# 02000 — no_data

> PostgreSQL SQLSTATE 02000 is a no-data condition; PostgreSQL 18.6 has DEBUG diagnostics in amcheck, not a rule that every zero-row SELECT raises it.
---

# 02000 — no_data

## At a glance {#at-a-glance}

`02000` has confirmed 18.6 `DEBUG1`/`DEBUG2` paths in `contrib/amcheck/verify_nbtree.c` for internal index-check conditions. The three groups detailed below are each `DEBUG1`; they are not the same as a normal query returning zero rows and are not a generic client error.

<!-- BEGIN SQLSTATE FACTS: generated by scripts/generate.py; do not edit -->

| Field | Value |
| --- | --- |
| SQLSTATE | `02000` |
| Condition | `no_data` |
| Status | `active` |
| Known present by | `7.4` |
| Locked snapshots | `9.0.23, 9.1.24, 9.2.24, 9.3.25, 9.4.26, 9.5.25, 9.6.24, 10.23, 11.22, 12.22, 13.23, 14.24, 15.19, 16.15, 17.11, 18.6, 19beta3` |
| Macros | `ERRCODE_NO_DATA` |
| Aliases | `—` |

<!-- source facts: data/errcodes/02000.json -->
<!-- END SQLSTATE FACTS -->

## Meaning {#meaning}

The confirmed 18.6 implementation is in `contrib/amcheck/verify_nbtree.c`, where index consistency diagnostics use `ERRCODE_NO_DATA` at `DEBUG1` or `DEBUG2`. This is an internal diagnostic use, not ordinary `SELECT` no-row semantics. The authored evidence expands three representative groups; other source paths are outside that selected message set.

## Messages and diagnostics {#messages}

The selected fixed groups are:

- `DEBUG1`, internal `errmsg_internal`: `harmless fast root mismatch in index "%s"`, with internal detail `Fast root block %u (level %u) differs from true root block %u (level %u).` The source labels this condition harmless.
- `DEBUG1`, internal `errmsg_internal`: `block %u of index "%s" concurrently deleted`. This branch has no detail or hint in the resolved group.
- `DEBUG1`, ordinary `errmsg`/`errdetail`/`errhint`: `index uniqueness can not be checked for index tid=(%u,%u) in index "%s"`, with detail `It doesn't have visible heap tids and key is equal to the tid=(%u,%u)%s (points to heap tid=(%u,%u)).` and hint `VACUUM the table and repeat the check.` The VACUUM hint belongs to this group only.

## Diagnosis {#diagnosis}

If this code comes from amcheck, identify the check, index, block/TID context and server log severity. Treat a fast-root mismatch as the source labels it: a harmless diagnostic requiring context, not automatic corruption repair. For a concurrently deleted block, correlate the concurrent operation or snapshot and rerun only after the relevant activity has settled. For the uniqueness-uncheckable group, inspect the named index and follow its specific VACUUM hint before repeating the check. For application no-row handling, inspect the command result or procedural condition actually returned; PL/pgSQL `NO_DATA_FOUND` is `P0002`, not a blanket synonym for `02000`.

## Response {#response}

Apply the branch-specific guidance: do not turn the harmless fast-root diagnostic into an automatic repair; investigate concurrent state for a concurrent deletion; and use `VACUUM` before repeating the check only when the uniqueness-uncheckable group supplies that hint. Do not require maintenance for every `DEBUG` finding, and do not add a no-row exception or retry to ordinary `SELECT` code solely because the SQLSTATE class is 02.

## Versions {#versions}

`02000` is present from the locked 9.0.23 snapshot through 18.6 and 19 Beta 3, with `known_present_by` 7.4. The fixed 18.6 evidence covers the amcheck DEBUG paths; other producers need separate source evidence.

## Related {#related}

[`P0002`](../p0002/) is PL/pgSQL `no_data_found`; [`02001`](../02001/) concerns additional dynamic result sets; [`00000`](../00000/) is successful completion.

## Sources {#sources}

- [`errcodes.txt`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt#L96) — definition, SHA-256 `6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba`.
- [`verify_nbtree.c`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/contrib/amcheck/verify_nbtree.c#L992-L1001) — fixed path, SHA-256 `a59ae7540a990e5a70e8eb9cedbcad7c62e3e86b1ad426142c8931ee188b752d`.
- [Structured evidence](../data/evidence/02000.json) — fixed sources, message groups, and runtime boundary.