Postgres and Open Source Experts

In PostgreSQL, the EXTRACT() and DATE_PART() functions are used to extract a DOW(an acronym for Day of Week) from a date or timestamp.

In Postgres, a built-in function named TO_CHAR() is used to convert any data type, such as an integer, interval, timestamp, date, etc., to a string.

The CURRENT_TIME function retrieve the current time and the time zone. It can accept an optional parameter “precision” to set the precision of the retrieved fractional seconds.

In Postgres, a new table can be created via the SELECT command; for this, the CREATE TABLE statement is used along with an AS clause followed by a SELECT statement.

PostgreSQL provides a built-in ARRAY_PREPEND() function that is used to append an element at the start of an array. It accepts two arguments: an element and an array.

In Postgres, the UNION ALL operator combines the result sets of two or more queries into one table, including the duplicate records.

In Postgres, the ARRAY_LENGTH() is used to find the array's length. The ARRAY_LENGTH() function finds the array’s length based on the requested dimension.

If a VIEW to be dropped doesn’t exist, then Postgres throws a VIEW doesn’t exist error. To rectify this error, the “IF EXISTS” option is used with the DROP VIEW statement.

Postgres provides the “CREATE VIEW”, “CREATE OR REPLACE VIEW”, and “DROP VIEW” statements to create, update or drop a view from the database.

The POWER() or POW() function accepts two numeric values as arguments and retrieves the first value raised to the power of the second value.