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Re: SQL indices a WC format bump and 1.7

From: Mark Phippard <markphip_at_gmail.com>
Date: Fri, 2 Sep 2011 12:02:02 -0400

On Fri, Sep 2, 2011 at 11:42 AM, Philip Martin
<philip.martin_at_wandisco.com> wrote:
> Hyrum K Wright <hyrum.wright_at_wandisco.com> writes:
>
>>   sqlite> select * from sqlite_master where type = 'index' and
>> tbl_name = 'WCROOT';
>>   index|sqlite_autoindex_WCROOT_1|WCROOT|8|
>>   index|I_LOCAL_ABSPATH|WCROOT|9|CREATE UNIQUE INDEX I_LOCAL_ABSPATH
>> ON WCROOT (local_abspath)
>>
>> would both indicate there are two indices on the WCROOT table, though
>> we only define one.  I believe one of these indices is due to the
>> UNIQUEness of the local_abspath column.
>
> Yes, that's why I think we can delete them.  However we rarely write to
> these tables so the overhead of having the superfluous index is
> negligible.  There is no real need to remove them from 1.7 if people
> would prefer to make a more minimal change for 1.7.

I do not know about SQLite, but in other databases I have worked with,
the database engine is intelligent enough to not create anything
superfluous in this sort of scenario where the index you want to
create already exists.

-- 
Thanks
Mark Phippard
http://markphip.blogspot.com/
Received on 2011-09-02 18:02:50 CEST

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