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Jack Ye
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## 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.
109 lines
4.3 KiB
Plaintext
109 lines
4.3 KiB
Plaintext
---
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title: "Delete rows"
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sidebarTitle: "Delete"
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description: "Select and delete records, verify the remaining rows, and understand storage retention."
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icon: trash
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availability:
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embedded: available
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enterprise: available
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---
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import { RsExample as RsDeleteRows } from '/snippets/ingestion_delete.mdx';
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import { TsDeleteRowsBody, TsDeleteRowsTail } from '/snippets/ingestion_examples.mdx';
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import { PyDeleteRows } from '/snippets/ingestion_examples.mdx';
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import { PyWriteWorkflow, TsWriteWorkflowBody, TsWriteWorkflowTail, RsWriteWorkflow } from '/snippets/ingestion_examples.mdx';
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Deleting rows removes matching records from the current table contents. It
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keeps the table and schema so you can continue reading and writing. To remove
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the table itself, see [Drop a table](/ingestion/create-table#drop-a-table).
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## Inspect the rows you intend to delete {#select-rows}
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Use the same predicate for inspection and deletion. The example below creates
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Alice, Bob and Charlie, prints Charlie's row, and deletes it by `id = 3`.
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Inspection and deletion are separate operations; concurrent writes can change
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which rows match between them.
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## Delete matching records {#delete-rows}
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Each program creates Alice, Bob and Charlie in a temporary local database,
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deletes Charlie, and prints the remaining rows: **Alice and Bob**. The temporary
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database is removed when the program finishes.
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- **Python:** install `lancedb`, save the code as `delete_rows.py`, and run
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`python delete_rows.py`.
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- **TypeScript:** install `@lancedb/lancedb`, save the code as `delete_rows.mts`,
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and run `node delete_rows.mts` with Node.js 22.18 or later.
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- **Rust:** download the [Rust examples](/static/code/ingestion-feedback-rust.zip),
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extract the project, and run `cargo run --locked --bin delete`.
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<CodeGroup>
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<CodeBlock filename="Python" language="python" icon="python">
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{PyDeleteRows}
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</CodeBlock>
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<CodeBlock filename="TypeScript" language="typescript" icon="square-js">
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{TsDeleteRowsBody}
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{TsDeleteRowsTail}
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</CodeBlock>
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<CodeBlock filename="Rust" language="rust" icon="rust">
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{RsDeleteRows}
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</CodeBlock>
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</CodeGroup>
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Enterprise also supports [`DELETE`](/sql/dml/delete).
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## Verify that the rows are absent {#verify}
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Query the same predicate after deletion and check the remaining row count.
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A reader still using an older snapshot may see the earlier contents; see
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[Consistency](/tables/consistency).
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Deleted rows are excluded from current query results, including indexed
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searches. Deletion does not imply immediate physical erasure of every stored
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copy of the data.
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## Understand storage reclamation {#storage}
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Compaction rewrites the live data layout; cleanup removes eligible retained
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versions and files. Retained history can continue to reference data that no
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longer appears in the latest table version.
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In LanceDB Embedded, `optimize()` provides maintenance operations. In Enterprise, managed
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maintenance and retention follow the service configuration. Choose retention
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according to the history you need, rather than shortening it as part of a
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routine delete example. See [Compaction](/maintenance/compaction) and
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[Cleanup](/maintenance/cleanup) for the separate maintenance workflow.
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## Complete write workflow {#complete-example}
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<Accordion title="Complete examples: create, append, update, upsert and delete">
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Each program creates a temporary local database, performs the five operations,
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prints the result, and removes its temporary data when finished.
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- **Python:** install `lancedb`, save the code as `ingestion.py`, and run
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`python ingestion.py`.
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- **TypeScript:** install `@lancedb/lancedb`, save the code as `ingestion.mts`,
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and run `node ingestion.mts` with Node.js 22.18 or later.
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- **Rust:** download the [complete Rust project](/static/code/ingestion-rust.zip),
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extract it, and run `cargo run --locked`. It includes `src/main.rs`, the Cargo
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manifest and a lockfile for the example's dependencies. The code is shown below.
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<CodeGroup>
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<CodeBlock filename="ingestion.py" language="python" icon="python">
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{PyWriteWorkflow}
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</CodeBlock>
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<CodeBlock filename="ingestion.mts" language="typescript" icon="square-js">
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{TsWriteWorkflowBody}
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{TsWriteWorkflowTail}
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</CodeBlock>
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<CodeBlock filename="src/main.rs" language="rust" icon="rust">
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{RsWriteWorkflow}
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</CodeBlock>
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</CodeGroup>
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After the operations, Alice has 10 logins, Bobby has 21, and Charlie has 6.
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Dana is selected for deletion and is absent from the final result.
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</Accordion>
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