Re: [HACKERS] Proposal: Improve bitmap costing for lossy pages - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [HACKERS] Proposal: Improve bitmap costing for lossy pages
Date
Msg-id CA+Tgmoa7hxMBDVmWSajs4DjqXGtKvCQUqrAbEe9m8ZOxqJSsag@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] Proposal: Improve bitmap costing for lossy pages  (Dilip Kumar <dilipbalaut@gmail.com>)
Responses Re: [HACKERS] Proposal: Improve bitmap costing for lossy pages
List pgsql-hackers
On Sun, Sep 17, 2017 at 7:04 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
> I used  lossy_pages = max(0, total_pages - maxentries / 2). as
> suggesed by Alexander.

Does that formula accurately estimate the number of lossy pages?

The performance results look good, but that's a slightly different
thing from whether the estimate is accurate.

+    nbuckets = tbm_calculate_entires(maxbytes);

entires?

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

pgsql-hackers by date:

Previous
From: Mario Fernando Guerrero Díaz
Date:
Subject: Re: [HACKERS] Postgres 9.6 Logical and Fisical replication
Next
From: Tom Lane
Date:
Subject: Re: [HACKERS] [COMMITTERS] pgsql: Allow multiple tables to be specified in one VACUUM or ANALYZE c