Experts in Postgres and Open Source Infrastructure

The transaction_timestamp() function returns the timestamp for the current transaction. This function does not need any argument.

The starts_with() function takes a string and checks whether that string starts with another specified string passed as an argument in the function and returns a boolean.

RAISE NOTICE is used to raise an error and report a message and that error is reported back to the user. It is followed by a format that is basically the string we want to show to the user.

The strpos() is a built-in function in PostgreSQL that is used to determine the position/location of a sub-string in a main string.

The SELECT LIMIT statement is used to limit data up to a specified number of rows. The number of rows has to be specified after the LIMIT keyword.

The array_fill() is a function that fills an array with a specified argument. The dimensions of that array are also specified in that function as an argument.

The make_interval() method generates an interval based on the arguments passed into it. All the arguments are of INT data type except the last one i.e. seconds, which is of DOUBLE PRECISION.

The PostgreSQL translate() function returns a string after replacing a set of strings from one main string with some set of characters specified.

In PostgreSQL, there are two ways to calculate/get the square of a number: the POWER() function and a user-customized logic, i.e., multiplying the number by itself.

The CITEXT data type in PostgreSQL is case-insensitive that allows us to do text comparisons without worrying about the case.