---
title: "floor"
slug: "dev-database-reference-sql-functions-numeric-floor"
updated: 2026-10-30T18:18:51Z
published: 2026-10-30T18:18:51Z
canonical: "docs.vastdata.com/dev-database-reference-sql-functions-numeric-floor"
---

> ## 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.

# floor

*Applies to VAST Cluster 5.5.*

*[Functions](/develop/docs/dev-database-reference-sql-functions-index) › [Numeric and math functions](/develop/docs/dev-database-reference-sql-functions-numeric) › Sign and rounding.* Rounds a number down, towards negative infinity, to the nearest integer value.

## Syntax

```
floor(x)
```

| Argument | Type | Description |
| --- | --- | --- |
| `x` | `DECIMAL`, `FLOAT` or `DOUBLE`; an integer is converted to `DOUBLE` | The value to round down. |

**Returns:** `DECIMAL(p, 0)` for a `DECIMAL(p, s)`, `FLOAT` for a `FLOAT`, and `DOUBLE` for a `DOUBLE` or an integer.

## Set up the examples

The examples connect with the ADBC driver, as in [VAST Query Engine (ADBC)](/develop/docs/dev-database-integrations-adbc), and work in a schema called `docs_sql_fn_numeric_floor`. Set `QE_ENDPOINT`, `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY` and `VASTDB_BUCKET` ([SQL reference](/develop/docs/dev-database-reference-sql-index#example-connect-and-use-a-transaction)), and run the blocks in order in one Python session. Below each block is the output you should see.

This block connects, defines the `run()` and `plan()` helpers, and creates a table of four measurements: a reading (`DOUBLE`), a price (`DECIMAL`) and a count (`BIGINT`). Row 3 holds a count above 2^53, and the last row has no values:

```
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_fn_numeric_floor"'

conn = 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=True,
)

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)

def plan(sql):
    """Print the plan without its ~N Rows lines: the table's row count, which can still be 0 just after an insert."""
    with conn.cursor() as cur:
        cur.execute("EXPLAIN " + sql)
        steps = cur.fetchall()[0][1]
    print("\n".join(line for line in steps.splitlines() if "Rows" not in line))

TABLE = f"{SCHEMA}.measurements"
run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}")
run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, x DOUBLE, price DECIMAL(10, 2), n BIGINT)")
run(f"INSERT INTO {TABLE} VALUES "
    "(1, 2.5, 2.45, 12), "
    "(2, -1.25, -1.35, -18), "
    "(3, -0.5, 99999999.99, 9007199254740993), "
    "(4, NULL, NULL, NULL)")
```

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

## What it does

`floor(x)` returns the largest integer value that is less than or equal to `x`. Any fraction rounds down: `floor(2.5)` is 2, and a negative value moves away from zero, so `floor(-2.5)` is `-3` and `floor(-0.5)` is `-1`.

The result keeps the kind of number you pass in:

- **`DECIMAL`:** the result is a `DECIMAL` with the same precision and no decimal places. `floor(2.45)` is the `DECIMAL(3,0)` 2, and `floor(99999999.99::DECIMAL(10,2))` is the `DECIMAL(10,0)` 99999999. A number literal such as `2.5` is a `DECIMAL`.
- **`DOUBLE` and `FLOAT`:** the result has the same type and is a whole number, such as `2.0`. A negative zero stays `-0.0`, and `nan`, `inf` and `-inf` stay as they are.
- **Integers:** there's no integer form of `floor`. An integer is converted to `DOUBLE`, and the result is a `DOUBLE`. Above 2^53 a `DOUBLE` can't hold every integer, so `floor(9007199254740993::BIGINT)` returns `9007199254740992.0`. An integer is already a whole number: leave it as it is, or use [trunc](/develop/docs/dev-database-reference-sql-functions-numeric-trunc), which keeps the integer type.

## NULLs and edge cases

| Input | Result |
| --- | --- |
| `x` is NULL | `NULL` |
| `floor(2.5)`, `floor(-2.5)` | `2`, `-3` (`DECIMAL(2,0)`) |
| `floor(-0.5)`, `floor(-0.5::DOUBLE)` | `-1`, `-1.0` |
| `floor(2.0000001::DOUBLE)` | `2.0` |
| `floor(5e-324::DOUBLE)`, the smallest positive `DOUBLE` | `0.0` |
| `floor(-0.0::DOUBLE)` | `-0.0` |
| `floor(&apos;nan&apos;::DOUBLE)`, `floor(&apos;inf&apos;::DOUBLE)` | `nan`, `inf` |
| `floor(99999999.99::DECIMAL(10,2))` | `99999999`, a `DECIMAL(10,0)` |
| `floor(9007199254740993::BIGINT)` | `9007199254740992.0`, a `DOUBLE` |
| `floor(2.45, 1)`: a number of places | Error: `No function matches the given name and argument types &apos;floor(DECIMAL(3,2), INTEGER_LITERAL)&apos;` |
| A string, even `&apos;12&apos;` | Error: `Could not choose a best candidate function for the function call &quot;floor(STRING_LITERAL)&quot;` |
| A date, boolean, `BLOB`, list or interval | Error: `No function matches the given name and argument types` |

