chore: retire the Iceberg backend

CLAUDE.md

@@ -4,7 +4,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Project Overview
 
-**mountainash-data** provides physical access to backend data services — relational databases via Ibis, and Iceberg table-format catalogs via PyIceberg. It collapses what was previously 13 per-dialect connection classes into a data-driven `DialectSpec` registry, exposes clean `Backend` / `Connection` protocols, and provides factories and a high-level facade (`DatabaseUtils`).
+**mountainash-data** provides physical access to backend data services — relational databases via Ibis behind a backend-agnostic `Backend` protocol ready for additional backends. It collapses what was previously 13 per-dialect connection classes into a data-driven `DialectSpec` registry, exposes clean `Backend` / `Connection` protocols, and provides factories and a high-level facade (`DatabaseUtils`).
 
 ## Planning, Specs & Principles (live in mountainash-central)
 
@@ -63,11 +63,6 @@ tests, and this `CLAUDE.md` live in this repo's tree.
    - `BaseIbisOperations` + per-dialect subclasses in `operations.py`
    - `DialectSpec` registry in `dialects/`
 
-7. **Iceberg backend** (`src/mountainash_data/backends/iceberg/`)
-   - `IcebergBackend` — catalog-type registry (currently: `"rest"`)
-   - Connection, operations, and inspection classes
-   - Requires optional `pyiceberg` dependency
-
 ### Package Structure
 
 ```
@@ -83,22 +78,15 @@ src/mountainash_data/
 │   ├── settings/                # Per-dialect auth settings (pydantic)
 │   └── factories/               # ConnectionFactory, OperationsFactory, SettingsFactory
 └── backends/
-    ├── ibis/
-    │   ├── backend.py           # IbisBackend + IbisConnection (new-style)
-    │   ├── connection.py        # BaseIbisConnection + dialect subclasses
-    │   ├── operations.py        # BaseIbisOperations + dialect subclasses
-    │   ├── inspect.py           # Ibis-specific inspection helpers
-    │   └── dialects/            # DialectSpec registry (data-driven)
-    └── iceberg/
-        ├── backend.py           # IcebergBackend + catalog registry
-        ├── connection.py        # IcebergConnectionBase
-        ├── operations.py        # IcebergOperationsBase
-        ├── inspect.py           # Iceberg inspection helpers
-        └── catalogs/            # Per-catalog implementations
+    └── ibis/
+        ├── backend.py           # IbisBackend + IbisConnection (new-style)
+        ├── connection.py        # BaseIbisConnection + dialect subclasses
+        ├── operations.py        # BaseIbisOperations + dialect subclasses
+        ├── inspect.py           # Ibis-specific inspection helpers
+        └── dialects/            # DialectSpec registry (data-driven)
 ```
 
 ### Optional Dependencies (extras)
-- **pyiceberg**: Required for `IcebergBackend`
 - **postgres**: PostgreSQL support (psycopg2-binary, ibis-framework[postgres])
 - **mssql**: SQL Server support (pyodbc, ibis-framework[mssql])
 - **snowflake**: Snowflake support (snowflake-connector-python, ibis-framework[snowflake])
@@ -196,7 +184,6 @@ tests/
 ├── test_unit/
 │   ├── core/                      # Protocol, inspection tests
 │   ├── backends/ibis/             # IbisBackend tests
-│   ├── backends/iceberg/          # IcebergBackend tests
 │   ├── factories/                 # Factory tests
 │   ├── databases/                 # Legacy-path tests (updated to new paths)
 │   ├── test_database_utils.py     # DatabaseUtils tests
@@ -219,7 +206,7 @@ tests/
 ## Usage Patterns
 
 ```python
-from mountainash_data import IbisBackend, IcebergBackend
+from mountainash_data import IbisBackend
 from mountainash_data.core.settings import (
     SQLiteAuthSettings,
     NoAuth,
@@ -250,14 +237,6 @@ try:
     #   rel = ma.relation(ibis_table)  # compiles against Ibis automatically
 finally:
     conn.close()
-
-# Iceberg backend (requires pyiceberg)
-ice = IcebergBackend(catalog="rest", uri="http://localhost:8181")
-ice_conn = ice.connect()
-try:
-    namespaces = ice_conn.list_namespaces()
-finally:
-    ice_conn.close()
 ```
 
