Re: Updated posix fadvise patch v19 - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Updated posix fadvise patch v19
Date
Msg-id 603c8f070811182001r3870122ep3f4ff69c1c93ef30@mail.gmail.com
Whole thread Raw
In response to Re: Updated posix fadvise patch v19  ("Robert Haas" <robertmhaas@gmail.com>)
Responses Re: Updated posix fadvise patch v19  (Grzegorz Jaskiewicz <gj@pointblue.com.pl>)
List pgsql-hackers
Obviously that went too soon.

> In config.sgml, the documentation is good, but suffers from a slightly
> informal style.  There are a lot of places where commas seem
> appropriate but are not present.  Suggested changes by paragraph:
>
> 1. Replace last sentence: "Raising this value will cause PostgreSQL to initiate

...more I/O operations in parallel."

2. "Typically, this parameter should be set to the number of separate
drives comprising a RAID 0 stripe or RAID 1 mirror or any combination.For RAID 5, it should be set to the number of
drivesexcluding the
 
parity drive.   However, the optimal value varies based on the
effectiveness of the RAID controller or software implementation, and
may require some experimentation."

3. "For more exotic systems, such as memory-based storage or a RAID
array which is limited by bus bandwidth, the correct value might be
the number of paths available instead; again, experimentation is
recommended."

4. Insert comma after "However" in third sentence.  Replace last
sentence with: "On these operating systems, setting
effective_io_concurrency to a value greater than 1 will incur some CPU
overhead without improving perforamance."

...Robert


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