--- title: "bin" slug: "dev-database-reference-sql-functions-string-bin" updated: 2026-10-30T18:18:56Z published: 2026-10-30T18:18:56Z canonical: "docs.vastdata.com/dev-database-reference-sql-functions-string-bin" --- > ## 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. # bin *Applies to VAST Cluster 5.5.* *[Functions](/develop/docs/dev-database-reference-sql-functions-index) › [Binary, hash and UUID functions](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid) › Binary text.* Returns the bits of a value as a string of `0`s and `1`s: for a string, eight digits for each byte of its UTF-8 encoding; for an integer, its value in base 2. `to_binary` is the same function. To read the digits back into bytes, use [from_binary](/develop/docs/dev-database-reference-sql-functions-string-from-binary). ## Syntax ``` bin(s) bin(n) to_binary(s) to_binary(n) ``` | Argument | Type | Description | | --- | --- | --- | | `s` | `VARCHAR` | The string whose bytes to write. | | `n` | `BIGINT`, `UBIGINT`, `HUGEINT` or `VARINT` (smaller integers are cast) | The integer to write in base 2. | **Returns:** `VARCHAR`. **Aliases:** `to_binary`. ## 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_string_bin`. 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 words and numbers. 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_string_bin"' 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, "") 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}.words" run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}") run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, word VARCHAR, n BIGINT)") run(f"INSERT INTO {TABLE} VALUES " "(1, 'a', 5), " "(2, 'hi', 97), " "(3, '', -1), " "(4, 'caf\u00e9', 255), " "(5, NULL, NULL)") ``` ``` [] [] [(5,)] ``` ## What it does `bin` has two forms, chosen by the argument's type: | Argument | What it writes | Example | Result | | --- | --- | --- | --- | | `VARCHAR` | Eight digits for each byte of the UTF-8 encoding, most significant bit first | `bin('a')` | `01100001` | | Integer | The value in base 2, with no leading zeros | `bin(5)` | `101` | A string is written byte by byte, so a character outside ASCII takes 16, 24 or 32 digits: `é` is two bytes in UTF-8, an emoji four. A negative integer is written as its 64-bit two's complement: `bin(-1)` is sixty-four `1`s. The string `'5'` and the number `5` give different results: `bin('5')` writes the byte of the character `5` (`00110101`). ## NULLs and edge cases | Input | Result | | --- | --- | | `NULL` | `NULL` | | `''` (empty string) | `''` | | `'ab'` | 16 digits: `0110000101100010` | | `'é'` | 16 digits (two bytes) | | `'e\u0301'` (e and a combining accent) | 24 digits (three bytes) | | `'5'` and `5` | `00110101` and `101` | | `-1` | Sixty-four `1`s | | A `BLOB`, `DATE`, `BOOLEAN`, `DECIMAL` or list | Error: `No function matches the given name and argument types`, for example `'bin(BLOB)'` | 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-string-bin#set-up-the-examples): ``` run("SELECT bin(NULL), bin(''), bin('ab'), bin('\u00e9'), bin('e\u0301'), bin('5'), bin(5), bin(-1)") run("SELECT to_binary('a'), to_binary(5), length(bin('abc'))") run("SELECT bin('\\xAA'::BLOB)") run("SELECT bin(1.5)") ``` ``` [(None, '', '0110000101100010', '1100001110101001', '011001011100110010000001', '00110101', '101', '1111111111111111111111111111111111111111111111111111111111111111')] [('01100001', '101', 24)] InternalError: Binder Error: No function matches the given name and argument types 'bin(BLOB)'. You might need to add explicit type casts. InternalError: Binder Error: No function matches the given name and argument types 'bin(DECIMAL(2,1))'. You might need to add explicit type casts. ``` ## Examples Each word's bytes, and the number of digits. `café` has 4 characters and 5 bytes, so 40 digits: ``` run(f"SELECT id, word, bin(word), length(bin(word)) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, 'a', '01100001', 8), (2, 'hi', '0110100001101001', 16), (3, '', '', 0), (4, 'café', '0110001101100001011001101100001110101001', 40), (5, None, None, None)] ``` Each