Doc gap [MED]: [GetExecuteQuerySQL] — [influxdb3] [enterprise]

### Severity

🟡 Medium — common feature, affects some users

### Edition scope

Both Core and Enterprise

### Change type

Existing gap (endpoint has been undocumented across releases)

### Operation ID

GetExecuteQuerySQL, GetExecuteQueryInfluxQL

### API path and method

GET /api/v3/query_sql

### Release version

v3.9.0

### Spec claim

The documentation is indeterminate about support for the SQL `DELETE` statement.

### Existing doc coverage

The knowledge sources don't provide direct information about `DELETE` in SQL for InfluxDB 3 Enterprise specifically. However, based on the available sources, here's what is known:

**InfluxQL `DELETE`** is parsed and recognized as a valid statement in the InfluxQL parser, but the query planner explicitly marks it as **not implemented** — meaning it is parsed but returns a "not implemented" error when executed. [[[planner.rs](https://github.com/influxdata/influxdb/blob/main/core/iox_query_influxql/src/plan/planner.rs#L719-L817)](https://github.com/influxdata/influxdb/blob/main/core/iox_query_influxql/src/plan/planner.rs#L719-L817)]

For **InfluxDB 3 Cloud Serverless, Cloud Dedicated, and Clustered**, the `DELETE` command is explicitly listed as **not supported** via InfluxQL. [[[Cloud Serverless](https://docs.influxdata.com/influxdb3/cloud-serverless/guides/api-compatibility/v1/#bucket-management-with-influxql-not-supported)](https://docs.influxdata.com/influxdb3/cloud-serverless/guides/api-compatibility/v1/#bucket-management-with-influxql-not-supported); [[Cloud Dedicated](https://docs.influxdata.com/influxdb3/cloud-dedicated/guides/api-compatibility/v1/#database-management-with-influxql-not-supported)](https://docs.influxdata.com/influxdb3/cloud-dedicated/guides/api-compatibility/v1/#database-management-with-influxql-not-supported)]

The knowledge sources do not contain specific information about SQL `DELETE` support in InfluxDB 3 Enterprise. For authoritative guidance on your specific version, I'd recommend checking the [[InfluxDB 3 Enterprise documentation](https://docs.influxdata.com/influxdb3/enterprise/)](https://docs.influxdata.com/influxdb3/enterprise/) directly or reaching out to InfluxData support.

### Suggested documentation location

- content/shared/influxdb3/sql

### Engineering verification ask

Please confirm before documentation is written:

- [ ] Is this endpoint intended for public use in the identified release version?
- [ ] Does this endpoint replace or extend an existing endpoint? If so, which one?
- [ ] What are the primary use cases for end users?
- [ ] Are there any known limitations, gotchas, or required prerequisites?
- [ ] Is the behavior identical across Core and Enterprise, or are there edition-specific differences?

### Definition of done

- [ ] Engineering confirmed the endpoint is public and stable in the identified release
- [ ] Doc page created or updated at the suggested location
- [ ] API reference entry updated (description, parameters, example request/response)
- [ ] Related guides updated if endpoint behavior changed
- [ ] Tested against the release binary (not just the spec)

### Edition checklist

- [ ] Core behavior documented
- [ ] Enterprise-specific behavior documented (if any differences from Core)
- [ ] Superset relationship noted where applicable (Enterprise includes all Core changes)

Start in content/shared/influxdb3/sql and review the linked core/iox_query_influxql/src/plan/planner.rs context for the DELETE behavior. First obtain engineering confirmation about endpoint stability, edition differences, and release behavior, then update the page and API reference with examples and limitations. Done means the documentation is verified against the release binary and covers Core and Enterprise differences.

Written by the indexing model from the issue text.