# Reported issues for oraclemcp

Pod holds 16 of 25 GitHub reports that passed its relevance review. This can include external user reports, maintainer-confirmed bugs, and concrete feature gaps. Treat them as evidence to inspect, not a count of distinct defects.

Back to [oraclemcp](/mcp/oraclemcp).

## Most discussed

### oracle_query on policy-heavy schema always times out: per-call RLS/VPD probe (ALL_POLICIES) blows the 30s budget

## Summary

On a policy-heavy schema, **every `oracle_query` is cancelled at the 30s request budget** (`{"error_class":"TIMEOUT","message":"request cancelled: Cancelled"}`) even for a trivial `SELECT 1 FROM dual`. Root cause is the per-call **RLS/VPD visibility probe** (`ALL_POLICIES`) that `oracle_query` attaches to every result: on a schema with many active VPD policies that probe alone exceeds the 30s budget and takes the whole read down with it. The database is healthy and plain SELECTs…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/59) · 2026-09-28 · open · 0 comments

### Connection-failure diagnosability: 'driver detail suppressed', connect trace stops at read ACCEPT, misleading first hint

> Field-test report (error-clarity / diagnosability). Observed on OCI connect attempts during the 0.11.0 adoption; the gap is general to connection failures. Sanitized.

### Summary
When a connection fails (seen on OCI Autonomous DB profiles), the failure is hard to diagnose:
1. The client gets `Oracle connection failed; driver detail suppressed` — the underlying Oracle/driver error is hidden, and there's no documented switch to reveal it.
2. The suggested `ORACLEDB_TRACE_CONNECT=1` trace stops…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/56) · 2026-09-23 · open · 0 comments

### OCI ADB wallet: default musl build rejects stock wallet (cwallet.sso unsupported / ewallet.pem legacy 3DES-PKCS12)

> Field-test report. First observed at v0.7.2 (default musl build); please confirm current status on 0.11.0 (see note). Sanitized.

### Summary
The default **musl** build could not consume a **stock, unmodified OCI Autonomous Database wallet**:
- `cwallet.sso` (the SSO auto-login wallet) was unsupported by the driver's wallet loader.
- `ewallet.pem` / `.p12` private key uses a **legacy 3DES PKCS#12** scheme (PBE OID `1.2.840.113549.1.12.1.3`), which the Rust PKCS12 parser rejected — it accepted…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/55) · 2026-09-23 · open · 0 comments

### OCI Autonomous DB: post-ACCEPT auth/TTC handshake fails in oraclemcp-driver-cx (on-prem 19c + python-oracledb thin both work)

> Field-test report (not a fresh code-traced repro). Observed across install-test rounds up to the 0.11.0 adoption. Sanitized of host/schema/profile names.

### Summary
Against an **OCI Autonomous Database** (mTLS wallet, TCPS EZConnect descriptor), the thin driver `oraclemcp-driver-cx 0.9.2` completes TLS + wallet load (`cwallet.sso`) + TNS **ACCEPT**, but then **fails the post-ACCEPT auth / TTC handshake**. On-prem Oracle 19c connects fine with the same driver, so this is specific to…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/54) · 2026-09-23 · open · 0 comments

### Read-only guard bypass: oracle_sample_rows skips the VPD/purity proof and result-masking

> Read-only guard **bypass**. Reported publicly at the maintainer's direction; see SECURITY.md for the normal private-disclosure path. Confirmed from source at commit 73973b2 (v0.11.0). No database data included.

### Summary
`oracle_sample_rows` reads **VPD/policy-protected tables and views** that `oracle_query` refuses, and returns rows **without applying the profile's result-masking policy**. On a read-only, masking-enforced profile this exposes protected rows and unmasked column values.…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/53) · 2026-09-23 · open · 0 comments

### Read-only guard bypass: view/VPD/policy objects reachable via a subquery (EXISTS/IN)

> Read-only guard **bypass**. Reported publicly at the maintainer's direction; see SECURITY.md for the normal private-disclosure path. Confirmed from source at commit 73973b2 (v0.11.0). No database data included.

### Summary
On a read-only profile, a `SELECT` can reach a **view**, a **VPD/policy-protected table**, or an object with a **virtual-column / policy-function dependency** — all of which `oracle_query` refuses at top level — simply by referencing it inside a subquery (`EXISTS`, `IN`,…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/52) · 2026-09-23 · open · 0 comments

### Second serve instance refuses pre-handshake on audit-log lock; client sees only 'Connection closed'

### Version
0.11.0 (commit 73973b2).

### What happens
Each MCP client session launches its own `oraclemcp serve`. Starting a **second** instance for the same user/host fails: the child exits before the MCP handshake with

```
refusing to start: audit log .../audit/audit.jsonl is locked by another oraclemcp instance (pid N); refusing to fork the hash-chain
```

on **stderr**, exit code 2. The MCP client sees only the process die with nothing on stdout → `CONNECTION_CLOSED` / "Connection…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/51) · 2026-09-23 · open · 0 comments

### 'call timeout of 0 ms exceeded' from head-of-line blocking on the pinned-session mutex

### Version
0.11.0 (commit 73973b2). Driver: `oraclemcp-driver-cx =0.9.2`.

### What happens
While one `oracle_query` is running long, a second `oracle_query` fails **immediately** with `call timeout of 0 ms exceeded`. The "0 ms" is misleading — it is not a zero timeout, it's an already-expired deadline.

