47 lines
1.8 KiB
SQL
47 lines
1.8 KiB
SQL
-- M7 #352 slice 2: system-generated playlists.
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-- Adds kind/system_variant/seed_artist_id columns to playlists and a
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-- per-user run-tracking table. Backfills existing slice-1 playlists
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-- to kind='user'.
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-- Discriminator on existing playlists table.
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ALTER TABLE playlists
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ADD COLUMN kind text NOT NULL DEFAULT 'user',
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ADD COLUMN system_variant text,
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ADD COLUMN seed_artist_id uuid REFERENCES artists(id) ON DELETE SET NULL;
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-- Belt-and-braces backfill in case the DEFAULT didn't apply on some
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-- runtime branches; a no-op when the column metadata already filled.
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UPDATE playlists SET kind = 'user' WHERE kind IS NULL OR kind = '';
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-- Constraint: kind/system_variant pair is consistent.
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ALTER TABLE playlists
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ADD CONSTRAINT playlists_kind_variant_consistent
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CHECK (
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(kind = 'user' AND system_variant IS NULL)
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OR
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(kind = 'system' AND system_variant IN ('for_you', 'songs_like_artist'))
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);
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-- Constraint: 'songs_like_artist' has a seed artist; nothing else does.
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ALTER TABLE playlists
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ADD CONSTRAINT playlists_seed_consistent
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CHECK (
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(system_variant IS NULL AND seed_artist_id IS NULL)
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OR
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(system_variant = 'for_you' AND seed_artist_id IS NULL)
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OR
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(system_variant = 'songs_like_artist' AND seed_artist_id IS NOT NULL)
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);
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-- Filter index for kind=user vs kind=system queries on the user's row.
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CREATE INDEX playlists_user_kind_idx ON playlists (user_id, kind);
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-- Per-user run tracking — one row per user.
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CREATE TABLE system_playlist_runs (
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user_id uuid PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
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last_run_at timestamptz,
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last_run_date date,
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in_flight boolean NOT NULL DEFAULT false,
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last_error text
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);
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