microsecond

Applies to VAST Cluster 5.5.

Functions › Date and time functions › Parts of a date or time. Returns the seconds of a timestamp or time of day, including their fraction, as a whole number of microseconds from 0 to 59999999. On an interval, it returns the seconds within the minute of its time part, in microseconds.

Syntax

microsecond(value)

Returns: BIGINT.

Same as: date_part('microsecond', value) and extract(microsecond FROM value); the part also has the names microseconds, us and usec. See date_part.

Set up the examples

The examples connect with the ADBC driver, as in VAST Query Engine (ADBC), and work in a schema called docs_sql_fn_date_time_microsecond. Set QE_ENDPOINT, AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and VASTDB_BUCKET (SQL reference), 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 events. Each has a date (d), a timestamp (ts), a time of day (t) and a timestamp with nanoseconds (tns). Row 4 has no values, and row 5 is the last moment of 1969:

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_date_time_microsecond"'

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}.events"
run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}")
run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, d DATE, ts TIMESTAMP, t TIME, tns TIMESTAMP_NS)")
run(f"INSERT INTO {TABLE} VALUES "
    "(1, DATE '2026-02-28', TIMESTAMP '2026-02-28 23:15:00', TIME '23:15:00', "
    "CAST('2026-02-28 23:15:00.123456789' AS TIMESTAMP_NS)), "
    "(2, DATE '2026-03-01', TIMESTAMP '2026-03-01 08:30:45.123456', TIME '08:30:45.123456', "
    "CAST('2026-03-01 08:30:45.123456' AS TIMESTAMP_NS)), "
    "(3, DATE '2024-12-30', TIMESTAMP '2024-12-30 12:00:00', TIME '12:00:00', "
    "CAST('2024-12-30 12:00:00' AS TIMESTAMP_NS)), "
    "(4, NULL, NULL, NULL, NULL), "
    "(5, DATE '1969-12-31', TIMESTAMP '1969-12-31 23:59:59.999999', TIME '23:59:59.999999', "
    "CAST('1969-12-31 23:59:59.999999999' AS TIMESTAMP_NS))")

[]
[]
[(5,)]

What it does

microsecond returns the seconds part of a timestamp or time of day including the whole seconds, in microseconds: microsecond(TIMESTAMP '2024-02-29 13:45:30.123456') is 30123456 (30 seconds and 123456 microseconds), not 123456. The result runs from 0 to 59999999.

It works on every timestamp precision. A value with less precision gives trailing zeros: microsecond(TIMESTAMP_MS '2024-02-29 13:45:30.123') is 30123000, and microsecond(TIMESTAMP_S '2024-02-29 13:45:30') is 30000000. On a TIMESTAMP_NS value the nanoseconds are dropped: TIMESTAMP_NS '2024-02-29 13:45:30.123456789' gives 30123456. A DATE has no time, so its microsecond is always 0.

To get only the fraction, take the remainder after dividing by 1000000: microsecond(ts) % 1000000.

On an INTERVAL, microsecond returns the seconds within the minute of its time part, in microseconds:

NULLs and edge cases

The same cases, as the cluster returns them. They use the table and helpers from Set up the examples:

run(f"SELECT id, microsecond(ts), microsecond(t) FROM {TABLE} WHERE id = 4")
run("SELECT microsecond(DATE 'infinity'), microsecond(TIMESTAMP '-infinity'), microsecond(DATE '2026-03-01'), "
    "microsecond(TIME '00:00:59.999999'), microsecond(TIMESTAMP '1969-12-31 23:59:59.999999'), "
    "microsecond(TIMESTAMP_MS '2024-02-29 13:45:30.123'), "
    "microsecond(TIMESTAMP_NS '2024-02-29 13:45:30.123456789'), microsecond(TIMETZ '13:45:30.123456+02:30')")
run("SELECT microsecond(INTERVAL '1 year 2 months 3 days 04:05:06.789'), microsecond(INTERVAL '1.5 seconds'), "
    "microsecond(INTERVAL '25 months 40 days 30 hours'), "
    "microsecond(INTERVAL '-1 year -2 months -3 days -04:05:06.789')")
run("SELECT microsecond(NULL)")
run("SELECT microsecond('13:45:30.123456')")
run("SELECT microsecond(123)")

[(4, None, None)]
[(None, None, 0, 59999999, 59999999, 30123000, 30123456, 30123456)]
[(6789000, 1500000, 0, -6789000)]
InternalError: Binder Error: Could not choose a best candidate function for the function call "microsecond("NULL")". In order to select one, please add explicit type casts.
InternalError: Binder Error: Could not choose a best candidate function for the function call "microsecond(STRING_LITERAL)". In order to select one, please add explicit type casts.
InternalError: Binder Error: No function matches the given name and argument types 'microsecond(INTEGER_LITERAL)'. You might need to add explicit type casts.

