Postgres and Open Source Experts

In PostgreSQL, various inbuilt functions like DATE_PART(), EXTRACT(), and DATE_TRUNC() are used with the GROUP BY clause to group the table’s data by a specific date field.

In PostgreSQL, the DELETE RETURNING clause not only deletes the selected rows but also retrieves the deleted rows.

To create a sequence in Postgres, execute the CREATE SEQUENCE command followed by the name of the sequence to be created.

To make the conditional selection in PostgreSQL, the CASE expression must be used within the SELECT statement.

The “-” operator, DATE_PART(), EXTRACT(), and AGE() functions can be used in PostgreSQL to calculate the difference between various DateTime values.

In Ubuntu, “/etc/init.d/postgresql” and the “systemctl” commands are used with the “start” or “stop” option to activate or deactivate the Postgres server, respectively.

In PostgreSQL, a composite primary key can be defined as a combination of two or more columns that guarantees the uniqueness of a record.

In PostgreSQL, the “psql command not found” error arises if Postgres is not installed or the path for Postgres tools is not set on your system.

In PostgreSQL, the pg_sleep() function accepts the fractional seconds as arguments and delays the execution until the specified seconds pass

In PostgreSQL, the TRIM_ARRAY() function trimmed the specified number of elements from the end of the given array and return a newly updated array.