public inbox for [email protected]  
help / color / mirror / Atom feed
From: Tomas Vondra <[email protected]>
To: Corey Huinker <[email protected]>
To: Ashutosh Bapat <[email protected]>
Cc: [email protected]
Subject: Re: Statistics Import and Export
Date: Wed, 1 Nov 2023 21:07:27 +0100
Message-ID: <[email protected]> (raw)
In-Reply-To: <CADkLM=dTHVSrcGBAstjshoZBXKJgWjzN3Vj53KQ9fORqvkaN5Q@mail.gmail.com>
References: <CADkLM=cB0rF3p_FuWRTMSV0983ihTRpsH+OCpNyiqE7Wk0vUWA@mail.gmail.com>
	<CAExHW5uRNe856LPYH1eZFyeASv4Xs4-9d1Gqj+rzS+3StVGLxQ@mail.gmail.com>
	<CADkLM=c_iuAN19_94ikG5VeR_Z3LDkR6fKyeOz=ZKr44qweYjg@mail.gmail.com>
	<CADkLM=dTHVSrcGBAstjshoZBXKJgWjzN3Vj53KQ9fORqvkaN5Q@mail.gmail.com>


On 10/31/23 08:25, Corey Huinker wrote:
>
> Attached is v2 of this patch.
> 
> New features:
> * imports index statistics. This is not strictly accurate: it 
> re-computes index statistics the same as ANALYZE does, which is to
> say it derives those stats entirely from table column stats, which
> are imported, so in that sense we're getting index stats without
> touching the heap.

Maybe I just don't understand, but I'm pretty sure ANALYZE does not
derive index stats from column stats. It actually builds them from the
row sample.

> * now support extended statistics except for MCV, which is currently 
> serialized as an difficult-to-decompose bytea field.

Doesn't pg_mcv_list_items() already do all the heavy work?


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company






view thread (21+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Statistics Import and Export
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox