BUG #16628: Hostame and string connection functions

On Tue, Sep 22, 2020 at 06:57:13PM +0000, PG Bug reporting form wrote:

The following bug has been logged on the website:

Bug reference: 16628
Logged by: Anderson Antunes
Email address: anderson.ant.oli@gmail.com
PostgreSQL version: 9.5.0
Operating system: Linux
Description:

Hi,

Is there any possibility of developing a function to retrieve hostname and
the connection string?

Example:

select get_host_name ();

You can get the server IP address, but not the host name:

test=> SELECT inet_server_addr();
inet_server_addr
------------------
127.0.0.1

select get_string_connection ();

Uh, the connection information is parsed by libpq, and visible in psql:

test=> \conninfo You are connected to database "test" as user
"postgres" on host "localhost" (address "127.0.0.1")
at port "5432".

but the server only sees the result. You can see the server port
number:

test=> SELECT inet_server_port();
inet_server_port
------------------
5432

I can't figure out how to query the SSL mode via SQL. Does this help?

--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EnterpriseDB https://enterprisedb.com

The usefulness of a cup is in its emptiness, Bruce Lee

I'm sorry for not responding earlier. She ended up falling into spam. I
solved it by creating a specific variable in the postgresql configuration
file.

If it's not too much trouble, I have another question: my name is Anderson
Antunes. I live in Brazil. I'm doing research for a master's project
about pseudo
random numbers and would like to know more information about the random()
function used to randomly order a set of records. I tried to search through
the site that offers the source code but I couldn't identify the exact
implementation of this function.

[image: image.png]
https://doxygen.postgresql.org/
[image: image.png]

Can you help me?

Em qui., 24 de set. de 2020 às 18:07, Bruce Momjian <bruce@momjian.us>
escreveu:

On Tue, Sep 22, 2020 at 06:57:13PM +0000, PG Bug reporting form wrote:

The following bug has been logged on the website:

Bug reference: 16628
Logged by: Anderson Antunes
Email address: anderson.ant.oli@gmail.com
PostgreSQL version: 9.5.0
Operating system: Linux
Description:

Hi,

Is there any possibility of developing a function to retrieve hostname

and

the connection string?

Example:

select get_host_name ();

You can get the server IP address, but not the host name:

test=> SELECT inet_server_addr();
inet_server_addr
------------------
127.0.0.1

select get_string_connection ();

Uh, the connection information is parsed by libpq, and visible in psql:

test=> \conninfo You are connected to database "test" as user
"postgres" on host "localhost" (address "127.0.0.1")
at port "5432".

but the server only sees the result. You can see the server port
number:

test=> SELECT inet_server_port();
inet_server_port
------------------
5432

I can't figure out how to query the SSL mode via SQL. Does this help?

--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EnterpriseDB https://enterprisedb.com

The usefulness of a cup is in its emptiness, Bruce Lee

--
Atenciosamente,
Anderson Antunes
Bento Gonçalves
(53) 9142-2910

On Sat, Apr 22, 2023 at 11:57:06AM -0300, Anderson Antunes wrote:

I'm sorry for not responding earlier. She ended up falling into spam. I solved
it by creating a specific variable in the postgresql configuration file.

If it's not too much trouble, I have another question: my name is Anderson
Antunes. I live in Brazil. I'm doing research for a master's project about
pseudo random numbers and would like to know more information about the random
() function used to randomly order a set of records. I tried to search through
the site that offers the source code but I couldn't identify the exact
implementation of this function. 

Looks like random() internally is called drandom():

\x
\df+ random
List of functions
-[ RECORD 1 ]-------+-----------------
Schema | pg_catalog
Name | random
Result data type | double precision
Argument data types |
Type | func
Volatility | volatile
Parallel | restricted
Owner | postgres
Security | invoker
Access privileges |
Language | internal
--> Internal name | drandom
Description | random value

--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com

Embrace your flaws. They make you human, rather than perfect,
which you will never be.

I'll look. Thanks.

Em sex., 28 de abr. de 2023 às 15:47, Bruce Momjian <bruce@momjian.us>
escreveu:

On Sat, Apr 22, 2023 at 11:57:06AM -0300, Anderson Antunes wrote:

I'm sorry for not responding earlier. She ended up falling into spam. I

solved

it by creating a specific variable in the postgresql configuration file.

If it's not too much trouble, I have another question: my name is

Anderson

Antunes. I live in Brazil. I'm doing research for a master's project

about

pseudo random numbers and would like to know more information about the

random

() function used to randomly order a set of records. I tried to search

through

the site that offers the source code but I couldn't identify the exact
implementation of this function.

Looks like random() internally is called drandom():

\x
\df+ random
List of functions
-[ RECORD 1 ]-------+-----------------
Schema | pg_catalog
Name | random
Result data type | double precision
Argument data types |
Type | func
Volatility | volatile
Parallel | restricted
Owner | postgres
Security | invoker
Access privileges |
Language | internal
--> Internal name | drandom
Description | random value

--
Bruce Momjian <bruce@momjian.us> https://momjian.us
EDB https://enterprisedb.com

Embrace your flaws. They make you human, rather than perfect,
which you will never be.

--
Atenciosamente,
Anderson Antunes
Bento Gonçalves
(53) 9142-2910