Re: Bottlenecks with large number of relation segment files - Mailing list pgsql-general

From Florian Weimer
Subject Re: Bottlenecks with large number of relation segment files
Date
Msg-id 51FF8EC1.9050209@redhat.com
Whole thread Raw
In response to Re: Bottlenecks with large number of relation segment files  (John R Pierce <pierce@hogranch.com>)
Responses Re: Bottlenecks with large number of relation segment files  (KONDO Mitsumasa <kondo.mitsumasa@lab.ntt.co.jp>)
List pgsql-general
On 08/05/2013 10:42 AM, John R Pierce wrote:
> On 8/5/2013 1:01 AM, KONDO Mitsumasa wrote:
>> When we open file, ext3 or ext4 file system seems to sequential search
>> inode for opening file in file directory.
>
> no, ext3/4 uses H-tree structures to search directories over 1 block
> long quite efficiently.

And the Linux dentry cache is rather aggressive, so most of the time,
only the in-memory hash table will be consulted.  (The dentry cache only
gets flushed on severe memory pressure.)

--
Florian Weimer / Red Hat Product Security Team


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