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https://github.com/lancedb/lancedb.git
synced 2026-10-14 15:52:26 +00:00
Brendan Clement
69f11c259d
Since lancedb#4180, create_materialized_view runs the initial refresh before it returns (with_no_data=True skips it), so the page's first manual refresh now writes 0 rows, not 1. The example now reads the populated view and refreshes after a source change, and its snippets come from docs/web-tests/py/test_materialized_view.py. A note scopes the behavior: 0.39 and earlier create the view empty. Pages that said a refresh computes the rows now say it brings them up to date, and the SQL note no longer says an incremental refresh covers only added rows.
58 lines
1.6 KiB
Python
58 lines
1.6 KiB
Python
# SPDX-License-Identifier: Apache-2.0
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# SPDX-FileCopyrightText: Copyright The LanceDB Authors
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"""Examples for docs/web/feature-engineering/materialized-views.mdx."""
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def test_materialized_view_create_and_refresh(tmp_path, monkeypatch):
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monkeypatch.chdir(tmp_path)
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# --8<-- [start:materialized_view_create]
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import lancedb
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db = lancedb.connect(
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"./.lancedb",
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storage_options={"new_table_enable_stable_row_ids": "true"},
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)
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table = db.create_table(
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"people", [{"name": "ada", "age": 36}, {"name": "kid", "age": 7}]
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)
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view = db.create_materialized_view(
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"adults",
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"people",
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select=["name", ("shout", "upper(name)")],
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where="age >= 18",
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)
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print(view.table.count_rows())
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# 1
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# --8<-- [end:materialized_view_create]
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assert view.table.count_rows() == 1
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# --8<-- [start:materialized_view_refresh]
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table.add([{"name": "bea", "age": 41}])
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result = view.refresh()
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print(result.rows_written)
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# 1
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# --8<-- [end:materialized_view_refresh]
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assert result.rows_written == 1
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assert sorted(row["shout"] for row in view.table.to_arrow().to_pylist()) == [
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"ADA",
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"BEA",
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]
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def test_materialized_view_with_no_data(tmp_path):
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import lancedb
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db = lancedb.connect(
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tmp_path, storage_options={"new_table_enable_stable_row_ids": "true"}
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)
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db.create_table("people", [{"name": "ada", "age": 36}])
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view = db.create_materialized_view(
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"adults", "people", where="age >= 18", with_no_data=True
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)
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assert view.table.count_rows() == 0
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assert view.refresh().rows_written == 1
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