 ## Development Environments

README.md

@@ -6,7 +6,7 @@
 Mountain Ash - Data
 
 Physical access to backend data services — relational databases via Ibis,
-and Iceberg table-format catalogs via PyIceberg.
+behind a backend-agnostic `Backend` protocol ready for additional backends.
 
 
 
@@ -83,18 +83,12 @@ src/mountainash_data/
 │   ├── settings/                # Per-dialect auth settings (pydantic)
 │   └── factories/               # ConnectionFactory, OperationsFactory, SettingsFactory
 └── backends/
-    ├── ibis/                    # IbisBackend — 12-dialect registry
-    │   ├── backend.py           # IbisBackend + IbisConnection
-    │   ├── connection.py        # BaseIbisConnection + per-dialect subclasses
-    │   ├── operations.py        # BaseIbisOperations + per-dialect subclasses
-    │   ├── inspect.py           # Ibis-specific inspection helpers
-    │   └── dialects/            # DialectSpec registry (data-driven)
-    └── iceberg/                 # IcebergBackend — PyIceberg catalogs
-        ├── backend.py           # IcebergBackend + catalog registry
-        ├── connection.py        # IcebergConnectionBase
-        ├── operations.py        # IcebergOperationsBase
-        ├── inspect.py           # Iceberg inspection helpers
-        └── catalogs/            # Per-catalog implementations (rest, …)
+    └── ibis/                    # IbisBackend — 12-dialect registry
+        ├── backend.py           # IbisBackend + IbisConnection
+        ├── connection.py        # BaseIbisConnection + per-dialect subclasses
+        ├── operations.py        # BaseIbisOperations + per-dialect subclasses
+        ├── inspect.py           # Ibis-specific inspection helpers
+        └── dialects/            # DialectSpec registry (data-driven)
 ```
 
 ### Public API
@@ -104,7 +98,6 @@ from mountainash_data import (
     Backend,            # Protocol: what every backend must implement
     Connection,         # Protocol: what every connection must implement
     IbisBackend,        # Ibis-style relational backends (sqlite, duckdb, postgres, …)
-    IcebergBackend,     # Iceberg-style table-format catalogs (pyiceberg required)
     CatalogInfo,        # Physical catalog metadata
     NamespaceInfo,      # Physical namespace/schema metadata
     TableInfo,          # Physical table metadata
@@ -118,7 +111,6 @@ from mountainash_data import (
 
 ### Optional Dependencies
 
-- **pyiceberg**: Required for `IcebergBackend`. Not installed by default.
 - **postgres**: `psycopg2-binary` + `ibis-framework[postgres]`
 - **mssql**: `pyodbc` + `ibis-framework[mssql]`
 - **snowflake**: `snowflake-connector-python` + `ibis-framework[snowflake]`

docs/PROJECT_OVERVIEW.md

@@ -5,7 +5,7 @@ Provides unified database connections and dataframe abstractions for multiple ba
 
 ## Architecture
 The package is built on a layered architecture with three main components:
-1. **Database Connections Layer** - Abstracts database connections using Ibis framework and PyIceberg
+1. **Database Connections Layer** - Abstracts database connections using the Ibis framework
 2. **DataFrame Abstraction Layer** - Provides unified dataframe interface across multiple backends
 3. **Utilities Layer** - Supporting utilities for data transformation, mapping, and conversion
 
@@ -17,31 +17,25 @@ src/mountainash_data/
 ├── databases/                     # Database connection layer
 │   ├── __init__.py
 │   ├── base_db_connection.py     # Abstract base connection
-│   ├── ibis/                     # Ibis-based connections
-│   │   ├── __init__.py
-│   │   ├── base_ibis_connection.py
-│   │   ├── constants.py
-│   │   ├── ibis_connection_factory.py
-│   │   └── connections/          # Specific backend implementations
-│   │       ├── __init__.py
-│   │       ├── bigquery_ibis_connection.py
-│   │       ├── duckdb_ibis_connection.py
-│   │       ├── motherduck_ibis_connection.py
-│   │       ├── mssql_ibis_connection.py
-│   │       ├── mysql_ibis_connection.py
-│   │       ├── oracle_ibis_connection.py
-│   │       ├── postgres_ibis_connection.py
