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Jack Ye
ddb318567a
## Summary - Complete the SQL reference: `ATTACH DATABASE`, the `CHANGES` clause, and `dedupe()`/`duplicate_pairs()` (verified against current sophon source; these were recently renamed from `vector_dedup`/`vector_duplicate_pairs`). Fix the blob-column default-projection claim and add the previously undocumented `blob_descriptor()`. - Enrich the gated Functions draft (still `.mintignore`'d, pre-release): chained Functions over blob outputs, GPU-produced blobs, Secrets, multi-input/output binding, `code=[module]` packaging. - Upgrade the materialized-view and computed-column auto-refresh drafts with precise, verified catch-up semantics, and add the missing `ALTER MATERIALIZED VIEW` / `CREATE ... WITH(...)` sections (also gated — the automatic-refresh scheduler is still dev/staging-only). - Thread one running example (video frames → GPU extract/caption → dedup → auto-refreshing materialized view) through Functions, materialized views, and the LeRobotDataset integration guide instead of a separate tutorial. - Rename "LanceDB OSS"/"OSS" to "LanceDB Embedded"/"Embedded" throughout (52 files); activate the existing availability-comparison mechanism on `basics/offerings.mdx` for a full feature-by-feature comparison table.
89 lines
2.8 KiB
Plaintext
89 lines
2.8 KiB
Plaintext
---
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title: "Refresh a materialized view"
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sidebarTitle: "Refresh Materialized View"
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description: "Bring a materialized view up to date after its source data changes."
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icon: arrows-rotate
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keywords: ["materialized view", "refresh", "auto_refresh_enabled", "auto_refresh_interval_seconds"]
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availability:
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embedded: unavailable
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enterprise: available
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---
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Refresh a [materialized view](/feature-engineering/materialized-views) to
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bring its stored rows up to date after the source table changes.
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<Note>
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In SQL this is [`REFRESH MATERIALIZED VIEW`](/sql/dml/refresh-materialized-view).
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</Note>
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## Refresh a view {#refresh}
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```python
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view.refresh()
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```
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Every refresh rebuilds the view completely from its source query -- there is
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no incremental refresh. Calling it again with no source changes still
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rebuilds and commits a new table version.
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The result reports what the refresh did:
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```python
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result = view.refresh()
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result.rows_written # rows in the rebuilt view
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result.source_version # the source table version the view now reflects
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result.version # the view's own new table version
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```
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Pass `source_version=N` to refresh against a particular source version
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instead of the latest:
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```python
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view.refresh(source_version=12)
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```
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Use `view.table.count_rows()` for the view's row count at any time; it
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always matches `rows_written` from the most recent refresh.
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## Automatic refresh {#auto-refresh}
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Set scheduling options when [creating the view](/feature-engineering/materialized-views#auto-refresh):
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```python
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view = db.create_materialized_view(
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"frames_captioned",
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source="frames",
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select=["frame_id", "video_id", "ts", "caption"],
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where="selected = true",
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auto_refresh_enabled=True,
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auto_refresh_interval_seconds=300,
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)
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```
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`auto_refresh_interval_seconds` is a positive minimum delay after the last
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successful refresh before the next automatic one is eligible; omit it to let
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the server decide. The whole view toggles together -- there is no
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per-column granularity the way a computed column has one setting per output.
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The view's *initial* population, at creation or when the server first runs
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it, happens regardless of these settings; only refreshes after that are
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gated. Manual `view.refresh()` keeps working whether or not automatic
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refresh is enabled.
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## When a refresh fails {#failures}
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A refresh replaces the view's stored rows in one commit, so a failure leaves
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the view as it was after its last successful refresh. Fix the cause and
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refresh again.
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## Related guides {#next}
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<CardGroup cols={2}>
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<Card title="Create a materialized view" icon="table" href="/feature-engineering/materialized-views">
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Define the query a view stores.
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</Card>
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<Card title="Refresh a computed column" icon="arrows-rotate" href="/feature-engineering/refresh-column">
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The same idea, for a single derived column.
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</Card>
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</CardGroup>
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