Re: Idea for getting rid of VACUUM FREEZE on cold pages

On Fri, Jun 4, 2010 at 11:45 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
>> In my experience with my own environment, I can honestly say that
>> it's clear that not freezing tuples quickly adds more cost than
>> running with cassert on.  If we had to run in production with one or
>> the other, I would definitely choose cassert from a performance
>> perspective; which one would do more to find bugs?  Why do we view
>> them so differently?
>
> The reason for not recommending cassert in production builds is not
> cost but stability.  Per the fine manual:
>
>         Also, having the tests turned on won't necessarily enhance the
>         stability of your server!  The assertion checks are not categorized
>         for severity, and so what might be a relatively harmless bug will
>         still lead to server restarts if it triggers an assertion
>         failure.  This option is not recommended for production use, but
>         you should have it on for development work or when running a beta
>         version.

We routinely castigate people for benchmarking done with cassert
turned on, and tell them their numbers are meaningless.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company