Please help to speed up UPDATE statement

Started by Andrusalmost 21 years ago2 messagesgeneral
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#1Andrus
noeetasoftspam@online.ee

The following statement runs VERY slowly on large tables.

Any idea how to speed it up ?

UPDATE rid SET dokumnr=NULL WHERE
dokumnr NOT IN (SELECT dokumnr FROM dok);

Tables:

CREATE TABLE dok ( dokumnr INTEGER,
CONSTRAINT dok_pkey PRIMARY KEY (dokumnr) );

CREATE TABLE rid ( dokumnr INTEGER );
CREATE INDEX rid_dokumnr_idx ON rid (dokumnr);

Andrus

#2Bob
luckyratfoot@gmail.com
In reply to: Andrus (#1)
Re: Please help to speed up UPDATE statement

On Apr 12, 2005 9:40 AM, Andrus <noeetasoftspam@online.ee> wrote:

The following statement runs VERY slowly on large tables.

Any idea how to speed it up ?

UPDATE rid SET dokumnr=NULL WHERE
dokumnr NOT IN (SELECT dokumnr FROM dok);

Tables:

CREATE TABLE dok ( dokumnr INTEGER,
CONSTRAINT dok_pkey PRIMARY KEY (dokumnr) );

CREATE TABLE rid ( dokumnr INTEGER );
CREATE INDEX rid_dokumnr_idx ON rid (dokumnr);

Andrus

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