The same cases, as the cluster returns them. They use the table and helpers from [Set up the examples](/develop/docs/dev-database-reference-sql-functions-numeric-floor#set-up-the-examples):

```
run("SELECT floor(NULL), floor(2.5), floor(-2.5), floor(-0.5), floor(-0.5::DOUBLE), typeof(floor(2.5))")
run("SELECT floor(2.0000001::DOUBLE), floor(5e-324::DOUBLE), floor(-0.0::DOUBLE), floor('nan'::DOUBLE), "
    "floor('inf'::DOUBLE)")
run("SELECT floor(99999999.99::DECIMAL(10,2)), typeof(floor(99999999.99::DECIMAL(10,2)))")
run("SELECT floor(9007199254740993::BIGINT), typeof(floor(9007199254740993::BIGINT))")
run("SELECT floor(2.45, 1)")
run("SELECT floor('12')")
```

```
[(None, Decimal('2'), Decimal('-3'), Decimal('-1'), -1.0, 'DECIMAL(2,0)')]
[(2.0, 0.0, -0.0, nan, inf)]
[(Decimal('99999999'), 'DECIMAL(10,0)')]
[(9007199254740992.0, 'DOUBLE')]
InternalError: Binder Error: No function matches the given name and argument types 'floor(DECIMAL(3,2), INTEGER_LITERAL)'. You might need to add explicit type casts.
InternalError: Binder Error: Could not choose a best candidate function for the function call "floor(STRING_LITERAL)". In order to select one, please add explicit type casts.
```

## Examples

Round each column down. The `BIGINT` count comes back as a `DOUBLE`:

```
run(f"SELECT id, floor(x), floor(price), floor(n) FROM {TABLE} ORDER BY id LIMIT 10")
```

```
[(1, 2.0, Decimal('2'), 12.0), (2, -2.0, Decimal('-2'), -18.0), (3, -1.0, Decimal('99999999'), 9007199254740992.0), (4, None, None, None)]
```

Round down to one decimal place. `floor` has no places argument, so scale, round down and scale back; the result is a `DOUBLE`:

```
run(f"SELECT id, x, floor(x * 10) / 10 FROM {TABLE} ORDER BY id LIMIT 10")
```

```
[(1, 2.5, 2.5), (2, -1.25, -1.3), (3, -0.5, -0.5), (4, None, None)]
```

Keep the readings from 2 up to, but not including, 3:

```
run(f"SELECT id, x FROM {TABLE} WHERE floor(x) = 2 ORDER BY id LIMIT 10")
```

```
[(1, 2.5)]
```

## How it runs in VAST

The Query Engine runs on the cluster's CNodes, and a query on a table starts with a scan in VAST DataBase (`VAST_SCAN`). VAST DataBase can evaluate a comparison of a column with a constant, but not a function of a column, so `floor()` is always computed by the Query Engine:

- **In the `SELECT` list,** the scan reads the column and the Query Engine computes `floor()` for each row it returns.
- **In `WHERE`,** the scan sends the column for every row, and a `FILTER` step in the Query Engine computes `floor()` and keeps the rows that match. No rows are skipped in storage.

The plan of the `WHERE` example shows the `FILTER` step above the scan:

```
plan(f"SELECT id FROM {TABLE} WHERE floor(x) = 2")
```

```
┌───────────────────────────┐
│         PROJECTION        │
│    ────────────────────   │
│             #1            │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│           FILTER          │
│    ────────────────────   │
│      (floor(x) = 2.0)     │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│         VAST_SCAN         │
│    ────────────────────   │
│    Function: VAST_SCAN    │
│                           │
│        Projections:       │
│             x             │
│             id            │
│                           │
└───────────────────────────┘
```

## Make it faster

- **Write the condition as a range on the raw column.** `floor(x) = 2` is the same as `x &gt;= 2 AND x &lt; 3`, and that form is pushed down to VAST DataBase, so rows that don't match never leave storage. Its plan has no `FILTER` step:

```
plan(f"SELECT id FROM {TABLE} WHERE x >= 2 AND x < 3")
```

```
┌───────────────────────────┐
│         VAST_SCAN         │
│    ────────────────────   │
│    Function: VAST_SCAN    │
│      Projections: id      │
│                           │
└───────────────────────────┘
```

- **A function of constants is fine.** It's computed once, before the scan: a condition such as `x &gt; round(2.4) + sqrt(0.25)` is still a column compared with a constant, and is pushed down.

