From 065892fb1fad4f249befa1fe3327b4107d0fd7a6 Mon Sep 17 00:00:00 2001
From: Lei Xu <lei@eto.ai>
Date: Sun, 4 Dec 2022 22:42:14 -0800
Subject: [PATCH 1/2] read special version of dataset

---
 cpp/src/lance/arrow/dataset.cc                 | 11 ++++++++++-
 .../duckdb/src/lance/duckdb/lance_reader.cc    | 18 ++++++++++++++++--
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/cpp/src/lance/arrow/dataset.cc b/cpp/src/lance/arrow/dataset.cc
index 00e89791cb..aa6a13efb2 100644
--- a/cpp/src/lance/arrow/dataset.cc
+++ b/cpp/src/lance/arrow/dataset.cc
@@ -313,7 +313,16 @@ ::arrow::Result<std::shared_ptr<LanceDataset>> LanceDataset::Make(
   if (finfo.type() == ::arrow::fs::FileType::NotFound) {
     return ::arrow::Status::IOError("Manifest not found: ", manifest_path);
   }
-  ARROW_ASSIGN_OR_RAISE(auto manifest, OpenManifest(fs, manifest_path));
+  auto result = OpenManifest(fs, manifest_path);
+
+  if (result.status().IsIOError() && result.status().message().starts_with("Path does not exist")) {
+    if (!version) {
+      return ::arrow::Status::IOError("Can not find the latest version of the dataset");
+    }
+    return ::arrow::Status::IOError("Version ", version.value(), " does not exist");
+  }
+
+  ARROW_ASSIGN_OR_RAISE(auto manifest, result);
   auto impl = std::make_unique<LanceDataset::Impl>(fs, base_uri, manifest);
   return std::shared_ptr<LanceDataset>(new LanceDataset(std::move(impl)));
 }
diff --git a/integration/duckdb/src/lance/duckdb/lance_reader.cc b/integration/duckdb/src/lance/duckdb/lance_reader.cc
index 9bc93f7a14..ca1a9a8ea4 100644
--- a/integration/duckdb/src/lance/duckdb/lance_reader.cc
+++ b/integration/duckdb/src/lance/duckdb/lance_reader.cc
@@ -28,6 +28,7 @@
 #include <duckdb/parser/expression/constant_expression.hpp>
 #include <duckdb/parser/expression/function_expression.hpp>
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -59,9 +60,13 @@ std::unique_ptr<::duckdb::FunctionData> LanceScanBind(
     std::vector<::duckdb::LogicalType> &return_types,
     std::vector<std::string> &names) {
   auto dataset_uri = input.inputs[0].GetValue<std::string>();
+  std::optional<uint64_t> version = std::nullopt;
+  if (input.inputs.size() > 1) {
+    version = input.inputs[1].GetValue<int>();
+  }
   std::string path;
   auto fs = GetResult(::arrow::fs::FileSystemFromUriOrPath(dataset_uri, &path));
-  auto dataset = GetResult(lance::arrow::LanceDataset::Make(std::move(fs), path));
+  auto dataset = GetResult(lance::arrow::LanceDataset::Make(std::move(fs), path, version));
   auto schema = dataset->schema();
   auto bind_data = std::make_unique<ScanBindData>();
   bind_data->dataset = std::move(dataset);
@@ -282,8 +287,17 @@ ::duckdb::TableFunctionSet GetLanceReaderFunction() {
   table_function.projection_pushdown = true;
   table_function.filter_pushdown = true;
   table_function.filter_prune = true;
-
   func_set.AddFunction(table_function);
+
+  ::duckdb::TableFunction scan_with_version(
+      {::duckdb::LogicalType::VARCHAR, ::duckdb::LogicalType::INTEGER},
+      LanceScan,
+      LanceScanBind,
+      InitGlobal);
+  scan_with_version.projection_pushdown = true;
+  scan_with_version.filter_pushdown = true;
+  scan_with_version.filter_prune = true;
+  func_set.AddFunction(scan_with_version);
   return func_set;
 }
 

From 1ba865e039bc33bddbbc7618e4617a8d236c2d7b Mon Sep 17 00:00:00 2001
From: Lei Xu <lei@eto.ai>
Date: Sun, 4 Dec 2022 22:52:56 -0800
Subject: [PATCH 2/2] reduce code

---
 .../duckdb/src/lance/duckdb/lance_reader.cc   | 26 +++++++------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/integration/duckdb/src/lance/duckdb/lance_reader.cc b/integration/duckdb/src/lance/duckdb/lance_reader.cc
index ca1a9a8ea4..3b4109914c 100644
--- a/integration/duckdb/src/lance/duckdb/lance_reader.cc
+++ b/integration/duckdb/src/lance/duckdb/lance_reader.cc
@@ -282,22 +282,16 @@ void LanceScan(::duckdb::ClientContext &context,
 ::duckdb::TableFunctionSet GetLanceReaderFunction() {
   ::duckdb::TableFunctionSet func_set("lance_scan");
 
-  ::duckdb::TableFunction table_function(
-      {::duckdb::LogicalType::VARCHAR}, LanceScan, LanceScanBind, InitGlobal);
-  table_function.projection_pushdown = true;
-  table_function.filter_pushdown = true;
-  table_function.filter_prune = true;
-  func_set.AddFunction(table_function);
-
-  ::duckdb::TableFunction scan_with_version(
-      {::duckdb::LogicalType::VARCHAR, ::duckdb::LogicalType::INTEGER},
-      LanceScan,
-      LanceScanBind,
-      InitGlobal);
-  scan_with_version.projection_pushdown = true;
-  scan_with_version.filter_pushdown = true;
-  scan_with_version.filter_prune = true;
-  func_set.AddFunction(scan_with_version);
+  for (auto &arguments : std::vector<std::vector<::duckdb::LogicalType>>(
+           {{::duckdb::LogicalType::VARCHAR},
+            {::duckdb::LogicalType::VARCHAR, ::duckdb::LogicalType::INTEGER}})) {
+    ::duckdb::TableFunction table_function(
+        arguments, LanceScan, LanceScanBind, InitGlobal);
+    table_function.projection_pushdown = true;
+    table_function.filter_pushdown = true;
+    table_function.filter_prune = true;
+    func_set.AddFunction(table_function);
+  }
   return func_set;
 }