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Brendan Clement
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This PR is part of the documentation revamp. Once the full set of PRs is merged, we’ll publish the combined site to staging for review before updating docs.lancedb.com. The curation, SQL and operations pages contain outdated claims and examples that do not reliably work as written. This corrects those pages against the reviewed SDK and local server evidence, including prepared statements, background jobs, cleanup and monitoring. Integration guides are grouped with their examples in #4533. Function and Secret-object documentation stays unpublished until its release. The two Function pages are listed in `.mintignore` and left out of the navigation, and the sections about them on other pages are MDX comments. Stacked on #4533. Each MDX file has one PR owner. Rebase onto main after #4533 is squash-merged. Local assembly, Mint validation and link checks pass, and the assembled site shows no Function or Secret-object content. A local release rehearsal that uncomments the drafts and restores the navigation also passes. Hold publication until this PR and lancedb/sophon#8688 are on `main`.
107 lines
4.5 KiB
Plaintext
107 lines
4.5 KiB
Plaintext
---
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title: "SQL reference"
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sidebarTitle: "Overview"
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description: "SQL statements, expressions and data types supported by LanceDB Enterprise."
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icon: table-list
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keywords: ["sql", "datafusion", "flight sql", "reference", "dialect"]
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---
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LanceDB Enterprise supports SQL through an Arrow Flight SQL endpoint. This
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reference covers statement syntax, data types and expressions. To set up a
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client and run your first query, see [SQL](/basics/sql).
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## The dialect {#dialect}
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LanceDB uses [Apache DataFusion](https://datafusion.apache.org) for SQL planning
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and execution. These pages describe LanceDB's supported statements and
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extensions. DataFusion's reference is useful for expression syntax, but does
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not establish that every DataFusion statement or feature is exposed by
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LanceDB.
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## Connecting {#connecting}
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Use Python's `execute_query` or a Flight SQL client after configuring the
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[Enterprise connection](/basics/sql#sql-is-remote). TypeScript applications
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use a Flight SQL client for SQL queries.
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```python
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reader = db.execute_query("SELECT id, text FROM my_docs LIMIT 10")
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for batch in reader:
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print(batch)
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```
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SQL results arrive as Arrow record batches. Iterating over the reader avoids
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collecting the entire result in application memory. See
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[Queries](/basics/query) for result handling.
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## Usage {#usage}
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The endpoint executes one statement per request and is meant for the queries
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and DDL/DML pages below. Reach for the SDKs instead for table-management
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operations that have no SQL form, such as a merge insert -- see
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[What SQL cannot do](#cannot).
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## Reference {#reference}
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### DDL, by object {#ddl}
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| [Namespace](/sql/ddl/namespace) | `CREATE SCHEMA`, `DROP SCHEMA` |
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| [Table](/sql/ddl/table) | `CREATE`, `DESCRIBE`, `ALTER`, `CLONE`, `DROP TABLE` |
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| [View](/sql/ddl/view) | `CREATE VIEW`, `DROP VIEW` |
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| [Materialized view](/sql/ddl/materialized-view) | `CREATE MATERIALIZED VIEW`, `SHOW MATERIALIZED VIEWS` |
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| [Index](/sql/ddl/index) | `CREATE INDEX`, `DROP INDEX` |
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| [Job](/sql/ddl/job) | `SHOW JOBS`, `SHOW ERRORS`, `PAUSE`/`RESUME`/`CANCEL JOB` |
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{/*
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Draft for the Functions release. Add this row to the table above, after Index:
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| [Function](/sql/ddl/function) | `CREATE FUNCTION`, `SHOW FUNCTIONS`, `DROP FUNCTION` |
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*/}
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### DML {#dml}
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| --- | --- |
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| [Insert](/sql/dml/insert) | `INSERT INTO`, including `INSERT ... SELECT` |
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| [Update](/sql/dml/update) | `UPDATE ... SET` |
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| [Delete](/sql/dml/delete) | `DELETE FROM` |
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| [Copy](/sql/dml/copy) | `COPY` -- refused by recent deployment versions |
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| [Refresh](/sql/dml/refresh) | filling computed columns and materialized views |
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### DQL {#dql}
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| --- | --- |
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| [Data types](/sql/data-types) | how Lance columns appear to SQL, and pseudo-columns |
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| [Select](/sql/dql/select) | projection, filtering, ordering, set operations, CTEs |
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| [Subqueries](/sql/dql/subqueries) | scalar, `IN`, `EXISTS`, correlated, derived tables |
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| [Joins](/sql/dql/join) | inner, outer, cross, and namespace-qualified paths |
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| [Aggregation](/sql/dql/aggregation) | `GROUP BY`, `HAVING`, the aggregate set |
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| [Window functions](/sql/dql/window) | `OVER`, framing, ranking and offset functions |
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| [Sampling](/sql/dql/sampling) | `TABLESAMPLE`, by rows or by fragments |
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| [Full-Text Search](/sql/dql/fts) | the `fts()` table function, and its query forms |
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| [Explain](/sql/dql/explain) | `EXPLAIN`, `EXPLAIN ANALYZE`, `EXPLAIN VERBOSE` |
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### Expressions {#expressions}
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| --- | --- |
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| [Operators](/sql/operators) | comparison, logical, arithmetic, literals, precedence |
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| [Functions](/sql/functions) | where to find each kind, and table functions |
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| [Scalar functions](/sql/scalar-functions) | the per-row catalogue, and what Lance accelerates |
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| [Prepared statements](/sql/prepared-statements) | preparing through a Flight SQL client |
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## SQL limitations and alternatives {#cannot}
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| --- | --- |
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| Vector search | See [SQL vector search](/basics/sql#no-vector-sql) for supported query forms and server-version requirements. The [SDK query builder](/search/vector-search) also supports vector search. |
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| Merge insert | no SQL form -- needs a source relation and a per-match policy |
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| `information_schema` | not enabled, so `SHOW TABLES` and `SHOW COLUMNS` fail |
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| `COPY` | refused by recent deployment versions -- see [Copy](/sql/dml/copy) |
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| `PREPARE` / `EXECUTE` | preparation is a [protocol feature](/sql/prepared-statements), not a statement |
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| Run on a local database | no engine to plan the statement |
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See [Limits](/basics/limits#sql) for the bounds these pages enforce.
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