Horton

Re: pg_stat_progress_basebackup - progress reporting for pg_basebackup, in the server side

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Amit Langote <amitlangote09@gmail.com>
Cc: Fujii Masao <masao.fujii@oss.nttdata.com>, Magnus Hagander <magnus@hagander.net>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, "Shinoda, Noriyoshi (PN Japan A&PS Delivery)" <noriyoshi.shinoda@hpe.com>, Masahiko Sawada <masahiko.sawada@2ndquadrant.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2020-03-19T02:24:26Z
Lists: pgsql-hackers 
On 2020-Mar-19, Amit Langote wrote:

> Magnus' idea of checking the values in pg_stat_get_progress_info() to
> determine whether to return NULL seems fine to me.  We will need to
> update the documentation of st_progress_param, because it currently
> says:
> 
>      *  ...but the meaning of each element in the
>      * st_progress_param array is command-specific.
>      */
>     ProgressCommandType st_progress_command;
>     Oid         st_progress_command_target;
>     int64       st_progress_param[PGSTAT_NUM_PROGRESS_PARAM];
> } PgBackendStatus;
> 
> If we are to define -1 in st_progress_param[] as NULL to the users,
> that must be mentioned here.

Hmm, why -1?  It seems like a value that we might want to use for other
purposes in other params.  Maybe INT64_MIN is a better choice?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Report NULL as total backup size if it's not estimated.

  2. Make pg_basebackup ask the server to estimate the total backup size, by default.

  3. Report progress of streaming base backup.