test_maintenance.py

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import random

import pyarrow as pa

from pyiceberg.catalog import Catalog
from pyiceberg.exceptions import NoSuchNamespaceError
from pyiceberg.partitioning import PartitionField, PartitionSpec
from pyiceberg.schema import Schema
from pyiceberg.transforms import IdentityTransform


def test_maintenance_compact(catalog: Catalog) -> None:
    # Setup Schema and specs
    from pyiceberg.types import LongType, NestedField, StringType

    schema = Schema(
        NestedField(1, "id", LongType()),
        NestedField(2, "category", StringType()),
        NestedField(3, "value", LongType()),
    )
    spec = PartitionSpec(PartitionField(source_id=2, field_id=1000, transform=IdentityTransform(), name="category"))

    # Create the namespace and table
    try:
        catalog.create_namespace("default")
    except NoSuchNamespaceError:
        pass
    table = catalog.create_table(
        "default.test_compaction",
        schema=schema,
        partition_spec=spec,
    )

    # Append many small data files
    categories = ["cat1", "cat2", "cat3"]
    for i in range(12):
        table.append(
            pa.table(
                {
                    "id": list(range(i * 10, (i + 1) * 10)),
                    "category": [categories[i % 3]] * 10,
                    "value": [random.randint(1, 100) for _ in range(10)],
                }
            )
        )

    # Verify state before compaction
    before_files = list(table.scan().plan_files())
    assert len(before_files) == 12
    arrow_table_before = table.scan().to_arrow()
    assert arrow_table_before.num_rows == 120

    # Execute Compaction
    table.maintenance.compact()

    # Verify state after compaction
    table.refresh()
    after_files = list(table.scan().plan_files())
    assert len(after_files) == 3  # Should be 1 optimized data file per partition

    arrow_table_after = table.scan().to_arrow()
    assert arrow_table_after.num_rows == 120
    assert arrow_table_before.column_names == arrow_table_after.column_names
    assert sorted(arrow_table_before.to_pylist(), key=lambda x: x["id"]) == sorted(
        arrow_table_after.to_pylist(), key=lambda x: x["id"]
    )

    # Ensure snapshot properties specify the replace-operation
    new_snapshot = table.current_snapshot()
    assert new_snapshot is not None
    assert new_snapshot.summary is not None
    assert new_snapshot.summary.get("snapshot-type") == "replace"
    assert new_snapshot.summary.get("replace-operation") == "compaction"


def test_maintenance_compact_empty_table(catalog: Catalog) -> None:
    from pyiceberg.types import LongType, NestedField, StringType

    schema = Schema(
        NestedField(1, "id", LongType()),
        NestedField(2, "category", StringType()),
    )

    try:
        catalog.create_namespace("default")
    except NoSuchNamespaceError:
        pass

    table = catalog.create_table("default.test_compaction_empty", schema=schema)
    before_snapshots = len(table.history())

    # Should safely return doing nothing
    table.maintenance.compact()

    table.refresh()
    after_snapshots = len(table.history())
    assert before_snapshots == after_snapshots  # No new snapshot should be made