How Random() Works in PostgreSQL

In PostgreSQL, the random() function returns a pseudo-random value in the range 0.0 <= x < 1.0.

It uses a simple linear congruential algorithm, which is one of the oldest and best-known pseudo-random number generator algorithms.

A pseudo-random number is a number that appears to be random, but is not truely random. A pseudo-random number is not truely random because its value was generated by a known seed. However, it will appear to be random if the user has no knowledge of the seed or algorithm that created it.

Therefore, pseudo-random numbers are often considered good enough for many applications.

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How Asin() Works in PostgreSQL

In PostgreSQL, asin() is a mathematical function that returns the angle, in radians, whose sine is the specified expression.

In other words, it returns the arcsine of its argument.

The arcsine is typically used to find the measure of an angle when two sides of a right triangle are known.

The arcsine is the inverse of the sine function. To return the sine in Postgres, use sin() to specify the angle in radians, or sind() to specify it in degrees.

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