From: Vasilis Ventirozos <v.ventirozos@gmail.com>
To: Hans Braxmeier <hans.braxmeier@outlook.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: Restoring a table is ten times slower on Ubuntu 14.04 than on Ubuntu 16.04
Date: Tue, 2 Jan 2018 15:30:17 +0200
Message-ID: <39C0ED47-99F1-4433-9645-48F25739836C@gmail.com> (raw)
In-Reply-To: <VI1PR0402MB393624C592AB5106DC92A92499190@VI1PR0402MB3936.eurprd04.prod.outlook.com>
References: <VI1PR0402MB393624C592AB5106DC92A92499190@VI1PR0402MB3936.eurprd04.prod.outlook.com>
You are not providing too much info, its unclear to me whats actually slow.
If you can, try loading the data first and then create the indexes / constraints. that should be faster.
> On 2 Jan 2018, at 15:27, Hans Braxmeier <hans.braxmeier@outlook.com> wrote:
>
> Hi,
>
> I try to restore a table on U16.04, but it's ten times slower than on U14.04. This is the definition of the table:
>
> testdb=# \d photos_searchlog
>
> Table "public.photos_searchlog"
> Column | Type | Collation | Nullable | Default
> ----------+--------------------------+-----------+----------+----------------------------------------------
> id | integer | | not null | nextval('photos_searchlog_id_seq'::regclass)
> created | timestamp with time zone | | not null |
> updated | timestamp with time zone | | not null |
> lang | character varying(2) | | not null |
> q | character varying(255) | | not null |
> hits | integer | | not null |
> count | integer | | not null |
> ip_list | text | | not null |
> locked | boolean | | not null |
> ts_list | text | | not null |
> ts_count | integer | | not null |
> Indexes:
> "photos_searchlog_pkey" PRIMARY KEY, btree (id)
> "photos_searchlog_lang_q_key" UNIQUE CONSTRAINT, btree (lang, q)
> "photos_searchlog_count" btree (count)
> "photos_searchlog_created" btree (created)
> "photos_searchlog_ts_count" btree (ts_count)
> "photos_searchlog_updated" btree (updated)
>
> It's only the statement ALTER TABLE ONLY photos_searchlog ADD CONSTRAINT photos_searchlog_lang_q_key UNIQUE (lang, q); which causes the delay. I use the default postgres configuration on the same hardware (/etc/postgresql/10/main/postgresql.conf). I tested different postgres versions, checked the locale and other settings but can not find any differences. I also tried with more or less data, but always the same result.
>
> Does anybody have a clue what could cause the time difference?
>
> Thanks
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To: pgsql-performance@postgresql.org
Cc: v.ventirozos@gmail.com, hans.braxmeier@outlook.com
Subject: Re: Restoring a table is ten times slower on Ubuntu 14.04 than on Ubuntu 16.04
In-Reply-To: <39C0ED47-99F1-4433-9645-48F25739836C@gmail.com>
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