action("file_part3", true, get_stats(101, 1000));
-        let mut setup_actions = init_table_actions();
+        let mut setup_actions = init_table_actions(None);
         setup_actions.push(file_part1);
         let result = execute_test(
             Some(setup_actions),
@@ -858,7 +858,7 @@ mod tests {
         // `read_whole_table` should disallow any concurrent remove actions
         let file_part1 = tu::create_add_action("file_part1", true, get_stats(1, 10));
         let file_part2 = tu::create_add_action("file_part2", true, get_stats(11, 100));
-        let mut setup_actions = init_table_actions();
+        let mut setup_actions = init_table_actions(None);
         setup_actions.push(file_part1);
         let result = execute_test(
             Some(setup_actions),

rust/src/operations/transaction/mod.rs

@@ -48,6 +48,11 @@ pub enum TransactionError {
     /// Error returned when maximum number of commit trioals is exceeded
     #[error("Failed to commit transaction: {0}")]
     MaxCommitAttempts(i32),
+    /// The transaction includes Remove action with data change but Delta table is append-only
+    #[error(
+        "The transaction includes Remove action with data change but Delta table is append-only"
+    )]
+    DeltaTableAppendOnly,
 }
 
 impl From<TransactionError> for DeltaTableError {
@@ -68,9 +73,18 @@ impl From<TransactionError> for DeltaTableError {
 // Convert actions to their json representation
 fn log_entry_from_actions<'a>(
     actions: impl IntoIterator<Item = &'a Action>,
+    read_snapshot: &DeltaTableState,
 ) -> Result<String, TransactionError> {
+    let append_only = read_snapshot.table_config().append_only();
     let mut jsons = Vec::<String>::new();
     for action in actions {
+        if append_only {
+            if let Action::remove(remove) = action {
+                if remove.data_change {
+                    return Err(TransactionError::DeltaTableAppendOnly);
+                }
+            }
+        }
         let json = serde_json::to_string(action)
             .map_err(|e| TransactionError::SerializeLogJson { json_err: e })?;
         jsons.push(json);
@@ -81,6 +95,7 @@ fn log_entry_from_actions<'a>(
 pub(crate) fn get_commit_bytes(
     operation: &DeltaOperation,
     actions: &Vec<Action>,
+    read_snapshot: &DeltaTableState,
     app_metadata: Option<Map<String, Value>>,
 ) -> Result<bytes::Bytes, TransactionError> {
     if !actions.iter().any(|a| matches!(a, Action::commitInfo(..))) {
@@ -99,9 +114,13 @@ pub(crate) fn get_commit_bytes(
             actions
                 .iter()
                 .chain(std::iter::once(&Action::commitInfo(commit_info))),
+            read_snapshot,
         )?))
     } else {
-        Ok(bytes::Bytes::from(log_entry_from_actions(actions)?))
+        Ok(bytes::Bytes::from(log_entry_from_actions(
+            actions,
+            read_snapshot,
+        )?))
     }
 }
 
@@ -112,10 +131,11 @@ pub(crate) async fn prepare_commit<'a>(
     storage: &dyn ObjectStore,
     operation: &DeltaOperation,
     actions: &Vec<Action>,
+    read_snapshot: &DeltaTableState,
     app_metadata: Option<Map<String, Value>>,
 ) -> Result<Path, TransactionError> {
     // Serialize all actions that are part of this log entry.
-    let log_entry = get_commit_bytes(operation, actions, app_metadata)?;
+    let log_entry = get_commit_bytes(operation, actions, read_snapshot, app_metadata)?;
 
     // Write delta log entry as temporary file to storage. For the actual commit,
     // the temporary file is moved (atomic rename) to the delta log folder within `commit` function.
@@ -177,7 +197,8 @@ pub async fn commit_with_retries(
     app_metadata: Option<Map<String, Value>>,
     max_retries: usize,
 ) -> DeltaResult<i64> {
-    let tmp_commit = prepare_commit(storage, &operation, actions, app_metadata).await?;
+    let tmp_commit =
+        prepare_commit(storage, &operation, actions, read_snapshot, app_metadata).await?;
 
     let mut attempt_number = 1;
 
@@ -218,9 +239,11 @@ pub async fn commit_with_retries(
 
 #[cfg(all(test, feature = "parquet"))]
 mod tests {
-    use self::test_utils::init_table_actions;
+    use self::test_utils::{create_remove_action, init_table_actions};
     use super::*;
+    use crate::DeltaConfigKey;
     use object_store::memory::InMemory;
+    use std::collections::HashMap;
 
