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  1. Fix typos in README.dependencies

  1. Fix a typo in README.dependencies

    atorikoshi <torikoshi_atsushi_z2@lab.ntt.co.jp> — 2017-06-05T02:52:29Z

    Hi,

I found below formula to compute selectivities, but
I think the last Probability 'P(b=?)' should be 'P(c=?)'.

>  P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))

Attached patch fixes it, and it also adds some spaces
following another formula which is on line 86 and
computes P(a=?, b=?).

Regards,

--
Atsushi Torikoshi
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

  2. Re: Fix a typo in README.dependencies

    Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> — 2017-06-05T12:24:08Z

    On Mon, Jun 5, 2017 at 8:22 AM, atorikoshi
<torikoshi_atsushi_z2@lab.ntt.co.jp> wrote:
> Hi,
>
> I found below formula to compute selectivities, but
> I think the last Probability 'P(b=?)' should be 'P(c=?)'.
>
>>  P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))
>
>
> Attached patch fixes it, and it also adds some spaces
> following another formula which is on line 86 and
> computes P(a=?, b=?).

Agree. Also using "d" for "degree of functional dependence (b=>c) as
well is confusing. We are already using "d" for "degree of functional
dependence (a=>b). Here' patch to use "d'" instead of "d".

-- 
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company

  3. Re: Fix a typo in README.dependencies

    Alvaro Herrera <alvherre@2ndquadrant.com> — 2017-06-22T21:28:45Z

    Ashutosh Bapat wrote:
> On Mon, Jun 5, 2017 at 8:22 AM, atorikoshi
> <torikoshi_atsushi_z2@lab.ntt.co.jp> wrote:
> > Hi,
> >
> > I found below formula to compute selectivities, but
> > I think the last Probability 'P(b=?)' should be 'P(c=?)'.
> >
> >>  P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))
> >
> >
> > Attached patch fixes it, and it also adds some spaces
> > following another formula which is on line 86 and
> > computes P(a=?, b=?).
> 
> Agree. Also using "d" for "degree of functional dependence (b=>c) as
> well is confusing. We are already using "d" for "degree of functional
> dependence (a=>b). Here' patch to use "d'" instead of "d".

Since the surrounding text uses single quotes to talk about each letter,
I thought it was better to use a new letter (e) so that we don't require
the "prime" notation, which would end up being either inconsistent,
confusing, stupid-looking, or combinations thereof.

Also, your proposed text had a slight mistake: it's not (b=>c) that
d' is for, but (a,b=>c). 

Pushed with those corrections.

Thanks for the reports and patches!

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

  4. Re: Fix a typo in README.dependencies

    Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> — 2017-06-23T06:37:44Z

    On Fri, Jun 23, 2017 at 2:58 AM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> Ashutosh Bapat wrote:
>> On Mon, Jun 5, 2017 at 8:22 AM, atorikoshi
>> <torikoshi_atsushi_z2@lab.ntt.co.jp> wrote:
>> > Hi,
>> >
>> > I found below formula to compute selectivities, but
>> > I think the last Probability 'P(b=?)' should be 'P(c=?)'.
>> >
>> >>  P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))
>> >
>> >
>> > Attached patch fixes it, and it also adds some spaces
>> > following another formula which is on line 86 and
>> > computes P(a=?, b=?).
>>
>> Agree. Also using "d" for "degree of functional dependence (b=>c) as
>> well is confusing. We are already using "d" for "degree of functional
>> dependence (a=>b). Here' patch to use "d'" instead of "d".
>
> Since the surrounding text uses single quotes to talk about each letter,
> I thought it was better to use a new letter (e) so that we don't require
> the "prime" notation, which would end up being either inconsistent,
> confusing, stupid-looking, or combinations thereof.

Makes sense.

>
> Also, your proposed text had a slight mistake: it's not (b=>c) that
> d' is for, but (a,b=>c).

Sorry for that.

>
> Pushed with those corrections.

Thanks.

-- 
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company

  5. Re: Fix a typo in README.dependencies

    atorikoshi <torikoshi_atsushi_z2@lab.ntt.co.jp> — 2017-06-23T06:37:52Z

    On 2017/06/23 6:28, Alvaro Herrera wrote:
> Ashutosh Bapat wrote:
>> On Mon, Jun 5, 2017 at 8:22 AM, atorikoshi
>> <torikoshi_atsushi_z2@lab.ntt.co.jp> wrote:
>>> Hi,
>>>
>>> I found below formula to compute selectivities, but
>>> I think the last Probability 'P(b=?)' should be 'P(c=?)'.
>>>
>>>>  P(a=?,b=?,c=?) = P(a=?,b=?) * (d + (1-d)*P(b=?))
>>>
>>>
>>> Attached patch fixes it, and it also adds some spaces
>>> following another formula which is on line 86 and
>>> computes P(a=?, b=?).
>>
>> Agree. Also using "d" for "degree of functional dependence (b=>c) as
>> well is confusing. We are already using "d" for "degree of functional
>> dependence (a=>b). Here' patch to use "d'" instead of "d".
>
> Since the surrounding text uses single quotes to talk about each letter,
> I thought it was better to use a new letter (e) so that we don't require
> the "prime" notation, which would end up being either inconsistent,
> confusing, stupid-looking, or combinations thereof.
>
> Also, your proposed text had a slight mistake: it's not (b=>c) that
> d' is for, but (a,b=>c).
>
> Pushed with those corrections.
>
> Thanks for the reports and patches!
>

Thanks!

--
Atsushi Torikoshi
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center