--- title: "parse_dirpath" slug: "dev-database-reference-sql-functions-string-parse-dirpath" updated: 2026-10-30T18:18:56Z published: 2026-10-30T18:18:56Z canonical: "docs.vastdata.com/dev-database-reference-sql-functions-string-parse-dirpath" --- > ## 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. # parse_dirpath *Applies to VAST Cluster 5.5.* *[Functions](/develop/docs/dev-database-reference-sql-functions-index) › [Text basics](/develop/docs/dev-database-reference-sql-functions-string-text-basics) › Paths.* Returns the directory part of a file path: everything before its last separator. It has no aliases. ## Syntax ``` parse_dirpath(path) parse_dirpath(path, separator) ``` | Argument | Type | Description | | --- | --- | --- | | `path` | `VARCHAR` | The path to read. | | `separator` | `VARCHAR` | Optional. Which character separates components, as for [parse_path](/develop/docs/dev-database-reference-sql-functions-string-parse-path#what-it-does): `'forward_slash'`, `'backslash'`, `'both_slash'` or `'system'` (which means `/` on the cluster). Without it, with `NULL` or with any other value, `/` and `\` both separate components. | **Returns:** `VARCHAR`. **Aliases:** none. ## 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_parse_dirpath`. 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 five file paths, with the directory part stored next to each path. One path is a Windows path and one ends with a separator; 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_parse_dirpath"' 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}.files" run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}") run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, path VARCHAR, folder VARCHAR)") run(f"INSERT INTO {TABLE} VALUES " "(1, '/data/logs/app.log', '/data/logs'), " "(2, '/home/ada/projects/notes.tar.gz', '/home/ada/projects'), " "(3, 'C:\\Users\\jose\\poems.docx', 'C:\\Users\\jose'), " "(4, 'exports/2026/', 'exports/2026'), " "(5, NULL, NULL)") ``` ``` [] [] [(5,)] ``` ## What it does `parse_dirpath` cuts the path at its last separator and returns what comes before it, with the separators as they were written. A path with no separator is a file name alone and gives an empty string: | Path | Result | | --- | --- | | `'/data/logs/app.log'` | `'/data/logs'` | | `'a/b/c.txt'` | `'a/b'` | | `'C:\dir\file.tar.gz'` | `'C:\dir'` | | `'/a//b/c'` | `'/a//b'`: the doubled separator is kept as written. | | `'a/b/'` | `'a/b'`: the last separator is the trailing one, and nothing comes after it. | | `'/c.txt'` | `''`: the root `/` isn't returned. | | `'/'` | `'/'` | | `'c.txt'` | `''` | | `''` | `''` | The part after the last separator is what [parse_filename](/develop/docs/dev-database-reference-sql-functions-string-parse-filename) returns, so for `'a/b/'` that's `''`. To get only the top-level directory, `'/'` for `'/data/logs/app.log'`, use [parse_dirname](/develop/docs/dev-database-reference-sql-functions-string-parse-dirname). **The separator argument.** With `'backslash'`, only `\` separates components: `parse_dirpath('a\b\c', 'backslash')` returns `'a\b'`. With `'forward_slash'`, or `'system'` (which means `/` on the cluster), only `/` does: `parse_dirpath('a/b\c', 'forward_slash')` returns `'a'`. The default, `'both_slash'` and a value that isn't a mode name (`'x'`) cut at the last `/` or `\`: `parse_dirpath('a/b\c')` returns `'a/b'`. A `NULL` separator doesn't make the result `NULL`: `parse_dirpath('a/b', NULL)` returns `'a'`. In Python code, write each `\` of a path as `\\` inside the string, so that the SQL receives one backslash. Python prints each backslash in the results doubled: `'C:\\dir'` is the string `C:\dir`. ## NULLs