全局临时表函数

• pg_get_gtt_relstats(relOid)

  描述：显示当前会话指定的全局临时表的基本信息。

  参数：全局临时表的OID。

  返回值类型：record

  示例:

  postgres=# select * from pg_get_gtt_relstats(74069);
   relfilenode | relpages | reltuples | relallvisible | relfrozenxid | relminmxid 
  -------------+----------+-----------+---------------+--------------+------------
         74069 |       58 |     13000 |             0 |        11151 |          0
  (1 row)

• pg_get_gtt_statistics(relOid, attnum, “::text)

  描述：显示当前会话指定的全局临时表的单列统计信息。

  参数：全局临时表的OID和属性attnum。

  返回值类型：record

  示例:

  postgres=# select * from pg_get_gtt_statistics(74069,1,''::text);
   starelid | starelkind | staattnum | stainherit | stanullfrac | stawidth | stadistinct | stakind1 | stakind2 | stakind3 | stakind4 | stakind5 | staop1 | staop2 | staop3 | staop4 | staop5 | stanumbers1 | stanumbers2 | stanumbers3 | stanu
  mbers4 | stanumbers5 |                                                                                                                                                                                                                      
                                            stavalues1                                                                                                                                                                                        
                                                                          | stavalues2 | stavalues3 | stavalues4 | stavalues5 | stadndistinct | staextinfo 
  ----------+------------+-----------+------------+-------------+----------+-------------+----------+----------+----------+----------+----------+--------+--------+--------+--------+--------+-------------+-------------+-------------+------
  -------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  ------------------------------------------------------------------------+------------+------------+------------+------------+---------------+------------
      74069 | c          |         1 | f          |           0 |        4 |          -1 |        2 |        3 |        0 |        0 |        0 |     97 |     97 |      0 |      0 |      0 |             | {1}         |             |      
         |             | {1,130,260,390,520,650,780,910,1040,1170,1300,1430,1560,1690,1820,1950,2080,2210,2340,2470,2600,2730,2860,2990,3120,3250,3380,3510,3640,3770,3900,4030,4160,4290,4420,4550,4680,4810,4940,5070,5200,5330,5460,5590,57
  20,5850,5980,6110,6240,6370,6500,6630,6760,6890,7020,7150,7280,7410,7540,7670,7800,7930,8060,8190,8320,8450,8580,8710,8840,8970,9100,9230,9360,9490,9620,9750,9880,10010,10140,10270,10400,10530,10660,10790,10920,11050,11180,11310,11440,1
  1570,11700,11830,11960,12090,12220,12350,12480,12610,12740,12870,13000} |            |            |            |            |             0 | 
  (1 row)

• pg_gtt_attached_pid(relOid)

  描述：显示正在使用指定全局临时表的所有线程pid。

  参数：全局临时表的OID。

  返回值类型：record

  示例:

  postgres=# select * from pg_gtt_attached_pid(74069);
   relid |       pid       
  -------+-----------------
   74069 | 139648170456832
   74069 | 139648123270912
  (2 rows)

• pg_list_gtt_relfrozenxids()

  描述：显示各会话的冻结事务xid。

  pid=0的行，显示所有会话中最老的冻结事务xid。

  参数：无。

  返回值类型：record

  示例:

  postgres=# select * from pg_list_gtt_relfrozenxids();
         pid       | relfrozenxid 
  -----------------+--------------
   139648123270912 |        11151
   139648170456832 |        11155
                 0 |        11151
  (3 rows)