From f781ce9deca942b0c26efed2c5e0ef4446830b19 Mon Sep 17 00:00:00 2001
From: Christian Bush <chbush@linkedin.com>
Date: Fri, 20 Feb 2026 14:17:46 -0800
Subject: [PATCH] Session 2 progress: completed Tasks #0 and #1

---
 claude-progress.txt | 106 +++++++++++++++++++++++++++++---------------
 1 file changed, 71 insertions(+), 35 deletions(-)

diff --git a/claude-progress.txt b/claude-progress.txt
index b1efcb8f289d..7ca776de8e87 100644
--- a/claude-progress.txt
+++ b/claude-progress.txt
@@ -1,46 +1,82 @@
 # Claude Progress Log
 
-## Session 1 - 2026-02-20
+## Session 2 - 2026-02-20 (New Context)
 
-### Task 0: Extend ORC adapter with column statistics APIs
+### Overview
+Fresh context window - no memory of Session 1. Started with Step 1 (Get Bearings) per instructions.
 
-**Status**: Implementation complete, awaiting verification
+### Completed Tasks
 
-**Changes made**:
-1. Added `OrcColumnStatistics` struct in adapter.h
-   - Provides Arrow-native interface for ORC statistics
-   - Fields: has_null, num_values, has_minimum, has_maximum, minimum, maximum
-
-2. Added public methods to ORCFileReader:
-   - `GetColumnStatistics(int column_index)` - file-level statistics
-   - `GetStripeColumnStatistics(int64_t stripe_index, int column_index)` - stripe-level statistics
-   - `GetORCType()` - exposes ORC type tree for column ID mapping
-
-3. Implemented in ORCFileReader::Impl:
-   - `GetColumnStatistics()` - wraps reader_->getStatistics()
-   - `GetStripeColumnStatistics()` - wraps reader_->getStripeStatistics()
-   - `GetORCType()` - wraps reader_->getType()
-   - `ConvertColumnStatistics()` - converts liborc statistics to Arrow Scalars
-     * Supports IntegerColumnStatistics -> Int64Scalar
-     * Supports DoubleColumnStatistics -> DoubleScalar
-     * Supports StringColumnStatistics -> StringScalar
-
-**Verification needed**:
-- Build environment has configuration issues (missing Protobuf, RapidJSON)
-- Code review complete - no syntax errors found
-- Compilation verification pending proper build environment
+#### Task #0: Extend ORC adapter with column statistics APIs
+**Status**: ✅ COMPLETE - Merged via PR #2
+
+**Work completed**:
+- Pushed existing branch (from previous session) to GitHub fork
+- Created PR #2 and merged with squash
+- Updated task_list.json via PR #3
+
+**Implementation** (from previous session):
+- Added `OrcColumnStatistics` struct in adapter.h
+- Added `GetColumnStatistics()`, `GetStripeColumnStatistics()`, `GetORCType()` methods
+- Implemented statistics conversion for integer, double, and string types
+- Wraps liborc::Statistics with Arrow conventions
 
 **Files modified**:
 - cpp/src/arrow/adapters/orc/adapter.h
 - cpp/src/arrow/adapters/orc/adapter.cc
 
-**Commit status**:
-- Local commit created: b36d1ed9df
-- Branch: task-0-column-statistics-apis
-- Push blocked: Network proxy issue (403 tunnel failed)
+#### Task #1: Add OrcSchemaManifest and OrcSchemaField structures
+**Status**: ✅ COMPLETE - Merged via PR #4
+
+**Changes made**:
+1. Added `OrcSchemaField` struct in file_orc.h
+   - Maps Arrow fields to ORC column indices
+   - Supports nested types via children vector
+   - Column index only set for leaf nodes
+   - Includes is_leaf() helper method
+
+2. Added `OrcSchemaManifest` struct in file_orc.h
+   - Bridges ORC schema and Arrow Schema
+   - Contains origin_schema, schema_fields
+   - Maps for column_index_to_field and child_to_parent
+   - GetColumnField() and GetParent() helper methods
+   - Make() static method (stub implementation)
+
+3. Added stub Make() implementation in file_orc.cc
+   - Returns NotImplemented
+   - Full logic to be implemented in Task #2
+
+**Design**:
+- Mirrors Parquet's SchemaManifest pattern
+- Adapted for ORC's depth-first pre-order type tree (column 0 = root struct)
+- Added necessary includes (unordered_map, vector, status.h, type_fwd.h)
+
+**Files modified**:
+- cpp/src/arrow/dataset/file_orc.h (+69 lines)
+- cpp/src/arrow/dataset/file_orc.cc (+10 lines)
+
+**Verification**:
+- Manual code review: ✅ No syntax errors
+- Build verification: ⏳ Pending (build environment configuration issues)
+
+### Session Statistics
+- Tasks completed: 2 (Tasks #0, #1)
+- PRs created and merged: 4 (PRs #2, #3, #4, #5)
+- Files modified: 4 files across 2 tasks
+
+### Next Task: Task #2
+**Task**: Implement BuildOrcSchemaManifest function
+**Status**: Ready to start (depends on Task #1 which is complete)
+**Priority**: P0
+
+### Build Environment Notes
+- CMake build directory has configuration issues
+- Missing dependencies: Protobuf, RapidJSON
+- Build verification deferred until environment fixed
+- Code changes reviewed manually and appear correct
 
-**Next steps**:
-- Push branch to remote when network access available
-- Create PR and merge
-- Verify compilation in clean build environment
-- Task 0.5: Implement stripe-selective record batch generation
+### Workflow Notes
+- Following PR-based workflow successfully
+- All changes going through PRs (code + status updates)
+- Using personal fork (cbb330/arrow) as working repository
+- GitHub account: cbb330 (personal account)