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Jack Ye
52684d50b9
OSS docs now own the full usage content for features that only run against an Enterprise deployment, since the client interface itself lives here; Enterprise docs keep only the parts specific to its own behavior. Sophon's overlay for these five pages is dropped since the OSS versions are now the complete reference. SQL Reference is restructured to match an object-type SQL manual (DDL by object, then DML, then DQL, then Expressions) instead of the old flat, loosely-ordered page list, absorbing the SQL client-connection guide and FTS-via-SQL examples into it.
87 lines
2.8 KiB
Plaintext
87 lines
2.8 KiB
Plaintext
---
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title: "Function"
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sidebarTitle: "Function"
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description: "CREATE FUNCTION, SHOW FUNCTIONS, and DROP FUNCTION."
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icon: function
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keywords: ["create function", "drop function", "show functions", "sql", "udf"]
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---
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<Badge color="red">Enterprise</Badge> [SQL runs on a deployment.](/sql)
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## CREATE FUNCTION {#create}
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```sql
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CREATE FUNCTION f(x BIGINT) RETURNS BIGINT
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LANGUAGE python
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AS 'def f(x): return x * 2'
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WITH (pip = 'numpy==1.26.4', python_version = '3.11')
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```
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The body is Python source. Its dependencies are declared with it and are part
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of the **immutable function version** -- changing one produces a new version
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rather than altering the registered one, so a column filled by an earlier
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version is unaffected.
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| Option | |
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| --- | --- |
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| `pip` | pip requirements for the worker environment |
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| `conda` | conda packages instead of pip |
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| `conda_channels` | channels in priority order; requires `conda` |
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| `python_version` | worker Python version, defaulting to yours |
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| `gpu` | `'true'` when every execution needs a GPU |
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**Errors and limits**
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| | |
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| --- | --- |
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| `LANGUAGE` other than `python` | refused |
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| `pip` and `conda` together | refused -- pick one |
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| `conda_channels` without `conda` | refused |
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| `gpu` set to anything but `'true'` | refused |
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| An empty body | refused |
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| Any other option | refused, and the message lists what is supported |
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<Note>
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**Enterprise job type:** `create_function`. Registration returns a job because
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the function is baked into an image before the version becomes usable.
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</Note>
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## SHOW FUNCTIONS {#show}
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```sql
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SHOW FUNCTIONS
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```
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Lists registered functions and their versions. Since a version is immutable
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and a column pins the version that fills it, this is how you find which
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versions are still in use before dropping one.
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## DROP FUNCTION {#drop}
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```sql
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DROP FUNCTION embed WITH (version = '1')
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DROP FUNCTION IF EXISTS embed WITH (version = '1')
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DROP FUNCTION embed WITH (version = '1', cascade = 'true')
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```
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`version` is required -- a function is a set of immutable versions, and
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dropping is always of one specific version, never "the function" as a whole.
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<Warning>
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Without `cascade = 'true'`, dropping a version that a column still pins fails
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rather than breaking that column silently. Passing it drops the version and
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lets columns pinned to it stop refreshing -- they keep their last-filled
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values, per [Guarantees](/basics/guarantees#jobs).
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</Warning>
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## What to read next {#next}
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<CardGroup cols={2}>
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<Card title="Function" icon="function" href="/management/function">
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Registering one from the SDK, and diagnosing environment mismatches.
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</Card>
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<Card title="Computed columns" icon="table-columns" href="/feature-engineering/add-computed-column">
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Filling a column with a function instead of an expression.
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</Card>
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</CardGroup>
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