pgsql: Document random page cost is only 4x seqeuntial, and not 40x.
Document random page cost is only 4x seqeuntial, and not 40x.
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master
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http://git.postgresql.org/pg/commitdiff/c1d9df4fa227781b31be44a5a3024865a7f48049
Modified Files
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doc/src/sgml/config.sgml | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)
On 14 February 2012 21:55, Bruce Momjian <bruce@momjian.us> wrote:
Document random page cost is only 4x seqeuntial, and not 40x.
Branch
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masterDetails
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http://git.postgresql.org/pg/commitdiff/c1d9df4fa227781b31be44a5a3024865a7f48049Modified Files
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doc/src/sgml/config.sgml | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)
This change does say that it is 40 times slower:
"The default value can be thought of as modeling random access as 40
times slower than sequential..."
--
Thom
On Tue, Feb 14, 2012 at 10:44:08PM +0000, Thom Brown wrote:
On 14 February 2012 21:55, Bruce Momjian <bruce@momjian.us> wrote:
Document random page cost is only 4x seqeuntial, and not 40x.
Branch
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masterDetails
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http://git.postgresql.org/pg/commitdiff/c1d9df4fa227781b31be44a5a3024865a7f48049Modified Files
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doc/src/sgml/config.sgml | � 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)This change does say that it is 40 times slower:
"The default value can be thought of as modeling random access as 40
times slower than sequential..."
I meant to say that it documents why we have a default of 4x, not 40x.
(In fact, real world, it is probably 100x.)
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
On 14 February 2012 22:46, Bruce Momjian <bruce@momjian.us> wrote:
On Tue, Feb 14, 2012 at 10:44:08PM +0000, Thom Brown wrote:
On 14 February 2012 21:55, Bruce Momjian <bruce@momjian.us> wrote:
Document random page cost is only 4x seqeuntial, and not 40x.
Branch
------
masterDetails
-------
http://git.postgresql.org/pg/commitdiff/c1d9df4fa227781b31be44a5a3024865a7f48049Modified Files
--------------
doc/src/sgml/config.sgml | 20 ++++++++++++++++++++
1 files changed, 20 insertions(+), 0 deletions(-)This change does say that it is 40 times slower:
"The default value can be thought of as modeling random access as 40
times slower than sequential..."I meant to say that it documents why we have a default of 4x, not 40x.
(In fact, real world, it is probably 100x.)
Hmmm.. okay. I haven't managed to test that myself, but I'll take
your word for it. :)
--
Thom