8e5defe6ca
This value is currently only used by Prometheus metrics but (after optimisng the peer query inthe preceeding commit) the most costly part of instance stats.
38 lines
1,008 B
Elixir
38 lines
1,008 B
Elixir
# Akkoma: Magically expressive social media
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# Copyright © 2024 Akkoma Authors <https://akkoma.dev/>
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# SPDX-License-Identifier: AGPL-3.0-only
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defmodule Pleroma.Repo.Migrations.RemoteUserCountEstimateFunction do
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use Ecto.Migration
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@function_name "estimate_remote_user_count"
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def up() do
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# yep, this EXPLAIN (ab)use is blessed by the PostgreSQL wiki:
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# https://wiki.postgresql.org/wiki/Count_estimate
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"""
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CREATE OR REPLACE FUNCTION #{@function_name}()
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RETURNS integer
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LANGUAGE plpgsql AS $$
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DECLARE plan jsonb;
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BEGIN
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EXECUTE '
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EXPLAIN (FORMAT JSON)
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SELECT *
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FROM public.users
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WHERE local = false AND
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is_active = true AND
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invisible = false AND
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nickname IS NOT NULL;
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' INTO plan;
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RETURN plan->0->'Plan'->'Plan Rows';
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END;
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$$;
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"""
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|> execute()
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end
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def down() do
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execute("DROP FUNCTION IF EXISTS #{@function_name}()")
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end
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end
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