【有用的SQL】查Greenplum的数据字典

Greenplum

1. 查询哪个表的分布键 ( Greenplum )

   SELECT
       att.nspname AS 模式名
     ,	att.relname AS 表名
     ,	table_comment AS 表注释
     ,	string_agg (a.attname, '、') AS 分布键
       FROM
       (
        SELECT c.oid
           , obj_description(c.oid) AS table_comment
           , n.nspname,c.relname,regexp_split_to_table (array_to_string (d.distkey, ' '),' ')::int as attnu
        FROM gp_distribution_policy d
        LEFT JOIN pg_class c ON c.oid = d.localoid
        LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
        WHERE c.oid = 'u_dws.opn_label_factory_user_group'::regclass -- '模式名.表名'::regclass
       ) att
       LEFT JOIN pg_attribute a ON a.attrelid = att.oid
       WHERE att.attnu = a.attnum
       GROUP BY 1,2,3
     ;
   

   或者是：

   SELECT
       aaa.oid,
       aaa.nspname AS "模式名",
       aaa.relname AS "表名",
       aaa.table_comment AS "中文表名",
       ccc.attname AS "分布键"
   FROM
       (
   SELECT
       aa.oid,
       aa.relname,
       obj_description ( aa.oid ) AS table_comment,
       bb.localoid,
       bb.distkey,
       regexp_split_to_table( array_to_string( bb.distkey, ' ' ), ' ' ) att,
       dd.nspname
   FROM
       pg_class aa
       LEFT JOIN pg_catalog.gp_distribution_policy bb ON bb.localoid = aa.oid
       LEFT JOIN pg_namespace dd ON dd.oid = aa.relnamespace --模式
       LEFT JOIN pg_inherits hh ON aa.oid = hh.inhrelid --继承表
   WHERE
       dd.nspname = 'u_dws_dev' -- 替换成需要的模式schema
       AND hh.inhrelid IS NULL
       ) aaa
       LEFT JOIN pg_attribute ccc ON ccc.attrelid = aaa.oid
       AND CAST ( ccc.attnum AS TEXT ) = aaa.att
   WHERE
       ccc.attnum > 0
   AND aaa.relname = 'opn_label_factory_user_group' --需要查询的表名
   ;
   

2. 查看每个表的表注释 ( Greenplum )

     -- 直接执行就可以
     with tmp_tab as (
         select pc.oid as ooid,pn.nspname,pc.*
           from pg_class pc
                left outer join pg_namespace pn
                             on pc.relnamespace = pn.oid
           where 1=1
            and pc.relkind in ('r')
            and pn.nspname not in ('pg_catalog','information_schema') -- select pn.oid, pn.* from pg_namespace pn where 1=1
            and pn.nspname not like 'pg_toast%'
            and pc.oid not in (
               select inhrelid
                 from pg_inherits
            )
            and pc.relname not like '%peiyb%'
         order by pc.relname
     ),tmp_desc as (
        select pd.*
          from pg_description pd
         where 1=1
           and pd.objsubid = 0 --objsubid 对于一个表列上的一个注释，这里是列号（objoid和classoid指表本身）。对所有其他对象类型，此列为0。
           --and pd.objoid=168605
     )
     select t0.*
       from (
             select tab.relname as table_name, -- tab.relname：表名
                    de.description -- de.description：表注释
               from tmp_tab tab
                    left outer join tmp_desc de
                                 on tab.ooid = de.objoid
              where 1=1 and tab.nspname = 'ods_rk' -- and tab.relname='your_table_name' -- tab.nspname：模式名
             ) t0
      where 1=1;
   

3. 通过MYSQL为Greenplum加注释

• 加表注释

   select
   CONCAT('COMMENT ON TABLE "edc_rk"."', a.TABLE_NAME, '" IS ''', a.TABLE_COMMENT, ''';') AS `SQL`
   from information_schema.TABLES a
   where a.TABLE_SCHEMA = 'edc_rk' and a.TABLE_NAME not like '%copy%'
   ORDER BY a.TABLE_NAME
   ;
  

• 加列注释

  select
  b.ORDINAL_POSITION AS 列序号
  , CONCAT('COMMENT ON COLUMN "edc_rk"."', a.TABLE_NAME, '"."', b.COLUMN_NAME, '" IS ''', b.COLUMN_COMMENT,  ''';') AS `SQL`
  from information_schema.TABLES a left join information_schema.COLUMNS b
  on a.TABLE_SCHEMA = 'edc_rk'-- and SUBSTR(a.TABLE_COMMENT, 1, 1) = '|'
  and a.TABLE_SCHEMA = b.TABLE_SCHEMA and a.TABLE_NAME = b.TABLE_NAME
  where a.TABLE_SCHEMA = 'edc_rk' and a.TABLE_NAME not like '%copy%' and a.TABLE_NAME <> 'sheet1'
  ORDER BY a.TABLE_NAME, b.ORDINAL_POSITION
  ;
  

1. 查询字段的注释等相关信息

   SELECT UPPER(A.SCHEMANAME) AS SCHEMANAME,
          UPPER(A.TABLENAME) AS TABLENAME,
          --D.ATTRELID ,
          --D.ATTRELID::regclass,
          UPPER(D.ATTNAME) AS ATTNAME,
          REPLACE(REPLACE(REPLACE(FORMAT_TYPE(D.ATTTYPID, D.ATTTYPMOD),
                                  'numeric',
                                  'NUMBER'),
                          'character varying',
                          'VARCHAR2'),
                  'date',
                  'DATE') AS DATA_TYPE,
          E.DESCRIPTION
     FROM PG_TABLES A
    INNER JOIN PG_CLASS B
       ON A.TABLENAME = B.RELNAME
     LEFT JOIN PG_CATALOG.PG_DESCRIPTION E
       ON B.OID = E.OBJOID
     LEFT JOIN PG_CATALOG.PG_ATTRIBUTE D
       ON D.ATTRELID = E.OBJOID
      AND D.ATTNUM = E.OBJSUBID
    WHERE SCHEMANAME = 'pmart_risk'
      AND A.TABLENAME LIKE '%表名称%'
      AND D.ATTNUM > 0
     ORDER BY A.TABLENAME ,D.ATTNUM
   ;