Experts in Postgres and Open Source Infrastructure

The “can't insert a non-default value into column id” error arises when a user tries to insert the value to an IDENTITY column that is created using the "GENERATED ALWAYS" option.

To alter the “max_connections” parameter in Postgres, the “ALTER SYSTEM SET max_connections = num_of_connections;” command is used.

In PostgreSQL, “LASTVAL()” is a built-in function that retrieves the most recently generated sequence value of the current session.

In PostgreSQL, the ALTER TABLE statement is used with ADD IDENTITY or DROP IDENTITY to add or remove an IDENTITY column to a Postgres table.

PostgreSQL 10 introduced a new feature named the "IDENTITY" column, which allows us to create a table’s column with auto-incrementing values.

In PostgreSQL, the SUM() function can be executed with the GROUP BY clause to compute the sum of a particular column grouped by single or multiple columns.

To increase maximum connections in PostgreSQL, open the configuration file, locate the “max_connections” variable in that file, and increase its value according to your needs.

Use the sequence option to specify the start value and the increment value for an IDENTITY column in PostgreSQL.

In PostgreSQL, the main difference between the BIGSERIAL, SMALLSERIAL, and SERIAL is the range of numbers they can hold/store.

In PostgreSQL, “CURRVAL()” is a built-in function that returns the most recently retrieved value of the NEXTVAL() function for a specific sequence in the current session.