Subject: Re: how to make duplicate finding query faster?
To: pgsql-admin@lists.postgresql.org
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From: Holger Jakobs <holger@jakobs.com>
Message-ID: <cd50c237-2062-a18b-374d-b2399830b988@jakobs.com>
Date: Wed, 30 Dec 2020 12:18:06 +0100
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From: Holger Jakobs <holger@jakobs.com>
To: pgsql-admin@lists.postgresql.org
Message-ID: <cd50c237-2062-a18b-374d-b2399830b988@jakobs.com>
Subject: Re: how to make duplicate finding query faster?
References: <CALg-PKBPQPBMbNAxf-pF0OLbYs0exC7Vf2Sn3hNPUAJ7Q=mPtA@mail.gmail.com>
 <5bf642e4-eb22-8eba-e96d-5b33b5010b03@jakobs.com>
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Am 30.12.20 um 09:59 schrieb Sachin Kumar:
> HI Mr. Holger,
>
> This will not suffice our requirement. we have to validate that there=20
> would=C2=A0not be any duplicate value in DB. we have done that earlier =
by=20
> leaving DB to check if there is any duplicate and found duplicate=20
> value in DB.
>
> we have a table "card"=C2=A0 and a single column "number " which we are=
=20
> updated with a csv file with 600k numbers and require no duplicate=20
> number should=C2=A0be there in the table.
>
> Please if can have a faster query can help us in achieving=C2=A0this=20
> requirement.
>
>
Quote: leaving DB to check if there is any duplicate and found duplicate =

value in DB

No, that's not possible with PostgreSQL. If you have a Primary Key or a=20
Unique Constraint, no duplicates will be allowed by the DB.

There must be a different reason.


--=20
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012


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    <div class=3D"moz-cite-prefix">Am 30.12.20 um 09:59 schrieb Sachin
      Kumar:<br>
    </div>
    <blockquote type=3D"cite"
cite=3D"mid:CALg-PKAwst1C2fF9ZBY+Dog0D2CZ7P-xppG41b3DnV62R=3DSxwQ@mail.gm=
ail.com">
      <meta http-equiv=3D"content-type" content=3D"text/html; charset=3DU=
TF-8">
      <div dir=3D"ltr">HI Mr. Holger,
        <div><br>
        </div>
        <div>This will not suffice our requirement. we have to validate
          that there would=C2=A0not be any duplicate value in DB. we have=

          done that earlier by leaving DB to check if there is any
          duplicate and found duplicate value in DB.=C2=A0</div>
        <div><br>
        </div>
        <div>we have a table "card"=C2=A0 and a single column "number " w=
hich
          we are updated with a csv file with 600k numbers and require
          no duplicate number should=C2=A0be there in the table.</div>
        <div><br>
        </div>
        <div>Please if can have a faster query can help us in
          achieving=C2=A0this requirement.</div>
        <div><br>
        </div>
        <div><br>
        </div>
        <img src=3D"http://s.bl-1.com/LYSl4cd.gif" moz-do-not-send=3D"tru=
e"
          width=3D"1" height=3D"1"></div>
    </blockquote>
    <p>Quote: leaving DB to check if there is any duplicate and found
      duplicate value in DB</p>
    <p>No, that's not possible with PostgreSQL. If you have a Primary
      Key or a Unique Constraint, no duplicates will be allowed by the
      DB.</p>
    <p>There must be a different reason.<br>
    </p>
    <p><br>
    </p>
    <pre class=3D"moz-signature" cols=3D"72">--=20
Holger Jakobs, Bergisch Gladbach, Tel. +49-178-9759012</pre>
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