---
title: "DELETE and TRUNCATE"
slug: "dev-database-reference-sql-delete"
updated: 2026-10-30T18:19:11Z
published: 2026-10-30T18:19:11Z
canonical: "docs.vastdata.com/dev-database-reference-sql-delete"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# DELETE and TRUNCATE

*Applies to VAST Cluster 5.5.*

`DELETE` deletes the rows that match a condition. `TRUNCATE` deletes every row of a table, and keeps the table.

## Syntax

```
DELETE FROM "<bucket>/<schema>".<table> [WHERE <condition>]
TRUNCATE [TABLE] "<bucket>/<schema>".<table>
```

## Parameters and rules

| Part | Meaning |
| --- | --- |
| `WHERE &lt;condition&gt;` | Which rows to delete. Any condition that works in a [SELECT](/develop/docs/dev-database-reference-sql-select) on one table works here. Without `WHERE`, every row is deleted. |
| `TRUNCATE [TABLE]` | Deletes every row. `TRUNCATE TABLE &lt;table&gt;` and `TRUNCATE &lt;table&gt;` both work. |

- Both statements return one row with one column, `Count`: the number of rows deleted.
- To delete rows that match another table, query that table first, and put the values in the `WHERE` clause: a subquery such as `IN (SELECT ...)` needs a join, which isn't supported. Mind the [IN list rule](/develop/docs/dev-database-reference-sql-select#in-lists).
- The Query Engine can't delete from a partitioned table, so it can't drop partitions either. Use the Python SDK, Trino or Spark ([updates and deletes](/develop/docs/dev-database-guides-updates-and-deletes#partitioned-tables)).
- You can't delete through a snapshot path: snapshots are read-only.

## What happens on the cluster

The Query Engine finds the rows that match `WHERE`, following the same [rules](/develop/docs/dev-database-reference-sql-select#where-filters-run) as a `SELECT`, and VAST DataBase marks them as deleted. Only the count comes back. Deleted rows stop being visible when the transaction commits, but their space is freed later, in the background ([write path](/develop/docs/dev-database-concepts-architecture-write-path#deletes)).

## Example

The examples use the `run()` helper and the environment variables described in the [SQL reference](/develop/docs/dev-database-reference-sql-index#example-connect-and-use-a-transaction). This block connects, and creates the schema `docs_sql_delete` with four rows:

```
import os
import re

import adbc_driver_manager
import adbc_driver_manager.dbapi as dbapi
import adbc_driver_vastdb

BUCKET = os.environ["VASTDB_BUCKET"]
SCHEMA = f'"{BUCKET}/docs_sql_delete"'

def connect(autocommit=True):
    return dbapi.connect(
        driver=adbc_driver_vastdb.get_driver_path(),
        db_kwargs={
            "vast.db.endpoint": os.environ["QE_ENDPOINT"],
            "vast.db.access_key": os.environ["AWS_ACCESS_KEY_ID"],
            "vast.db.secret_key": os.environ["AWS_SECRET_ACCESS_KEY"],
        },
        autocommit=autocommit,
    )

def server_message(e):
    """The server's message in a driver error, without the request ID or the echoed statement."""
    text = re.sub(r"\[req=0x[0-9a-f]+\]: ", "", str(e))
    found = (re.search(r'message: "(.*?)", request_id', text, re.S)
             or re.search(r"description: (.*)\)", text, re.S))
    message = found.group(1) if found else text.strip().splitlines()[-1]
    message = re.sub(r"^Plan query: '.*?' failed with: ", "", message, flags=re.S)
    message = re.split(r"\\n|\n", message)[0].replace('\\"', '"')
    return message.replace(BUCKET, "<bucket>")

def run(sql):
    """Run one statement. Print the rows it returns, or the error."""
    try:
        with conn.cursor() as cur:
            cur.execute(sql)
            rows = cur.fetchall() if cur.description else []
    except (adbc_driver_manager.Error, OSError) as e:
        print(f"{type(e).__name__}: {server_message(e)}")
    else:
        print(rows)

conn = connect()
TABLE = f"{SCHEMA}.readings"
run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}")
run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, city VARCHAR, temperature DOUBLE)")
run(f"INSERT INTO {TABLE} VALUES (1, 'Lisbon', 21.5), (2, 'Oslo', 4.0), (3, 'Cairo', 30.2), (4, 'Lima', NULL)")
```

```
[]
[]
[(4,)]
```

Delete with a condition, then empty the table with `TRUNCATE`:

```
run(f"DELETE FROM {TABLE} WHERE temperature < 10 OR temperature IS NULL")
run(f"SELECT id, city FROM {TABLE} ORDER BY id LIMIT 10")
run(f"TRUNCATE TABLE {TABLE}")
run(f"SELECT count(*) FROM {TABLE}")
```

```
[(2,)]
[(1, 'Lisbon'), (3, 'Cairo')]
[(2,)]
[(0,)]
```

Clean up:

```
run(f"DROP TABLE IF EXISTS {TABLE}")
run(f"DROP SCHEMA IF EXISTS {SCHEMA}")
conn.close()
```

```
[]
[]
```

## Errors

No `DELETE` or `TRUNCATE` errors are listed here. For the conditions the Query Engine refuses, such as subqueries and long `IN` lists, see the [SELECT errors](/develop/docs/dev-database-reference-sql-select#errors).

## Trino and Spark

Trino and Spark delete with their own `DELETE` statements, and can also delete whole partitions; see [updates and deletes](/develop/docs/dev-database-guides-updates-and-deletes#update-and-delete-with-trino-spark-or-the-vast-query-engine).

See also: [UPDATE](/develop/docs/dev-database-reference-sql-update), [DROP TABLE](/develop/docs/dev-database-reference-sql-drop-table), [updates and deletes](/develop/docs/dev-database-guides-updates-and-deletes).