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Best way to select a random row from a derived table - Mailing list pgsql-hackers

From	Ryan Murphy
Subject	Best way to select a random row from a derived table
Date	January 28, 2018 12:39:33
Msg-id	CAHeEsBfP2DL2B+VwDZSoxMjz7KPTD2oFg0RDE-SRJ+gRn4wzXA@mail.gmail.com Whole thread Raw
Responses	Re: Best way to select a random row from a derived table Re: Best way to select a random row from a derived table Re: Best way to select a random row from a derived table Re: Best way to select a random row from a derived table
List	pgsql-hackers

Hello hackers and postgressers,

I am aware of 2 ways to select a random row from a table:

1) select * from table_name order by random() limit 1;

-- terribly inefficient

2) select * from table_name tablesample system_rows(1) limit 1;

-- only works on tables, not views or subqueries

Is there an option that is reasonably efficient and can be used on views and subqueries?

Thanks!

Ryan

From: Jeff Davis
Date: 28 January 2018, 12:06:59
Subject: Re: JIT compiling with LLVM v9.0

From: Fabien COELHO
Date: 28 January 2018, 14:10:11
Subject: Re: General purpose hashing func in pgbench