     #[test]
     fn test_commit_uri_from_version() {
@@ -232,13 +255,36 @@ mod tests {
 
     #[test]
     fn test_log_entry_from_actions() {
-        let actions = init_table_actions();
-        let entry = log_entry_from_actions(&actions).unwrap();
+        let actions = init_table_actions(None);
+        let state = DeltaTableState::from_actions(actions.clone(), 0).unwrap();
+        let entry = log_entry_from_actions(&actions, &state).unwrap();
         let lines: Vec<_> = entry.lines().collect();
         // writes every action to a line
         assert_eq!(actions.len(), lines.len())
     }
 
+    fn remove_action_exists_when_delta_table_is_append_only(
+        data_change: bool,
+    ) -> Result<String, TransactionError> {
+        let remove = create_remove_action("test_append_only", data_change);
+        let mut actions = init_table_actions(Some(HashMap::from([(
+            DeltaConfigKey::AppendOnly.as_ref().to_string(),
+            Some("true".to_string()),
+        )])));
+        actions.push(remove);
+        let state =
+            DeltaTableState::from_actions(actions.clone(), 0).expect("Failed to get table state");
+        log_entry_from_actions(&actions, &state)
+    }
+
+    #[test]
+    fn test_remove_action_exists_when_delta_table_is_append_only() {
+        let _err = remove_action_exists_when_delta_table_is_append_only(true)
+            .expect_err("Remove action is included when Delta table is append-only. Should error");
+        let _actions = remove_action_exists_when_delta_table_is_append_only(false)
+            .expect("Data is not changed by the Remove action. Should succeed");
+    }
+
     #[tokio::test]
     async fn test_try_commit_transaction() {
         let store = InMemory::new();

rust/src/operations/transaction/state.rs

@@ -334,7 +334,7 @@ mod tests {
 
     #[test]
     fn test_parse_predicate_expression() {
-        let snapshot = DeltaTableState::from_actions(init_table_actions(), 0).unwrap();
+        let snapshot = DeltaTableState::from_actions(init_table_actions(None), 0).unwrap();
         let session = SessionContext::new();
         let state = session.state();
 
@@ -361,7 +361,7 @@ mod tests {
 
     #[test]
     fn test_files_matching_predicate() {
-        let mut actions = init_table_actions();
+        let mut actions = init_table_actions(None);
         actions.push(create_add_action("excluded", true, Some("{\"numRecords\":10,\"minValues\":{\"value\":1},\"maxValues\":{\"value\":10},\"nullCount\":{\"value\":0}}".into())));
         actions.push(create_add_action("included-1", true, Some("{\"numRecords\":10,\"minValues\":{\"value\":1},\"maxValues\":{\"value\":100},\"nullCount\":{\"value\":0}}".into())));
         actions.push(create_add_action("included-2", true, Some("{\"numRecords\":10,\"minValues\":{\"value\":-10},\"maxValues\":{\"value\":3},\"nullCount\":{\"value\":0}}".into())));

rust/src/operations/transaction/test_utils.rs

@@ -72,7 +72,7 @@ pub fn create_metadata_action(
     Action::metaData(MetaData::try_from(metadata).unwrap())
 }
 
-pub fn init_table_actions() -> Vec<Action> {
+pub fn init_table_actions(configuration: Option<HashMap<String, Option<String>>>) -> Vec<Action> {
     let raw = r#"
         {
             "timestamp": 1670892998177,
@@ -96,7 +96,7 @@ pub fn init_table_actions() -> Vec<Action> {
     vec![
         Action::commitInfo(commit_info),
         create_protocol_action(None, None),
-        create_metadata_action(None, None),
+        create_metadata_action(None, configuration),
     ]
 }
 
@@ -127,7 +127,7 @@ pub async fn create_initialized_table(
             HashMap::new(),
         ),
     ]);
-    let state = DeltaTableState::from_actions(init_table_actions(), 0).unwrap();
+    let state = DeltaTableState::from_actions(init_table_actions(None), 0).unwrap();
     let operation = DeltaOperation::Create {
         mode: SaveMode::ErrorIfExists,
         location: "location".into(),
@@ -144,8 +144,8 @@ pub async fn create_initialized_table(
             configuration.unwrap_or_default(),
         ),
     };
-    let actions = init_table_actions();
-    let prepared_commit = prepare_commit(storage.as_ref(), &operation, &actions, None)
+    let actions = init_table_actions(None);
+    let prepared_commit = prepare_commit(storage.as_ref(), &operation, &actions, &state, None)
         .await
         .unwrap();
     try_commit_transaction(storage.as_ref(), &prepared_commit, 0)