Update SQL statements in docs for Synapse Admins

[dklimpel]

Fixes: #12525

• reformat queries with https://www.freeformatter.com/sql-formatter.html
• replace use of user_stats_historical
• replace use of role synapse with username and passwort with psql and add link to psql docs
  • add query to get same information with native sql

Pull Request Checklist

• Pull request is based on the develop branch
• Pull request includes a changelog file. The entry should:
  • Be a short description of your change which makes sense to users. "Fixed a bug that prevented receiving messages from other servers." instead of "Moved X method from EventStore to EventWorkerStore.".
  • Use markdown where necessary, mostly for code blocks.
  • End with either a period (.) or an exclamation mark (!).
  • Start with a capital letter.
  • Feel free to credit yourself, by adding a sentence "Contributed by @github_username." or "Contributed by [Your Name]." to the end of the entry.
• Pull request includes a sign off
• Code style is correct
  (run the linters)

Signed-off-by: Dirk Klimpel mailto:dirk@klimpel.org

[clokep]

This has the potential to be very slow, I think?

[dklimpel]

Is there a chance for another solution / query? Or should I am add a warning?

[clokep]

I think just adding a warning about it would be enough.

[dklimpel]

synapse=> explain SELECT
synapse->   COUNT(*),
synapse->   sender 
synapse-> FROM
synapse->   events 
synapse-> WHERE
synapse->   (
synapse(>     type = 'm.room.encrypted' 
synapse(>     OR type = 'm.room.message'
synapse(>   )
synapse->   AND origin_server_ts >= DATE_PART('epoch', NOW() - INTERVAL '1 month') * 1000 
synapse-> GROUP BY
synapse->   sender 
synapse-> ORDER BY
synapse->   COUNT(*) DESC LIMIT 20;
                                                                                                              QUERY PLAN                                                                                                               
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=2077.77..2077.82 rows=20 width=64)
   ->  Sort  (cost=2077.77..2083.53 rows=2303 width=64)
         Sort Key: (count(*)) DESC
         ->  HashAggregate  (cost=1993.46..2016.49 rows=2303 width=64)
               Group Key: sender
               ->  Seq Scan on events  (cost=0.00..1975.47 rows=3598 width=56)
                     Filter: (((type = 'm.room.encrypted'::text) OR (type = 'm.room.message'::text)) AND ((origin_server_ts)::double precision >= (date_part('epoch'::text, (now() - '1 mon'::interval)) * '1000'::double precision)))
(7 rows)

[clokep]

This is a bit scary that we document these SQL statements instead of adding APIs! Can any of these be removed and use the admin API instead?

I wonder if this should at least point to the admin API...

[DMRobertson]

For what it's worth, I think all the queries here are SELECTs. Though as you say elsewhere, an expensive SELECT can still cause pain!

[squahtx]

I'm not 100% sold on the choice of formatter. In my (admittedly personal) opinion, it makes the SQL harder to read.
Sorry to be difficult, but is there any chance we can stick to the old style for now, and split out the formatting changes into a separate PR?

[dklimpel]

I have revert the SQL format to the old style.

[H-Shay]

Issue to track adding these queries to the Admin API: #12682