Postgres Pro
Downloads
Home   >   mailing lists

Re: How should I specify work_mem/max_worker_processes if I want to do big queries now and then? - Mailing list pgsql-general

From James(王旭)
Subject Re: How should I specify work_mem/max_worker_processes if I want to do big queries now and then?
Date
Msg-id tencent_74BC96994E7316FA7599BF68@qq.com
Whole thread Raw
In response to Re: How should I specify work_mem/max_worker_processes if I want todo big queries now and then?  (Imre Samu <pella.samu@gmail.com>)
List pgsql-general
Tree view
Thanks Imre, this is a very important comment, 128 bits is much smaller than 45*8+2=362.

Very glad to know that, thank you very much!

James
 
 
------------------ Original ------------------
Date:  Thu, Nov 21, 2019 08:39 PM
To:  "James(王旭)"<wangxu@gu360.com>;
Cc:  "pgsql-general"<pgsql-general@postgresql.org>;
Subject:  Re: How should I specify work_mem/max_worker_processes if I want to do big queries now and then?
 
>  uuid character varying(45) NOT NULL,

Just a comment.
IF this is a real UUID ( RFC 4122, ISO/IEC 9834-8:2005 ) ; 
THEN you can use the built in  "UUID Type"  https://www.postgresql.org/docs/11/datatype-uuid.html


"UUID would be the fastest because its 128 bits -> 16 bytes and comparisons are done numerically."
The smaller size can be important for your index size ! :   "quotes_pkey PRIMARY KEY (symbol_id, uuid);"

Imre

pgsql-general by date:

Previous
From: Dave Hughes
Date:
Subject: Re: Help with configuring pgAudit
Next
From: Pavel Stehule
Date:
Subject: Re: Adding LIMIT changes PostgreSQL plan from good to a bad one