Examples

The seconds of each event's timestamp in microseconds, the fraction alone, and the same for the time of day:

run(f"SELECT id, microsecond(ts), microsecond(ts) % 1000000, microsecond(t) FROM {TABLE} ORDER BY id LIMIT 10")

[(1, 0, 0, 0), (2, 45123456, 123456, 45123456), (3, 0, 0, 0), (4, None, None, None), (5, 59999999, 999999, 59999999)]

Keep only the events whose timestamp falls exactly on a second:

run(f"SELECT id FROM {TABLE} WHERE microsecond(ts) % 1000000 = 0 ORDER BY id LIMIT 10")

[(1,), (3,)]

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 microsecond() is always computed by the Query Engine:

• In the SELECT list, the scan reads the column and the Query Engine computes microsecond() for each row it returns.
• In WHERE, the scan sends the column for every row, and a FILTER step in the Query Engine computes microsecond() 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 microsecond(ts) % 1000000 = 0")

┌───────────────────────────┐
│         PROJECTION        │
│    ────────────────────   │
│             #1            │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│           FILTER          │
│    ────────────────────   │
│   (("microsecond"(ts) %   │
│        1000000) = 0)      │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│         VAST_SCAN         │
│    ────────────────────   │
│    Function: VAST_SCAN    │
│                           │
│        Projections:       │
│             ts            │
│             id            │
│                           │
└───────────────────────────┘

Make it faster

• Combine it with a range on the raw column. In ts >= TIMESTAMP '2026-03-01 00:00:00' AND ts < TIMESTAMP '2026-03-02 00:00:00' AND microsecond(ts) % 1000000 = 0, the range is still evaluated in VAST DataBase, so microsecond() runs only on the rows of that day. The plan's FILTER step holds only the microsecond() condition:

plan(f"SELECT id FROM {TABLE} WHERE ts >= TIMESTAMP '2026-03-01 00:00:00' AND ts < TIMESTAMP '2026-03-02 00:00:00' "
     "AND microsecond(ts) % 1000000 = 0")

┌───────────────────────────┐
│         PROJECTION        │
│    ────────────────────   │
│             #1            │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│           FILTER          │
│    ────────────────────   │
│   (("microsecond"(ts) %   │
│        1000000) = 0)      │
│                           │
└─────────────┬─────────────┘
┌─────────────┴─────────────┐
│         VAST_SCAN         │
│    ────────────────────   │
│    Function: VAST_SCAN    │
│                           │
│        Projections:       │
│             ts            │
│             id            │
│                           │
└───────────────────────────┘

• Store the value if you filter on it often. Compute it when you write the rows and keep it in its own column: a comparison of that column with a constant is pushed down, microsecond(ts) % 1000000 = 0 isn't.

Limitations and errors

• No time-zone support for timestamps. On a TIMESTAMP WITH TIME ZONE value, such as now(), microsecond fails with an Extension Autoloading Error. Cast the value to TIMESTAMP first; see time zones. A TIME WITH TIME ZONE value works.
• No nanoseconds. On a TIMESTAMP_NS value, the digits below a microsecond are dropped. Use nanosecond to keep them.
• TIMESTAMP_NS just before 1970. Row 5's tns, 1969-12-31 23:59:59.999999999, gives 0, not 59999999. Store such values as TIMESTAMP, or use nanosecond: row 5's nanosecond(tns) is 59999999999.

run(f"SELECT id, microsecond(tns), microsecond(ts), nanosecond(tns) FROM {TABLE} ORDER BY id LIMIT 10")

[(1, 123456, 0, 123456789), (2, 45123456, 45123456, 45123456000), (3, 0, 0, 0), (4, None, None, None), (5, 0, 59999999, 59999999999)]

Similar functions

run("SELECT microsecond(TIMESTAMP '2024-02-29 13:45:30.123456'), second(TIMESTAMP '2024-02-29 13:45:30.123456'), "
    "millisecond(TIMESTAMP '2024-02-29 13:45:30.123456'), nanosecond(TIMESTAMP '2024-02-29 13:45:30.123456'), "
    "strftime(TIMESTAMP '2024-02-29 13:45:30.123456', '%S.%f')")

[(30123456, 30, 30123, 30123456000, '30.123456')]

Clean up:

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

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See also

• date_part: any part of a value, by name.
• Date and time functions: all the date and time functions.
• Where filters run and pushdowns.
• EXPLAIN: how to read a plan.