16 lines
761 B
MySQL
16 lines
761 B
MySQL
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-- create a partial exclusion constraint that prevents insertion of duplicate items within 10 minutes
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CREATE EXTENSION IF NOT EXISTS btree_gist;
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ALTER TABLE "Item" ADD CONSTRAINT "Item_unique_time_constraint"
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EXCLUDE USING gist (
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"userId" WITH =,
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-- we use COALESCE so NULL is considered equal to itself. we also use md5 hashes because columns
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-- of type TEXT can make index row too large and columns of type CITEXT are not supported by GiST.
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COALESCE("parentId", -1) WITH =,
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md5(COALESCE("title", '')) WITH =,
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md5(COALESCE("subName", '')) WITH =,
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md5(COALESCE("text", '')) WITH =,
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tsrange(created_at, created_at + INTERVAL '10 minutes') WITH &&
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)
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-- enforce constraint after this date
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WHERE (created_at > '2024-12-30');
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