In PostgreSQL, the date_part() function retrieves subfields such as the year, month, hour, or minute, part from a date/time value.
It’s equivalent to the extract() function, although with a slightly different syntax.
Tag: dates
How Extract() Works in PostgreSQL
In PostgreSQL, the extract() function retrieves subfields such as the year, month, hour, or minute, part from a date/time value.
It’s equivalent to the date_part() function, although with a slightly different syntax.
How justify_interval() Works in PostgreSQL
In PostgreSQL, the justify_interval() function adjusts an interval using justify_days and justify_hours. It allows you to use additional sign adjustments to adjust the interval.
How justify_days() Works in PostgreSQL
In PostgreSQL, the justify_days() function allows you to adjust an interval value, so that 30-day time periods are represented as months.
For example, if you have an interval of say, 30 days, justify_days() will return it as 1 mon.
How justify_hours() Works in PostgreSQL
In PostgreSQL, the justify_hours() function allows you to adjust an interval value, so that 24-hour time periods are represented as days.
For example, if you have an interval of say, 24 hours justify_hours() will return it as 1 day.
How IsFinite() Works in PostgreSQL
In PostgreSQL, the isfinite() function tests for a finite date, timestamp or interval.
This can be useful, because Postgres supports infinite dates/timestamps. For example, you could have a timestamp of infinity or negative infinity, and this function allows you to test for that.
Continue readingHow pg_typeof() Works in PostgreSQL
In PostgreSQL, the pg_typeof() function allows you to get the data type of any value.
More specifically, it returns the OID of the data type of the value that is passed to it. It returns a regtype, which is an OID alias type. Therefore it’s the same as an OID for comparison purposes but displays as a type name.
How clock_timestamp() Works in PostgreSQL
In PostgreSQL, clock_timestamp() is a non-SQL-standard time function that returns the current date and time.
An important consideration of this function is that its result changes throughout the execution of a statement. Therefore, you could get a different result in different parts of the statement if you call the function multiple times within a single statement.
Continue readingHow pg_sleep() Works in PostgreSQL
In PostgreSQL, you can use the pg_sleep() function to delay execution for a given number of seconds.
It makes the current session’s process sleep until the specified number of seconds have elapsed. It works similar to MySQL‘s sleep() function, and also TSQL‘s waitfor statement in SQL Server.
The pg_sleep() function accepts a double precision argument, so you can also specify fractional-second delays.
The sleep delay will be at least as long as specified. However, it could be longer depending on factors such as server load, as well as your platform’s effective resolution of the sleep interval.
Continue readingHow pg_sleep_for() Works in PostgreSQL
In PostgreSQL, you can use the pg_sleep_for() function to delay execution for a given interval.
It makes the current session’s process sleep until the specified interval has elapsed.
The sleep delay will be at least as long as specified. However, it could be longer depending on factors such as server load, as well as your platform’s effective resolution of the sleep interval.
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