006.PGSQL-資料傾斜、資料各節點分佈情況；建立序列、建立分散式表

阿新 • • 發佈：2020-08-03

資料傾斜、資料各節點分佈情況、建立分散式表

查看錶的分佈節點

-- 查看錶是否資料傾斜
select table_skewness('b_st_yz_aj_cgajfj');

-- 在哪個節點分佈

-- 查看錶是否資料傾斜 
select table_skewness('b_st_yz_aj_cgajfj');
 
 -- 在哪個節點分佈
select 
xc_node_id, count(1) 
from tablename 
group by xc_node_id 
order by xc_node_id desc;

建立序列、建立分散式表

建立序列

CREATE SEQUENCE "ioc_theme"."m_ss_qyqy_move_warn_success_rid_seq" 
INCREMENT  
1
MINVALUE  1
MAXVALUE 9223372036854775807
START 1
CACHE 1
CYCLE ;

SELECT setval('"ioc_theme"."m_ss_qyqy_move_warn_success_rid_seq"', -1, false);

ALTER SEQUENCE "ioc_theme"."m_ss_qyqy_move_warn_success_rid_seq" OWNER TO "zsj_qh";

刪除序列修改序列

----刪除前先解除 id 對該序列的依賴
ALTER TABLE tablename ALTER COLUMN id SET 
 DEFAULT null;
DROP SEQUENCE IF EXISTS sequence_name;

修改自增序列開始值
---- id_max 即 id 目前的最大值，可寫為1，可通過 “SELECT MAX(id) FROM tablename” 得到

CREATE SEQUENCE sequence_name START WITH id_max;
修改自增序列所屬的表和欄位
ALTER TABLE ioc_theme.m_ss_yqjc_sbryxxb_51_af ALTER COLUMN rid SET DEFAULT nextval('ioc_theme.m_ss_yqjc_sbryxxb_51_af_rid_seq 
'::regclass);

查詢表的序列

select table_schema, 
       table_name,
       column_name,
       data_type,
       column_default,
       is_nullable
  from information_schema.columns
 where table_name = 'm_gd_yqjc_sbryxxb_0501_0520';

建立分散式表

CREATE TABLE "ioc_theme"."m_hz_cyrk_rk_education" (
  "rid" int4 NOT NULL DEFAULT nextval('"ioc_theme".m_hz_cyrk_rk_education_rid_seq'::regclass),
  "occur_period" int4,
  "occur_period_year" int4,
  "occur_period_month" int4,
  "area_code_abode" varchar(20) COLLATE "pg_catalog"."default",
  "area_code_work" varchar(20) COLLATE "pg_catalog"."default",
  "degree" varchar(40) COLLATE "pg_catalog"."default",
  "employ_num" int4,
  "employ_ratio" numeric(20,2),
  "create_time" timestamp(6) DEFAULT pg_systimestamp(),
  "update_time" timestamp(6) DEFAULT pg_systimestamp(),
  CONSTRAINT "m_hz_cyrk_rk_education_pkey" PRIMARY KEY ("rid")
)
;

ALTER TABLE "ioc_theme"."m_hz_cyrk_rk_education" 
  OWNER TO "zsj_qh";

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."rid" IS '行ID';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."occur_period" IS '報告期';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."occur_period_year" IS '報告期(年)';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."occur_period_month" IS '報告期(月)';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."area_code_abode" IS '居住地行政區劃程式碼（社群）';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."area_code_work" IS '工作地行政區劃程式碼';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."degree" IS '學歷';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."employ_num" IS '人數';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."employ_ratio" IS '佔比';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."create_time" IS '資料建立時間';

COMMENT ON COLUMN "ioc_theme"."m_hz_cyrk_rk_education"."update_time" IS '更新時間';

COMMENT ON TABLE "ioc_theme"."m_hz_cyrk_rk_education" IS '人才專題介面';