Обсуждение: Equivalent of or condition in where clause

On Thu, Apr 01, 2021 at 02:11:12PM +0530, Firthouse banu wrote:
> Hi all,
> 
> Need a suggestion. I have a update query in Postgres which is equivalent to
> below example. Since query is having multiple or conditions and our tables
> are very large it’s taking forever to run. Can you guys suggest me what can
> be replaced with or condition in below example.
> 
> Update table_name IA set
> Column_1 = SC. Column_1,
> Column_2 = SC. Column_2,
> Column_3 = SC. Column_3
> From (select statement ) SC
> Where
> IA. Column4=! SC. Column4 or
> IA.column5  = ! SC. Column5 or
> IA.column6 = ! SC. Column6 or
> IA.column7 = ! SC. Column7
> And IA. Column8 = SC. Column8
> And IA. Column9 = SC. Column9;

I don't think this query is doing what you think it's doing.  You should
probably put parenthesis around the OR-ed predicates if you don't want this
behavior:

 select 1 != 2 or 2 != 3 and 3 = 4 and 4 = 5;
 ?column?
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 t