-│   │       ├── pyspark_ibis_connection.py
-│   │       ├── redshift_ibis_connection.py
-│   │       ├── snowflake_ibis_connection.py
-│   │       ├── sqlite_ibis_connection.py
-│   │       └── trino_ibis_connection.py
-│   └── pyiceberg/               # PyIceberg support
+│   └── ibis/                     # Ibis-based connections
 │       ├── __init__.py
-│       ├── base_pyiceberg_connection.py
-│       └── connections/
+│       ├── base_ibis_connection.py
+│       ├── constants.py
+│       ├── ibis_connection_factory.py
+│       └── connections/          # Specific backend implementations
 │           ├── __init__.py
-│           └── pyiceberg_rest_connection.py
+│           ├── bigquery_ibis_connection.py
+│           ├── duckdb_ibis_connection.py
+│           ├── motherduck_ibis_connection.py
+│           ├── mssql_ibis_connection.py
+│           ├── mysql_ibis_connection.py
+│           ├── oracle_ibis_connection.py
+│           ├── postgres_ibis_connection.py
+│           ├── pyspark_ibis_connection.py
+│           ├── redshift_ibis_connection.py
+│           ├── snowflake_ibis_connection.py
+│           ├── sqlite_ibis_connection.py
+│           └── trino_ibis_connection.py
 ├── dataframes/                   # DataFrame abstraction layer
 │   ├── __init__.py
 │   ├── base_dataframe.py        # Abstract dataframe interface
@@ -101,7 +95,6 @@ Core package providing unified data access layer with key classes:
 Database connection abstraction supporting multiple backends:
 - **Base Layer**: `BaseDBConnection` abstract interface
 - **Ibis Layer**: Connection implementations for 12+ database backends
-- **PyIceberg Layer**: Data lake connectivity via Apache Iceberg
 
 ### dataframes/
 DataFrame abstraction and utilities:

docs/assets/package_overview.md

@@ -9,7 +9,6 @@
 1. **Database Connections Layer** (`src/mountainash_data/databases/`)
    - Base database connection abstraction (`BaseDBConnection`)
    - Ibis-based connections supporting multiple backends (SQLite, DuckDB, PostgreSQL, SQL Server, etc.)
-   - PyIceberg support for data lake operations
    - Connection factory pattern for backend instantiation
 
 2. **DataFrame Abstraction Layer** (`src/mountainash_data/dataframes/`)
@@ -43,7 +42,6 @@ src/mountainash_data/
 │   │   │   ├── postgres_ibis_connection.py
 │   │   │   └── [other backends...]
 │   │   └── ibis_connection_factory.py
-│   └── pyiceberg/               # PyIceberg support
 ├── dataframes/                   # DataFrame abstraction layer
 │   ├── base_dataframe.py        # Abstract dataframe interface
 │   ├── ibis_dataframe.py        # Ibis dataframe implementation

docs/dbt_integration.md

@@ -526,7 +526,7 @@
   | Snapshots          | mountainash-data       | mountainash-dataframes | Operations + Join for SCD           |
   | Seeds (Enhanced)   | mountainash-dataframes | -                      | Convert from structured Python data |
   | Materializations   | mountainash-data       | -                      | Connection, Operations              |
-  | External Tables    | mountainash-data       | mountainash-dataframes | PyIceberg, External file ops        |
+  | External Tables    | mountainash-data       | mountainash-dataframes | External file ops                   |
 
   ---
   🎯 Integration Architecture Pattern
@@ -598,7 +598,6 @@
 
   Phase 4: Advanced Features (Innovation)
   9. ✅ Custom materializations using mountainash-data connections
-  10. ✅ PyIceberg integration for data lakes
 
   ---
   This alignment creates a powerful synergy where:
@@ -1640,7 +1639,6 @@
   - ✅ PostgreSQL, MySQL, Oracle, MS SQL Server
   - ✅ Snowflake, BigQuery, Redshift
   - ✅ PySpark, Trino
-  - ✅ PyIceberg (data lakes)
 
   dbt Integration Points:
   - ✅ Incremental model upserts

docs/quickstart.md

@@ -15,7 +15,6 @@ pip install mountainash-data[snowflake]    # Snowflake
 pip install mountainash-data[bigquery]     # BigQuery
 pip install mountainash-data[pyspark]      # Apache Spark
 pip install mountainash-data[trino]        # Trino
-pip install mountainash-data[pyiceberg]    # Iceberg catalogs
 ```
 
