39 lines
1.3 KiB
SQL
39 lines
1.3 KiB
SQL
-- 一条 durable user update 只能有一个在线投递任务。历史 schema 的
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-- ON CONFLICT DO NOTHING 没有对应唯一键，先显式保留最早任务并删除重复项。
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WITH duplicates AS (
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SELECT id
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FROM (
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SELECT
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id,
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row_number() OVER (
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PARTITION BY target_user_id, pts
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-- 若历史重复中仍有可投递任务，优先保留它；不能让一个更早的
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-- failed 副本覆盖健康 pending 副本并人为阻塞该用户 lane。
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ORDER BY
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CASE status
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WHEN 'pending' THEN 0
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WHEN 'dispatching' THEN 1
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ELSE 2
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END,
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id ASC
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) AS rn
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FROM dispatch_outbox
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) ranked
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WHERE ranked.rn > 1
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)
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DELETE FROM dispatch_outbox d
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USING duplicates x
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WHERE d.id = x.id;
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CREATE UNIQUE INDEX dispatch_outbox_user_pts_uidx
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ON dispatch_outbox (target_user_id, pts);
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-- ClaimDispatchOutboxShards 固定用 256 logical shards；表达式必须与查询
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-- 完全一致，避免每个 worker 为筛自己的 lane 全表扫描。
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CREATE INDEX dispatch_outbox_logical_shard_head_idx
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ON dispatch_outbox (
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mod(target_user_id, 256::bigint),
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target_user_id,
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pts,
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id
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);
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