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Jack YeandClaude Sonnet 5
de95ed3f6d
A broad documentation pass across the areas LanceDB Enterprise and Embedded diverge on most: **Data Curation** -- GPU Function execution, Slurm scheduling (and what Slurm is, for readers new to it), blob late materialization as its own page, joins, aggregation/profiling, sampling, near-duplicate detection, chunking, distributed shuffle, and IVF-partition clustering. **Feature Engineering** -- computed columns and materialized views, restructured to lead with the Function-based path and show the SQL form side by side with Python throughout; a single Auto Refresh page instead of duplicating scheduling details on every refresh page; adaptive execution; checkpointing; GPU and Slurm placement for refresh workers; a Training Cache page for the PyTorch data loader's automatic cache benefit. **Security & Governance** -- an Audit Log reference (schema, access, grants), Secrets promoted to an ordinary catalog object with their own SQL DDL and a vending/rotation guide, and privilege-table fixes verified against the authorization source. **Deployment & Maintenance** -- Horizontal Scaling and OpenTelemetry moved into a real Deployment area; Automated Cleanup folded into Intelligent Auto-Maintenance (every other maintenance decision already lived there); RTE Compaction and Advanced Conflict Resolution documented in depth. **Landing page** -- the Enterprise feature comparison table reorganized (several redundant or stale rows removed, several new areas added), and the "why Enterprise" bullets replaced with ones tied to a concrete page (Performance, Scale, Fault tolerance, Multicloud deployment, Simplify operations) instead of vague promises. Plus a full pass addressing lancedb-gatekeeper's review: a real test-safety bug (a quickstart test could silently overwrite and delete a deployment's own `frames` table), a fabricated SQL statement with no backing implementation, an actual dedup-guarantee bug in `take_row_ids`, and dozens of documentation-accuracy fixes verified against source rather than taken on faith -- each either fixed, or left with an explicit note on why it needs a feature or deployment owner's sign-off instead of being guessed at. 🤖 Generated with [Claude Code](https://claude.com/claude-code) https://claude.ai/code/session_018PXMCbRH6i5w47TsjeEUMT --------- Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
81 lines
2.8 KiB
Plaintext
81 lines
2.8 KiB
Plaintext
---
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title: "Changes since a version"
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sidebarTitle: "Changes"
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description: "CHANGES: read the rows appended to a table since an earlier version."
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icon: clock-rotate-left
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keywords: ["changes", "append", "incremental", "cdc", "version"]
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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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`CHANGES` reads the rows appended to a table since an earlier
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[version](/management/table#versioning), without rescanning rows that were
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already there:
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<CodeGroup>
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```sql SQL icon="database"
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SELECT * FROM events CHANGES (INFORMATION => APPEND_ONLY) AT (VERSION => 42)
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```
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</CodeGroup>
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This returns the rows appended after version 42, up to the table's current
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version at the time the query runs.
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## Strictly append-only {#strict}
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The clause is named for what it requires, not just what it does: every
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change to the table between the starting version and the current one must
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be an append. If any of them inserted with changes other than a pure append
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-- an update, a delete, a merge -- the query is refused rather than silently
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returning an incomplete or wrong result. Re-run it with a later starting
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version that is itself after the non-append write, or read the table in full
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instead of incrementally.
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`INFORMATION => APPEND_ONLY` is the only supported value: it names what kind
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of history the clause is willing to read, not a choice among several. `AT
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(VERSION => ...)` takes a positive integer; there is no `AT (TIMESTAMP =>
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...)` form for this clause, unlike other version qualifiers.
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## Where the clause can go {#placement}
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It attaches to a table in `FROM`, including inside a subquery, a CTE, a join,
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a set operation, or `EXPLAIN`:
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<CodeGroup>
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```sql SQL icon="database"
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WITH recent AS (
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SELECT * FROM events CHANGES (INFORMATION => APPEND_ONLY) AT (VERSION => 42)
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)
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SELECT count(*) FROM recent
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SELECT * FROM events CHANGES (INFORMATION => APPEND_ONLY) AT (VERSION => 10) a
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JOIN events CHANGES (INFORMATION => APPEND_ONLY) AT (VERSION => 20) b
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ON a.id = b.id
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```
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</CodeGroup>
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Each occurrence of a table keeps its own starting version, even when the same
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table is referenced more than once in one statement.
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## Unsupported forms {#refused}
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| --- | --- |
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| `CHANGES (INFORMATION => DEFAULT)` | only `APPEND_ONLY` is supported |
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| `AT (TIMESTAMP => ...)` | only `AT (VERSION => ...)` is supported |
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| `AT (VERSION => 0)` | the starting version must be positive |
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| `... END (VERSION => ...)` | not supported; the current version is always the end |
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| `CHANGES ... TABLESAMPLE (...)` | cannot be combined on the same table reference |
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## What to read next {#next}
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<CardGroup cols={2}>
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<Card title="Table" icon="table" href="/sql/ddl/table">
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CREATE, ALTER, CLONE and versioning basics.
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</Card>
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<Card title="Select" icon="magnifying-glass" href="/sql/dql/select">
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The rest of the query grammar this clause attaches to.
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</Card>
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</CardGroup>
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