 SQLite and DuckDB work out of the box — no extra needed.
@@ -214,17 +213,3 @@ with IbisBackend(dialect="duckdb") as backend:
 | `druid` | `druid://` | |
 | `pyspark` | `pyspark://` | Requires `[pyspark]` extra |
 
----
-
-## Iceberg catalogs (optional)
-
-Requires `pip install mountainash-data[pyiceberg]`.
-
-```python
-from mountainash_data import IcebergBackend
-
-with IcebergBackend(catalog="rest", uri="http://localhost:8181") as backend:
-    namespaces = backend.list_namespaces()
-    tables = backend.list_tables(namespace="analytics")
-    info = backend.inspect_table("events", namespace="analytics")
-```

pyproject.toml

@@ -102,18 +102,8 @@ exclude_lines = ["no cov", "if __name__ == .__main__:", "if TYPE_CHECKING:"]
 
 [tool.mypy]
 # Internal mountainash siblings ship no py.typed marker, and optional drivers
-# (trino/google/pyiceberg/mountainash_dataframes) are not installed in the type
+# (trino/google/mountainash_dataframes) are not installed in the type
 # env — treat all unresolved/untyped third-party imports as Any rather than noise.
 ignore_missing_imports = true
 disable_error_code = ["import-untyped"]
 
-# Pre-existing type debt in the Iceberg backend (catalog_backend None-narrowing,
-# pyiceberg Any-typed surfaces, hook-signature mismatches) — NOT introduced by
-# the auth-client migration and in code paths that require the optional pyiceberg
-# + mountainash_dataframes stack to exercise. Carved out for a separate Iceberg
-# type-hardening pass; the auth-migration code (factories/adapters/registry/ibis)
-# is type-checked normally.
-[[tool.mypy.overrides]]
-module = "mountainash_data.backends.iceberg.*"
-ignore_errors = true
-

src/mountainash_data/__init__.py

@@ -3,7 +3,6 @@
 Public API:
     Backend — protocol (core.protocol)
     IbisBackend — ibis-style relational backends (backends.ibis.backend)
-    IcebergBackend — iceberg-style table-format catalogs (backends.iceberg.backend)
     CatalogInfo, NamespaceInfo, TableInfo, ColumnInfo — inspection model
 """
 
@@ -18,11 +17,6 @@
 from mountainash_data.core.namespace import Namespace, NamespaceLike
 from mountainash_data.backends.ibis.backend import IbisBackend
 
-try:
-    from mountainash_data.backends.iceberg.backend import IcebergBackend
-except ImportError:
-    IcebergBackend = None  # type: ignore[assignment,misc]
-
 __all__ = [
     "__version__",
     "Backend",
@@ -33,5 +27,4 @@
     "Namespace",
     "NamespaceLike",
     "IbisBackend",
-    "IcebergBackend",
 ]