and edge cases | Input | Result | | --- | --- | | `NULL` | `NULL` | | `''` (empty string) | `''` | | `'c.txt'` (no directory) | `''` | | `'/c.txt'` (a file in the root) | `''` | | `'a/b/'` (trailing separator) | `'a/b'` | | `'a\b\c'` with separator `'backslash'` | `'a\b'` | | `'a/b'` with separator `NULL` | `'a'` | | `'a/b\c'` with no separator, `'both_slash'` or `'x'` | `'a/b'` | | `'a/b\c'` with `'forward_slash'` or `'system'` | `'a'` | | A number, decimal, date, boolean, `BLOB` or list | Error: `No function matches the given name and argument types` | The same cases, as the cluster returns them. The third line runs the other separator modes on a path with both separators. They use the table and helpers from [Set up the examples](/develop/docs/dev-database-reference-sql-functions-string-parse-dirpath#set-up-the-examples): ``` run("SELECT parse_dirpath(NULL), parse_dirpath(''), parse_dirpath('c.txt'), parse_dirpath('/c.txt'), parse_dirpath('a/b/')") run("SELECT parse_dirpath('a\\b\\c', 'backslash'), parse_dirpath('a/b', NULL)") run("SELECT parse_dirpath('a/b\\c'), parse_dirpath('a/b\\c', 'forward_slash'), parse_dirpath('a/b\\c', 'both_slash'), " "parse_dirpath('a/b\\c', 'system'), parse_dirpath('a/b\\c', 'x')") run("SELECT parse_dirpath(123)") ``` ``` [(None, '', '', '', 'a/b')] [('a\\b', 'a')] [('a/b', 'a', 'a/b', 'a', 'a/b')] InternalError: Binder Error: No function matches the given name and argument types 'parse_dirpath(INTEGER_LITERAL)'. You might need to add explicit type casts. ``` ## Examples The directory part of each path, and the file name that follows it: ``` run(f"SELECT id, parse_dirpath(path), parse_filename(path) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, '/data/logs', 'app.log'), (2, '/home/ada/projects', 'notes.tar.gz'), (3, 'C:\\Users\\jose', 'poems.docx'), (4, 'exports/2026', ''), (5, None, None)] ``` Counting the files in each directory needs `GROUP BY`, which the Query Engine doesn't run in VAST Cluster 5.5: the statement fails before any data is read. Group in Trino or Spark, or read the two columns and group them in your application (see [What isn't supported](/develop/docs/dev-database-reference-sql-not-supported)). To count the files in one directory, filter with `WHERE parse_dirpath(path) = '…'` and use `count(*)` without `GROUP BY`. The grouped query returns this error: ``` run(f"SELECT parse_dirpath(path) AS dir, count(*) FROM {TABLE} WHERE path IS NOT NULL " "GROUP BY dir ORDER BY dir LIMIT 10") ``` ``` InternalError: The operator 'HASH_GROUP_BY' type=9 is currently not supported. ``` Keep only the files in one directory: ``` run(f"SELECT id, path FROM {TABLE} WHERE parse_dirpath(path) = '/data/logs' ORDER BY id LIMIT 10") ``` ``` [(1, '/data/logs/app.log')] ``` ## 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 `parse_dirpath()` is always computed by the Query Engine: - **In the `SELECT` list,** the scan reads the column and the Query Engine computes `parse_dirpath()` for each row it returns. - **In `WHERE`,** the scan sends the column for every row, and a `FILTER` step in the Query Engine computes `parse_dirpath()` 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 parse_dirpath(path) = '/data/logs'") ``` ``` ┌───────────────────────────┐ │ PROJECTION │ │ ──────────────────── │ │ #1 │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ FILTER │ │ ──────────────────── │ │ (parse_dirpath(path) = ' │ │ /data/logs') │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ │ │ Projections: │ │ path │ │ id │ │ │ └───────────────────────────┘ ``` ## Make it faster - **Store the directory if you filter on it often.