On Wednesday, 5 November, 2014 22:23, James Lowden said:
>On Wed, 05 Nov 2014 08:24:47 -0700, "Keith Medcalf"
>wrote:
>> The two queries are different. They may end up with the same result,
>> but you are asking different questions. In the first you are
>> returning only
On Wed, 05 Nov 2014 08:24:47 -0700
"Keith Medcalf" wrote:
> The two queries are different. They may end up with the same result,
> but you are asking different questions. In the first you are
> returning only matching rows. In the later you are requesting a
> projection
Can you please run ANALYZE then try the plans again ?
This was just after running ANALYZE :)
the fact that they produce the exact same answer is simply by virtue of
your WHERE clause being specifically that
Of course, I understand, that's what I've meant - the plan shouldn't
differ for
On Wednesday, 5 November, 2014 05:14, vita...@yourcmc.ru said:
>After playing a little with SQLite as a DBMS for Bugzilla, I've
>discovered that LEFT/INNER join affects query plan in a bad way even for
>semantically equal queries:
>SELECT * FROM bugs b INNER JOIN profiles p ON
On Wed, 2014-11-05 at 16:00 +0200, RSmith wrote:
> On 2014/11/05 15:26, David Woodhouse wrote:
> > On Wed, 2014-11-05 at 15:13 +0200, RSmith wrote:
> > I don't think it's anything to do with the table data being special,
> is it? Isn't it generically true that for any LEFT JOIN of
> > a,b WHERE
On 2014/11/05 15:26, David Woodhouse wrote:
On Wed, 2014-11-05 at 15:13 +0200, RSmith wrote:
I don't think it's anything to do with the table data being special, is it? Isn't it generically true that for any LEFT JOIN of
a,b WHERE b.anything IS NOT NULL, the results are going to be equal with
On Wed, 2014-11-05 at 15:13 +0200, RSmith wrote:
> On 2014/11/05 14:13, vita...@yourcmc.ru wrote:
> > Hi!
> >
> > After playing a little with SQLite as a DBMS for Bugzilla, I've discovered
> > that LEFT/INNER join affects query plan in a bad way
> > even for semantically equal queries:
> >
> >
On Wed, Nov 5, 2014 at 8:12 AM, Clemens Ladisch wrote:
>
> The WHERE expression then makes the outer join meaningless,
>
Thank you, Clemens - I missed that detail.
So the suggestion is that we should enhance the SQLite query planner to
detect when the WHERE clause requires
On 2014/11/05 14:13, vita...@yourcmc.ru wrote:
Hi!
After playing a little with SQLite as a DBMS for Bugzilla, I've discovered that LEFT/INNER join affects query plan in a bad way
even for semantically equal queries:
SELECT * FROM bugs b INNER JOIN profiles p ON p.userid=b.assigned_to WHERE
vita...@yourcmc.ru wrote:
> SELECT * FROM bugs b LEFT JOIN profiles p ON p.userid=b.assigned_to WHERE
> p.login_name='vita...@yourcmc.ru'
>
> Query plan:
> SCAN TABLE bugs AS b
> SEARCH TABLE profiles AS p USING INTEGER PRIMARY KEY (rowid=?)
>
> Which is of course very slow.
>
> Maybe you'll
On Wed, Nov 5, 2014 at 7:13 AM, wrote:
> Hi!
>
> After playing a little with SQLite as a DBMS for Bugzilla, I've discovered
> that LEFT/INNER join affects query plan in a bad way even for semantically
> equal queries:
>
I'm not sure what you mean by "semantically equal", but
On 5 Nov 2014, at 12:13pm, vita...@yourcmc.ru wrote:
> Which is of course very slow.
Can you please run ANALYZE then try the plans again ?
Simon.
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Hi!
After playing a little with SQLite as a DBMS for Bugzilla, I've
discovered that LEFT/INNER join affects query plan in a bad way even for
semantically equal queries:
SELECT * FROM bugs b INNER JOIN profiles p ON p.userid=b.assigned_to
WHERE p.login_name='vita...@yourcmc.ru'
Query plan:
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