## Limitations and errors

- **No number of places.** `floor(x, n)` fails with `No function matches the given name and argument types`. Use `floor(x * 100) / 100` for two places, and so on. On negative values this differs from cutting off the digits: `floor(-2.789 * 100) / 100` is `-2.79`, while `trunc(-2.789 * 100) / 100` is `-2.78`.
- **Integers become `DOUBLE`.** See [What it does](/develop/docs/dev-database-reference-sql-functions-numeric-floor#what-it-does). Large `BIGINT` values can lose precision.
- **Strings aren't converted.** `floor(&apos;12&apos;)` fails with `Could not choose a best candidate function`. Cast the string to a number first.
- **Numbers only.** A date, a boolean, a `BLOB`, a list or an interval fails with `No function matches the given name and argument types`. To round a date or timestamp down, use [date_trunc](/develop/docs/dev-database-reference-sql-functions-date-time-date-trunc).

```
run("SELECT floor(2.71, 1)")
run("SELECT floor(2.789 * 100) / 100, floor(-2.789 * 100) / 100, trunc(-2.789 * 100) / 100")
```

```
InternalError: Binder Error: No function matches the given name and argument types 'floor(DECIMAL(3,2), INTEGER_LITERAL)'. You might need to add explicit type casts.
[(2.78, -2.79, -2.78)]
```

## Similar functions

| Function | Rounds | `2.5` | `-2.5` | `2.45` | `-0.5` |
| --- | --- | --- | --- | --- | --- |
| `floor(x)` | down, towards negative infinity | `2` | `-3` | `2` | `-1` |
| [ceil](/develop/docs/dev-database-reference-sql-functions-numeric-ceil) | up, towards positive infinity | `3` | `-2` | `3` | `0` |
| [trunc](/develop/docs/dev-database-reference-sql-functions-numeric-trunc) | towards zero | `2` | `-2` | `2` | `0` |
| [round](/develop/docs/dev-database-reference-sql-functions-numeric-round) | to the nearest; halves away from zero | `3` | `-3` | `2` | `-1` |
| [round_even](/develop/docs/dev-database-reference-sql-functions-numeric-round-even) | to the nearest; halves to the even digit | `2.0` | `-2.0` | `2.0` | `-0.0` |
| [even](/develop/docs/dev-database-reference-sql-functions-numeric-even) | away from zero, to an even integer | `4.0` | `-4.0` | `4.0` | `-2.0` |

`floor`, `ceil`, `trunc` and `round` return a `DECIMAL` for these `DECIMAL` literals; `round_even` and `even` return a `DOUBLE`:

```
run("SELECT floor(2.5), ceil(2.5), trunc(2.5), round(2.5), round_even(2.5, 0), even(2.5)")
run("SELECT floor(-2.5), ceil(-2.5), trunc(-2.5), round(-2.5), round_even(-2.5, 0), even(-2.5)")
run("SELECT floor(2.45), ceil(2.45), trunc(2.45), round(2.45), round_even(2.45, 0), even(2.45)")
run("SELECT floor(-0.5), ceil(-0.5), trunc(-0.5), round(-0.5), round_even(-0.5, 0), even(-0.5)")
```

```
[(Decimal('2'), Decimal('3'), Decimal('2'), Decimal('3'), 2.0, 4.0)]
[(Decimal('-3'), Decimal('-2'), Decimal('-2'), Decimal('-3'), -2.0, -4.0)]
[(Decimal('2'), Decimal('3'), Decimal('2'), Decimal('2'), 2.0, 4.0)]
[(Decimal('-1'), Decimal('0'), Decimal('0'), Decimal('-1'), -0.0, -2.0)]
```

Clean up:

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

```
[]
[]
```

## See also

- [Numeric and math functions](/develop/docs/dev-database-reference-sql-functions-numeric): all the numeric functions.
- [ceil](/develop/docs/dev-database-reference-sql-functions-numeric-ceil), [trunc](/develop/docs/dev-database-reference-sql-functions-numeric-trunc), [round](/develop/docs/dev-database-reference-sql-functions-numeric-round) and [even](/develop/docs/dev-database-reference-sql-functions-numeric-even).
- [Where filters run](/develop/docs/dev-database-reference-sql-select#where-filters-run) and [pushdowns](/develop/docs/dev-database-reference-pushdowns).
- [EXPLAIN](/develop/docs/dev-database-reference-sql-explain): how to read a plan.