** Compute it when you write the rows and keep it in its own column. A comparison of a raw column with a constant is pushed down to VAST DataBase, so rows that don't match never leave storage. The plan for `folder = '/data/logs'` has no `FILTER` step: ``` plan(f"SELECT id FROM {TABLE} WHERE folder = '/data/logs'") ``` ``` ┌───────────────────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ Projections: id │ │ │ └───────────────────────────┘ ``` - **A pattern on the raw path doesn't help.** `path LIKE '/data/logs/%'` isn't pushed down either: its plan has a `FILTER` step too. Store the directory instead. ``` plan(f"SELECT id FROM {TABLE} WHERE path LIKE '/data/logs/%'") ``` ``` ┌───────────────────────────┐ │ PROJECTION │ │ ──────────────────── │ │ #1 │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ FILTER │ │ ──────────────────── │ │prefix(path, '/data/logs/')│ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ │ │ Projections: │ │ path │ │ id │ │ │ └───────────────────────────┘ ``` - **Combine it with a pushed-down condition.** In `id > 100 AND parse_dirpath(path) = '/data/logs'`, `id > 100` is still evaluated in VAST DataBase, so `parse_dirpath()` runs only on the rows that pass it. ## Limitations and errors - **Strings only.** A number, a decimal, a date, a boolean, a `BLOB` or a list fails with `No function matches the given name and argument types`. - **No root for a file in the root.** `parse_dirpath('/c.txt')` returns `''`, the same as for a file name with no directory. Use [parse_dirname](/develop/docs/dev-database-reference-sql-functions-string-parse-dirname) (`'/'` for an absolute path) to tell them apart. - **A trailing separator is the last separator.** `parse_dirpath('a/b/')` returns `'a/b'`, not `'a'`. ``` run("SELECT parse_dirpath('\\xAA'::BLOB)") run("SELECT parse_dirpath(['a', 'b'])") ``` ``` InternalError: Binder Error: No function matches the given name and argument types 'parse_dirpath(BLOB)'. You might need to add explicit type casts. InternalError: Binder Error: No function matches the given name and argument types 'parse_dirpath(VARCHAR[])'. You might need to add explicit type casts. ``` ## Similar functions | Function | Returns | Result for `'/home/ada/notes.txt'` | Result for `'C:\dir\file.tar.gz'` | | --- | --- | --- | --- | | `parse_dirpath` | the path without its last component | `'/home/ada'` | `'C:\dir'` | | [parse_dirname](/develop/docs/dev-database-reference-sql-functions-string-parse-dirname) | the top-level directory | `'/'` | `'C:'` | | [parse_filename](/develop/docs/dev-database-reference-sql-functions-string-parse-filename) | the last component | `'notes.txt'` | `'file.tar.gz'` | | [parse_path](/develop/docs/dev-database-reference-sql-functions-string-parse-path) | every component, as a list | `['/', 'home', 'ada', 'notes.txt']` | `['C:', 'dir', 'file.tar.gz']` | ``` run("SELECT parse_dirpath('/home/ada/notes.txt'), parse_dirname('/home/ada/notes.txt'), " "parse_filename('/home/ada/notes.txt'), parse_path('/home/ada/notes.txt')") run("SELECT parse_dirpath('C:\\dir\\file.tar.gz'), parse_dirname('C:\\dir\\file.tar.gz'), " "parse_filename('C:\\dir\\file.tar.gz'), parse_path('C:\\dir\\file.tar.gz')") ``` ``` [('/home/ada', '/', 'notes.txt', ['/', 'home', 'ada', 'notes.txt'])] [('C:\\dir', 'C:', 'file.tar.gz', ['C:', 'dir', 'file.tar.gz'])] ``` Clean up: ``` run(f"DROP TABLE IF EXISTS {TABLE}") run(f"DROP SCHEMA IF EXISTS {SCHEMA}") conn.close() ``` ``` [] [] ``` ## See also - [Text basics](/develop/docs/dev-database-reference-sql-functions-string-text-basics): all the text functions. - [parse_path](/develop/docs/dev-database-reference-sql-functions-string-parse-path): the separator modes in detail. - [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.