Re: Use ctid in where clause in update from statement - Mailing list pgsql-general
This is just a very simplified sample and doesn’t makes sense, but it shows the execution plan. The original query is more complex. It selects more values and updates more columns.
Dirk
fon +49 2202 2401-1197 --
Dirk Mika
Software Developer
mika:timing GmbH
Strundepark - Kürtener Str. 11b
51465 Bergisch Gladbach
Germany
dirk.mika@mikatiming.de
www.mikatiming.deAG Köln HRB 47509 * WEEE-Reg.-Nr. DE 90029884
Geschäftsführer: Harald Mika, Jörg Mika
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Von: Achilleas Mantzios <achill@matrix.gatewaynet.com>
Datum: Montag, 1. Juli 2019 um 11:50
An: "pgsql-general@lists.postgresql.org" <pgsql-general@lists.postgresql.org>
Betreff: Re: Use ctid in where clause in update from statement
On 1/7/19 12:13 μ.μ., Dirk Mika wrote:
UPDATE test_large d
SET grp = s.grp
FROM (SELECT ctid, test_large.*
FROM test_large
WHERE grp = 1) s
WHERE d.ctid = s.ctid;
Besides, what the above does is select for rows that have grp=1 and then set grp to the same value.
BR
Dirk
--
Dirk Mika
Software Developer
mika:timing GmbH
Strundepark - Kürtener Str. 11b
51465 Bergisch Gladbach
Germanyfon +49 2202 2401-1197
dirk.mika@mikatiming.de
www.mikatiming.deAG Köln HRB 47509 * WEEE-Reg.-Nr. DE 90029884
Geschäftsführer: Harald Mika, Jörg Mika
--
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt
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