Re: Postgres Load Profile

Thank you, Laurenz!

On Mon, Nov 3, 2025 at 9:25 PM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
wrote:

> On Mon, 2025-11-03 at 14: 56 -0800, Sam Stearns wrote: > Does Postgres
> have any tables you can query to find out information such as: > * Logical
> reads > * Block changes > * Physical reads > * Physical writes > * Read
> IO
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> On Mon, 2025-11-03 at 14:56 -0800, Sam Stearns wrote:
> > Does Postgres have any tables you can query to find out information such as:
> > * Logical reads
> > * Block changes
> > * Physical reads
> > * Physical writes
> > * Read IO requests
> > * Write IO requests
> > * Read IO (MB)
> > * Write IO (MB)
> > * User calls
> > * Parses (SQL)
> > * Hard parses (SQL)
> > * Executes (SQL)
> > * Transactions per second
>
> That smells like Oracle database.
>
> PostgreSQL does things differently, so not all of the above measures make sense.
> To make up, there are things that you should measure in a PostgreSQL database
> that don't exist in an Oracle database.
>
> PostgreSQL doesn't do direct I/O, so it has no control over which read requests
> actually cause I/O to happen and which ones can be satisfied from the kernel
> page cache.
>
> You can find statistics about read and write activity in pg_stat_database
> (per database) and pg_stat_statements (per statement). pg_stat_statements will
> also tell you how often statements were executed.
>
> In PostgreSQL, statements are always planned, unless you explicitly use a
> prepared statement or run static SQL from a function.
>
> You might want to look at pg_stat_io for overall I/O statistics per operation
> and object type.
>
> You also should look at pg_stat_all_tables for activities per table, including
> the important VACUUM-related statistics.
>
> Yours,
> Laurenz Albe
>
>

--

Samuel Stearns
Team Lead - Database
c: 971 762 6879 | o: 971 762 6879 | DAT.com

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