postgresql分区表

摘要：创建自动分区采用两种方式采用视图分区方式采用直接分区方式创建表创建索引采用视图分区方式建立视图定义分表保证分区后的可以自增按照时间进行分区分表触发器定义更新更新触发器直接分区方式分表触发器两种方式比较视图分区所有操作都是对视图的操

创建自动分区采用两种方式

采用视图分区方式
采用直接分区方式

CREATE TABLE IF NOT EXISTS public.sales
(
    id bigserial primary key ,
    store_id varchar(50) ,
    business_date date,
    start_time time,
    end_time time,
    dine_in_tc int,
    delivery_tc int,
    takeout_tc int,
    dine_in_s decimal(20,4),
    delivery_s decimal(20,4),
    takeout_s decimal(20,4),
    voucher_overcharge decimal(20,4),
    freight decimal(20,4),
    currency varchar(16),
    created_at timestamp default now(),
    updated_at timestamp default now()
);

CREATE INDEX sales_store_id ON public.sales (store_id);
CREATE INDEX sales_business_date ON public.sales (business_date);
ALTER TABLE public.sales  ADD CONSTRAINT sales_storeid_businessdate_starttime_endtime UNIQUE(store_id,business_date,start_time,end_time);

CREATE VIEW public.sales_view AS SELECT * FROM public.sales;

CREATE OR REPLACE FUNCTION public.insert_sales() 
RETURNS TRIGGER AS
"."$BODY"."$
DECLARE
    _start_dt text;
    _end_dt text;
    _table_name text;
BEGIN     
IF NEW.id IS NULL THEN
NEW.id := nextval("sales_id_seq");    // 保证分区后的id可以自增
END IF;
_table_name := "sales_view_" || to_char(NEW.business_date, "YYYY_MM");    // 按照时间进行分区

PERFORM 1
FROM   pg_catalog.pg_class c
JOIN   pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE  c.relkind = "r"
AND    c.relname = _table_name
AND    n.nspname = public;
IF NOT FOUND THEN
    _start_dt := to_char(date_trunc("month", NEW.business_date), "YYYY-MM-DD");
    _end_dt:=_start_dt::timestamp + INTERVAL "1 month";
    EXECUTE 
    "CREATE TABLE public." 
    || quote_ident(_table_name) 
    || " (CHECK (business_date >= " 
    || quote_literal(_start_dt) 
    || "AND business_date < " 
    || quote_literal(_end_dt) 
    || ")) INHERITS (public.sales)";
    EXECUTE "CREATE INDEX " || quote_ident(_table_name||"_business_date"||_start_dt) || " ON public." || quote_ident(_table_name) || " (business_date)";
    EXECUTE "CREATE INDEX " || quote_ident(_table_name||"_store_id"||_start_dt) || " ON public." || quote_ident(_table_name) || " (store_id)";
    EXECUTE "ALTER TABLE public." || quote_ident(_table_name) || " ADD CONSTRAINT " || quote_ident(_table_name||"_storeid_businessdate_starttime_endtime"||_start_dt) || " UNIQUE (store_id,business_date,start_time,end_time)";
    EXECUTE "ALTER TABLE public." || quote_ident(_table_name) || " OWNER TO " || quote_ident(current_user);
    EXECUTE "GRANT ALL ON TABLE public." || quote_ident(_table_name) || " TO " || quote_ident(current_user);
END IF;
    EXECUTE "INSERT INTO public." || quote_ident(_table_name) || " VALUES ($1.*) RETURNING *" USING NEW;
    RETURN NEW;
END;
"."$BODY"."$
LANGUAGE plpgsql;
";

CREATE TRIGGER insert_sales_trigger INSTEAD OF INSERT ON public.sales_view FOR EACH ROW EXECUTE PROCEDURE insert_sales();

CREATE OR REPLACE FUNCTION update_sales()
RETURNS TRIGGER AS $$
BEGIN
    DELETE FROM sales_view WHERE id = NEW.id;
    INSERT INTO sales_view VALUES (NEW.*);
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;
";

CREATE TRIGGER update_sales_trigger INSTEAD OF UPDATE ON sales_view FOR EACH ROW EXECUTE PROCEDURE update_oc_sales();

CREATE OR REPLACE FUNCTION insert_sales() 
RETURNS TRIGGER AS
"."$BODY"."$
DECLARE
    _start_dt text;
    _end_dt text;
    _table_name text;
BEGIN     
IF NEW.id IS NULL THEN
    NEW.id := nextval("".$this->tableName."_id_seq");  
END IF;
_table_name := "sales_" || to_char(NEW.business_date, "YYYY_MM");
PERFORM 1
FROM   pg_catalog.pg_class c
JOIN   pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE  c.relkind = "r"
AND    c.relname = _table_name
AND    n.nspname = "public";
IF NOT FOUND THEN
    _start_dt := to_char(date_trunc("month", NEW.business_date), "YYYY-MM-DD");
    _end_dt:=_start_dt::timestamp + INTERVAL "1 month";
    EXECUTE 
    "CREATE TABLE IF NOT EXISTS public." 
    || quote_ident(_table_name) 
    || " (CHECK (business_date >= " 
    || quote_literal(_start_dt) 
    || "AND business_date < " 
    || quote_literal(_end_dt) 
    || ")) INHERITS (public.sales)";
    EXECUTE "CREATE INDEX IF NOT EXISTS" || quote_ident(_table_name||"_business_date"||_start_dt) || " ON public." || quote_ident(_table_name) || " (business_date)";
    EXECUTE "CREATE INDEX IF NOT EXISTS" || quote_ident(_table_name||"_store_id"||_start_dt) || " ON public." || quote_ident(_table_name) || " (store_id)";
    EXECUTE "CREATE UNIQUE INDEX IF NOT EXISTS" || quote_ident(_table_name||"_storeid_businessdate_starttime_endtime"||_start_dt) || " ON public." || quote_ident(_table_name) || " (store_id,business_date,start_time,end_time)";
    EXECUTE "ALTER TABLE public." || quote_ident(_table_name) || " OWNER TO " || quote_ident(current_user);
    EXECUTE "GRANT ALL ON TABLE public." || quote_ident(_table_name) || " TO " || quote_ident(current_user);
END IF;
    EXECUTE "INSERT INTO public." || quote_ident(_table_name) || " VALUES ($1.*) on conflict(store_id,business_date,start_time,end_time) do nothing RETURNING *" USING NEW;
    RETURN NULL;
END;
"."$BODY"."$
LANGUAGE plpgsql;

CREATE TRIGGER insert_sales_trigger BEFORE INSERT ON public.salses FOR EACH ROW EXECUTE PROCEDURE insert_sales();

视图分区所有操作都是对视图的操作，直接分区是对主表进行操作；

视图分区触发器使用instead of,直接分区使用before,因为无法直接用触发器替代对主表的操作，只能操作视图；

视图分区用instead of，在function中可以RETURN NEW，对数据库操作后有明确的返回，直接分区用before方式，在function中采用RETURN NULL,数据库操作没有返回；

直接分区可以用on conflict对主表insert进行ignore操作，视图分区不能。