### Root cause (confirmed in code)
The second request blocks on `self.state.lock(cx)` behind the long query (`dispatch/mod.rs:12118`; the comment at `:12124` notes the mutex wait counts…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/50) · 2026-09-23 · open · 0 comments

## Most recent

### Long queries emit no progress and notifications/cancelled is ignored (client told cancelled while query succeeds server-side)

### Version
0.11.0 (commit 73973b2).

### What happens
During a long-running `oracle_query`, the client receives **no progress** for the whole duration, and `notifications/cancelled` is **ignored** — the statement is never cancelled server-side. In two observed cases the client was told `{"error_class":"TIMEOUT","message":"request cancelled: Cancelled"}` after ~31s, but the audit log shows the **same query SUCCEEDED** (rows returned) — i.e. the client believes the read was cancelled while it…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/49) · 2026-09-23 · open · 0 comments

### call_timeout_seconds=0 silently disables BOTH per-call and whole-request timeouts; Some(0) mappings disagree

### Version
0.11.0 (commit 73973b2). Driver: `oraclemcp-driver-cx =0.9.2`.

### What happens
Setting a profile's `call_timeout_seconds = 0` — the natural way to say "no per-round-trip limit" — silently **also removes the whole-request timeout**, so a query can run unbounded (observed: a query ran >30 minutes until the MCP client aborted it). The three timeout mappings also disagree on what `Some(0)` means.

### Root cause (confirmed in code)
`call_timeout_seconds = 0` maps to `None` in two…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/48) · 2026-09-23 · open · 0 comments

### Pinned session never recovers after idle: protocol-desync errors not classified as connection-lost + no keepalive default

### Version
0.11.0 (commit 73973b2). Driver: `oraclemcp-driver-cx =0.9.2`.

### What happens
After the pinned stdio session sits idle (minutes to a couple of hours), the next tool call fails, and **keeps failing on every retry**, with one of:
- `query: unknown TTC message type 84 at position 0` (`CONNECTION_FAILED`)
- `Oracle returned no current system change number`
- `ORA-00904: "DBMS_FLASHBACK"."GET_SYSTEM_CHANGE_NUMBER": invalid identifier`
- `ORA-01555: snapshot too old` on trivial selects…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/47) · 2026-09-23 · open · 0 comments

### SCN capability probe runs on every call and is never cached (32% of audited traffic; fails 142/142 where ungranted)

### Version
0.11.0 (commit 73973b2)

### What happens
The SCN capability probe (`scn_capability_probe`, the internal `DBMS_FLASHBACK.GET_SYSTEM_CHANGE_NUMBER` / current-SCN check) runs **before every tool call** and its result is never cached. In a real two-day audit log it accounted for **142 of 441 entries (32%)** and **failed 142/142** on databases where that capability isn't granted — including on the very first call after startup, so it is not an idle-only symptom.

### Why it matters
1.…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/46) · 2026-09-23 · open · 0 comments

### oracle_describe_view on a nonexistent view returns success with empty data

### Version
0.11.0 (commit 73973b2)

### What happens
`oracle_describe_view` on a view that does not exist returns **success with empty data** instead of an object-not-found error:

```json
{"columns": [], "name": "SOME_MISSING_VIEW", "owner": "SOME_OWNER", "view": null}
```

Observed on three names that were confirmed (via a separate read-only path) not to exist in that schema. A caller can't distinguish "view exists but has no columns" from "view does not exist", and `view: null` is a silent…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/43) · 2026-09-23 · open · 0 comments

### Generated-read guard refusal downgraded to INTERNAL, losing PolicyDenied/ForbiddenStatement class

### Version
0.11.0 (commit 73973b2)

### What happens
When the generated-read guard (used by `oracle_describe`, `oracle_sample_rows`, `oracle_get_source`, etc.) refuses a statement, the refusal reaches the client as a generic `INTERNAL` error instead of the real `PolicyDenied` / `ForbiddenStatement` class and message.

### Root cause (confirmed in code)
`GuardedGeneratedReadConn::before_query` maps a refusal envelope to `DbError::Internal(format!("{:?}: {}", class, msg))` via…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/42) · 2026-09-23 · open · 0 comments

### oracle_get_source rejects VIEW while get_ddl accepts it; object_type is a free string, not an enum

### Version
0.11.0 (commit 73973b2)

### What happens
- `oracle_get_source` does not accept `object_type: "VIEW"` (fails with "unsupported source object type"), while `oracle_get_ddl` does accept VIEW. A client reasonably expects "get source" to work for a view.
- The `object_type` argument is a free-form string in the schema (`crates/oraclemcp/src/registry.rs:1061`), not an enum, so clients can't discover the allowed values up front and only learn of the restriction by failing.

### Root cause…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/39) · 2026-09-23 · open · 0 comments

### Error misclassification: argument errors and ORA-01555 -> CONNECTION_FAILED; server-owned SQL failure -> SYNTAX_ERROR

### Version
0.11.0 (commit 73973b2)

### What happens
Several failures are given the wrong `error_class` and a misleading `suggested_tool`:

1. **Argument errors reported as connection failures.** `oracle_get_source {"object_type": "VIEW"}` →
   `{"error_class":"CONNECTION_FAILED","message":"unsupported source object type: \"VIEW\"","suggested_tool":"oracle_connection_info"}`.
   It's a bad argument, not a connection problem. Same pattern for other validation messages: `search_source`,…

[Read the thread](https://github.com/MuhDur/oraclemcp/issues/38) · 2026-09-23 · open · 0 comments

The remaining reports are on [the project's issue tracker](https://github.com/MuhDur/oraclemcp/issues).