From: Ron <ronljohnsonjr@gmail.com>
To: pgsql-admin@lists.postgresql.org
Subject: Re: delete then insert
Date: Fri, 17 Jan 2020 15:20:25 -0600
Message-ID: <6557b021-04e9-4c1f-4661-8f063809211c@gmail.com> (raw)
In-Reply-To: <BN6PR19MB0081C5DFB5E0AD45BACD6838A3310@BN6PR19MB0081.namprd19.prod.outlook.com>
References: <BN6PR19MB00810F01715E27D5AE8D77D0A3310@BN6PR19MB0081.namprd19.prod.outlook.com>
<4e1f53ad-6793-c714-46bc-bc7d16b836b1@gmail.com>
<BN6PR19MB0081C5DFB5E0AD45BACD6838A3310@BN6PR19MB0081.namprd19.prod.outlook.com>
On 1/17/20 2:59 PM, Ken Benson wrote:
>
> *From:* Ron <ronljohnsonjr@gmail.com>
> *Sent:* Friday, January 17, 2020 12:12 PM
> *To:* pgsql-admin@lists.postgresql.org
> *Subject:* Re: delete then insert
>
> On 1/17/20 2:03 PM, Ken Benson wrote:
>
> So – I THINK I know – that when a row is deleted from a table – the
> row is not actually removed from the table – but, merely marked as
> deleted, thus becoming a dead tuple.
> AUTOVACUUM – takes care of the process of removing these dead tuples.
>
> My question. If – an insert occurs to that same table before
> autovacuum comes along, does that inserted record use a dead tuple? Or
> – does the insert result in an actual added row?
>
>
> If there's an open transaction which is still looking at the now-deleted
> record, then over-writing that area of the file would be a Bad Thing.
>
> */So – the answer is – NO – the dead tuple won’t be used until is has been
> reclaimed by vacuum – and that it doesn’t because it would be a bad thing,
> right?/*
>
I don't know what happens if not other transaction is holding that "slot".
--
Angular momentum makes the world go 'round.
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To: pgsql-admin@postgresql.org
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Subject: Re: delete then insert
In-Reply-To: <6557b021-04e9-4c1f-4661-8f063809211c@gmail.com>
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