On Wednesday, October 2, 2013, Richard Hipp wrote:
>
> In the current beta (at http://www.sqlite.org/download.html) the function
> is either unlikely(X) or likelihood(X,Y). In the second form, Y must be a
> floating point constant between 0.0 and 1.0, inclusive. The first form is
> equivalent to
On 02/10/2013 2:19 AM, Baruch Burstein wrote:
On Fri, Sep 13, 2013 at 5:29 AM, Ryan Johnson
wrote:
-- Join cardinality: Bach was a *very* prolific composer whose output
likely dwarfs the (surviving) output of his contemporaries
select p.title, c.name, p.year from
On Wed, Oct 2, 2013 at 1:40 AM, Nico Williams wrote:
> On Tuesday, September 10, 2013, Richard Hipp wrote:
>
> > SURVEY QUESTION:
> >
> > The question for today is what to call this magic hint function:
> >
> > (1) unlikely(EXPR)
> > (2) selective(EXPR)
> > (3)
On Fri, Sep 13, 2013 at 5:29 AM, Ryan Johnson
wrote:
> -- Join cardinality: Bach was a *very* prolific composer whose output
> likely dwarfs the (surviving) output of his contemporaries
> select p.title, c.name, p.year from composers c join pieces p on p.c_id =
> c.id
On Tuesday, September 10, 2013, Richard Hipp wrote:
> SURVEY QUESTION:
>
> The question for today is what to call this magic hint function:
>
> (1) unlikely(EXPR)
> (2) selective(EXPR)
> (3) seldom(EXPR)
> (4) seldom_true(EXPR)
> (5) usually_not_true(EXPR)
(1), on account of: it's already
Dr Hipp
I second Kyan's suggestion of a pseudo-comment hinting syntax:
... that the planner hint is not interleaved inside normal SQL
> syntax. Instead I propose a special comment-like syntax instead, as
> Oracle's /*+ */ or --+, but replacing "+" with another symbol, e.g. ">":
>
Having had to
On 10.09.2013 21:26, Richard Hipp wrote:
SURVEY QUESTION:
The question for today is what to call this magic hint function:
(1) unlikely(EXPR)
(2) selective(EXPR)
(3) seldom(EXPR)
(4) seldom_true(EXPR)
(5) usually_not_true(EXPR)
A function call like proposed is much better than
On 12/09/2013 7:12 PM, Simon Slavin wrote:
On 12 Sep 2013, at 11:35pm, Roger Binns wrote:
On 12/09/13 05:03, Gabor Grothendieck wrote:
Perhaps indexing the expression in question would be an alternative
that would keep the performance info separate from the select.
On 12 Sep 2013, at 11:35pm, Roger Binns wrote:
> On 12/09/13 05:03, Gabor Grothendieck wrote:
>> Perhaps indexing the expression in question would be an alternative
>> that would keep the performance info separate from the select.
>
> I'd rather just do 'ANALYZE query'
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On 12/09/13 05:03, Gabor Grothendieck wrote:
> Perhaps indexing the expression in question would be an alternative
> that would keep the performance info separate from the select.
I'd rather just do 'ANALYZE query' and have SQLite go off and do
PostgreSQL supports
create index on ( )
Note that it allows an expression and not just a column name.
See:
http://www.postgresql.org/docs/9.1/static/sql-createindex.html
Perhaps indexing the expression in question would be an alternative
that would keep the performance info separate
Richard wrote:
The question for today is what to call this magic hint function:
(1) unlikely(EXPR)
(2) selective(EXPR)
(3) seldom(EXPR)
(4) seldom_true(EXPR)
(5) usually_not_true(EXPR)
Please feel free to suggest other names if you think of any.
I dislike #4 and#5, but what about one
probability(EXPR, value)
- Would force the user to set their best guess. I would think that the
users guess would be more accurate than a general guess? What's
considered unlikely for the users data, 0.05? 0.20?
I would prefer if the mechanism could be handled with pragmas (or
something)
On Sep 10, 2013, at 6:23 PM, Scott Robison wrote:
> I think I prefer something along the lines of "unlikely" or "likely". The
> problem with a term like "selective" (at least in my brain) is that it
> doesn't imply (for the single argument version) in what way it is
On Tue, 10 Sep 2013 15:26:51 -0400, Richard Hipp
wrote:
>SURVEY QUESTION:
>
>The question for today is what to call this magic hint function:
>
>(1) unlikely(EXPR)
>(2) selective(EXPR)
>(3) seldom(EXPR)
>(4) seldom_true(EXPR)
>(5) usually_not_true(EXPR)
>
>Please feel free
On Wed, Sep 11, 2013 at 5:36 PM, Kevin Benson wrote:
> On Tue, Sep 10, 2013 at 3:26 PM, Richard Hipp wrote:
> > SURVEY QUESTION:
> > (1) unlikely(EXPR)
> > (2) selective(EXPR)
> > (3) seldom(EXPR)
> > (4) seldom_true(EXPR)
> > (5)
On Tue, Sep 10, 2013 at 3:26 PM, Richard Hipp wrote:
> SURVEY QUESTION:
>
> The question for today is what to call this magic hint function:
>
> (1) unlikely(EXPR)
> (2) selective(EXPR)
> (3) seldom(EXPR)
> (4) seldom_true(EXPR)
> (5) usually_not_true(EXPR)
(6)
On 11.09.2013 16:07, Ryan Johnson wrote:
Perhaps you meant "demote" rather than "degrade" ? That would be a
better fit (an external action that does not necessarily make the
object worse or less useful), and less vague, but it still carries a
negative connotation.
