7506508631
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CI / check (push) Failing after 6m14s
The schema's comment still called it the field last-write-wins compares. A write is decided by change_seq alone; updated_at is for display. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
48 lines
2.0 KiB
PL/PgSQL
48 lines
2.0 KiB
PL/PgSQL
-- Hankan sync schema.
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--
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-- Mirrors the client's syncable tables, plus the two columns the client does
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-- not have: change_seq, which the server assigns and clients use as a
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-- cursor, and user_id, which is one value today but keeps a second device or
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-- person from being a migration.
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--
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-- Rows are stored generically: the primary key as text, the row body as
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-- JSONB. The alternative — six typed tables kept in lockstep with the
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-- client's migrations — buys nothing here, because the server never reads
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-- inside a row. It stores and orders them; the client interprets them.
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CREATE TABLE IF NOT EXISTS sync_row (
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user_id TEXT NOT NULL,
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tbl TEXT NOT NULL,
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pk TEXT NOT NULL,
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data JSONB NOT NULL,
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-- The client's wall clock, when the row was last edited. Kept for display
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-- only: since protocol 2 (002-protocol-2.sql) nothing compares it — a
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-- write is decided by change_seq alone.
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updated_at BIGINT NOT NULL,
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-- A delete. Kept as a row so it can be handed to a device that was
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-- offline when it happened.
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deleted BOOLEAN NOT NULL DEFAULT FALSE,
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-- Server-assigned and monotonic. The cursor a client pages from.
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change_seq BIGSERIAL NOT NULL,
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PRIMARY KEY (user_id, tbl, pk)
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);
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-- The pull query is exactly this: everything newer than the client's cursor,
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-- in assignment order.
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CREATE INDEX IF NOT EXISTS sync_row_cursor ON sync_row (user_id, change_seq);
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-- change_seq must advance on every update, or a row edited after a client
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-- last pulled would sit below that client's cursor and never be delivered.
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-- Doing it in a trigger means no write path can forget.
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CREATE OR REPLACE FUNCTION sync_row_bump() RETURNS trigger AS $$
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BEGIN
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NEW.change_seq := nextval('sync_row_change_seq_seq');
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RETURN NEW;
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END;
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$$ LANGUAGE plpgsql;
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DROP TRIGGER IF EXISTS sync_row_bump_trg ON sync_row;
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CREATE TRIGGER sync_row_bump_trg
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BEFORE UPDATE ON sync_row
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FOR EACH ROW EXECUTE FUNCTION sync_row_bump();
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