number in base 2: ``` run(f"SELECT id, n, bin(n) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, 5, '101'), (2, 97, '1100001'), (3, -1, '1111111111111111111111111111111111111111111111111111111111111111'), (4, 255, '11111111'), (5, None, None)] ``` Write the bytes and read them back: [from_binary](/develop/docs/dev-database-reference-sql-functions-string-from-binary) returns a `BLOB`, and [decode](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid-decode) turns it back into a `VARCHAR`: ``` run(f"SELECT id, from_binary(bin(word)), decode(from_binary(bin(word))) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, b'a', 'a'), (2, b'hi', 'hi'), (3, b'', ''), (4, b'caf\xc3\xa9', 'café'), (5, None, None)] ``` Keep the words that take more than two bytes: ``` run(f"SELECT id, word FROM {TABLE} WHERE length(bin(word)) > 16 ORDER BY id LIMIT 10") ``` ``` [(4, 'café')] ``` ## 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`). `bin()` is a function of a column, so it's computed by the Query Engine: - **In the `SELECT` list,** the scan reads the column and the Query Engine computes `bin()` for each row it returns. - **In `WHERE`,** the scan sends the column for every row, and a `FILTER` step in the Query Engine computes `bin()` and keeps the rows that match. The plan of the `WHERE` example shows the `FILTER` step above the scan: ``` plan(f"SELECT id FROM {TABLE} WHERE length(bin(word)) > 16") ``` ``` ┌───────────────────────────┐ │ PROJECTION │ │ ──────────────────── │ │ #1 │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ FILTER │ │ ──────────────────── │ │ (length(bin(word)) > 16) │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ │ │ Projections: │ │ word │ │ id │ │ │ └───────────────────────────┘ ``` ## Make it faster - **Count bytes with [strlen](/develop/docs/dev-database-reference-sql-functions-string-strlen), not `length(bin(s))`.** `strlen(s) > 2` keeps the same rows as `length(bin(s)) > 16` without building a string eight times the size. - **Compare the raw column when you can.** A comparison of a column with a constant can be evaluated in VAST DataBase; a condition on `bin(column)` is always a `FILTER` step. See [pushdowns](/develop/docs/dev-database-reference-pushdowns). ## Limitations and errors - **No `BLOB`.** `bin('\xAA'::BLOB)` fails with `No function matches the given name and argument types 'bin(BLOB)'`. To see a `BLOB`'s bytes, use [hex](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid-hex), or [decode](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid-decode) it to `VARCHAR` first if it holds UTF-8 text. - **No dates, booleans, decimals or lists.** They fail with the same error. Cast a decimal to an integer type, or a date to `VARCHAR`, first. The error lists the types `bin` accepts. ## Similar functions | Function | Writes | Result for `'a'` | Result for `97` | | --- | --- | --- | --- | | `bin`, `to_binary` | Bytes or value in base 2 | `01100001` | `1100001` | | [hex](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid-hex) | Bytes in base 16 | `61` | (not run here) | | [to_base](/develop/docs/dev-database-reference-sql-functions-numeric-to-base) | An integer in a base from 2 to 36 | (integers only) | `1100001` with `to_base(97, 2)` | | [from_binary](/develop/docs/dev-database-reference-sql-functions-string-from-binary), `unbin` | The reverse: digits to a `BLOB` | `from_binary('01100001')` is `b'a'` | | | [from_hex](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid-from-hex) | The reverse of `hex` | `from_hex('61')` is `b'a'` | | ``` run("SELECT bin('a'), to_binary('a'), hex('a'), from_binary('01100001'), unbin('01100001'), " "from_hex('61'), bin(97), to_base(97, 2)") ``` ``` [('01100001', '01100001', '61', b'a', b'a', b'a', '1100001', '1100001')] ``` Clean up: ``` run(f"DROP TABLE IF EXISTS {TABLE}") run(f"DROP SCHEMA IF EXISTS {SCHEMA}") conn.close() ``` ``` [] [] ``` ## See also - [Binary, hash and UUID functions](/develop/docs/dev-database-reference-sql-functions-binary-hash-uuid): all the binary and encoding functions. - [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.