"demote" sounds fine to me,
I suggest a verb to express what the function is actually doing, namely
to reduce its argument in rank or degree for the query planner:
DEGRADE
1. to reduce in worth, character, etc; disgrace;
2. to reduce in rank, status, or degree; remove from office;
3. to reduce in strength, quality,
> -Original Message-
> From: sqlite-users-boun...@sqlite.org
> [mailto:sqlite-users-boun...@sqlite.org] On Behalf
> Of Richard Hipp
> Sent: Tuesday, September 10, 2013 2:27 PM
> To: General Discussion of SQLite Database
> Subject: [sqlite] Hints for the query planner
>
> There is a
I also think it should not be directly in the SQL. I like the
not-really-a-comment syntax. Another option might be a few PRAGMAs,
something like
PRAGMA hint("table1.col1 IN (1,2,5)", 0.05);
PRAGMA hint("table1.col2 LIKE '%bach%'". 0.4);
these would add the hints to an internal table. When
(6) maybe(EXPR)
-Ursprüngliche Nachricht-
Von: Richard Hipp [mailto:d...@sqlite.org]
Gesendet: Dienstag, 10. September 2013 21:27
An: General Discussion of SQLite Database
Betreff: [sqlite] Hints for the query planner
There is a survey question at the bottom of this message. But first
How about:
maybe(COLUMN LIKE '%pattern%',.95)
or (as percent using integer value in 0..100)
maybe(COLUMN LIKE '%pattern%',95)
with a default value of (possibly) 50% (or .5) for the optional second arg?
-Original Message-
From: Richard Hipp
Sent: Tuesday, September 10, 2013 10:26 PM
On Sep 10, 2013, at 12:26 PM, Richard Hipp wrote:
> SURVEY QUESTION:
>
> The question for today is what to call this magic hint function:
>
> (1) unlikely(EXPR)
> (2) selective(EXPR)
> (3) seldom(EXPR)
> (4) seldom_true(EXPR)
> (5) usually_not_true(EXPR)
>
> Please feel
As I was reading this, I said to myself, "what they really need is a confidence
value." Then I read the end and, there it was! A confidence value. Ok.. not
exactly confidence, but I think you get my meaning.
It seems to me that you're allowing the query writer to substitute personal
Hello Dr Hipp,
First of all, I apologize for this rather off-topic suggestion knowing that
you may have already implemented the syntax you describe, but there is an
IMHO good reason for it, read ahead.
On Tue, Sep 10, 2013 at 10:26 PM, Richard Hipp wrote:
> SELECT DISTINCT
How about three, where two are just overloaded, or rather syntactic sugar, for
the main declaration:
unlikely(expr)
likely(expr)
likelihood(expr, rate)
Where unlikely(expr) -> likelihood(expr, 0.05)
likely(expr) -> likelihood(expr, 0.95)
I would presume that the rate is the expected
On 10 Sep 2013, at 10:48pm, Tim Streater wrote:
> likelihood (EXPR, value)
Best I've seen so far. I know it makes no sense without the second parameter
but I think if you're going to make use of a special non-standard optimisation
system you can be expected to know
Or...
unlikely(expr (, prob=0.05)) ==> likelihood (...)
(sent from a mobile device - please excuse brevity, typos, and top-posting)
- stephan beal
http://wanderinghorse.net
On Sep 11, 2013 12:51 AM, "Stephan Beal" wrote:
> Plus an overload: unlikely(expr) ==>
Seconded.
-Original Message-
From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org]
On Behalf Of Simon Slavin
Sent: Tuesday, September 10, 2013 3:46 PM
To: General Discussion of SQLite Database
Subject: Re: [sqlite] Hints for the query planner
On 10 Sep 2013
Plus an overload: unlikely(expr) ==> likelihood (expr, 0.05)
(sent from a mobile device - please excuse brevity, typos, and top-posting)
- stephan beal
http://wanderinghorse.net
On Sep 10, 2013 11:49 PM, "Tim Streater" wrote:
> On 10 Sep 2013 at 20:26, Richard Hipp
On 10 Sep 2013 at 20:26, Richard Hipp wrote:
> SURVEY QUESTION:
>
> The question for today is what to call this magic hint function:
>
> (1) unlikely(EXPR)
> (2) selective(EXPR)
> (3) seldom(EXPR)
> (4) seldom_true(EXPR)
> (5) usually_not_true(EXPR)
>
> Please feel free to
I think I prefer something along the lines of "unlikely" or "likely". The
problem with a term like "selective" (at least in my brain) is that it
doesn't imply (for the single argument version) in what way it is being
selective.
If a negative form of the magic function is used ("unlikely",
> (1) unlikely(EXPR)
> (2) selective(EXPR)
> (3) seldom(EXPR)
> (4) seldom_true(EXPR)
> (5) usually_not_true(EXPR)
>
>
I quite like (2) "selective". I think it's reasonably descriptive on its
own, and also works well with the optional second argument.
In Bayesian statistics there is a term "prior", prior probability.
From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on
behalf of Richard Hipp [d...@sqlite.org]
Sent: Tuesday, September 10, 2013 3:26 PM
To: General Discussion of
Hi Richard,
What about "probability" or "likelyhood"? This works in both the case where
the likelyhood is great as well as when it is low. From the list you
provided, I would pick "unlikely".
Kind regards,
Philip Bennefall
- Original Message -
From: "Richard Hipp"
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