openGauss gsql 常用元命令_gsql命令_胡正策的博客

连接数据库使用 -E参数可以显示元命令具体执行的SQL信息

[omm@og1 ~]$ gsql -d postgres -p15400 -E
gsql ((openGauss 2.1.0 build 590b0f8e) compiled at 2021-09-30 14:29:04 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
\l 显示数据库中数据库信息
 
openGauss=# \l
********* QUERY **********
SELECT d.datname as "Name",
       pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
       pg_catalog.pg_encoding_to_char(d.encoding) as "Encoding",
       d.datcollate as "Collate",
       d.datctype as "Ctype",
       pg_catalog.array_to_string(d.datacl, E'\n') AS "Access privileges"
FROM pg_catalog.pg_database d
ORDER BY 1;
**************************
                             List of databases
   Name    | Owner | Encoding |  Collate   |   Ctype    | Access privileges 
-----------+-------+----------+------------+------------+-------------------
 mydb      | omm   | UTF8     | en_US.utf8 | en_US.utf8 | 
 postgres  | omm   | UTF8     | en_US.utf8 | en_US.utf8 | 
 studentdb | omm   | UTF8     | en_US.utf8 | en_US.utf8 | 
 template0 | omm   | UTF8     | en_US.utf8 | en_US.utf8 | =c/omm           +
           |       |          |            |            | omm=CTc/omm
 template1 | omm   | UTF8     | en_US.utf8 | en_US.utf8 | =c/omm           +
           |       |          |            |            | omm=CTc/omm
(5 rows)
\du 同\dg 显示数据库中所有用户和角色
 
openGauss=# \du
********* QUERY **********
SELECT r.rolname, r.rolsuper, r.rolinherit,
  r.rolcreaterole, r.rolcreatedb, r.rolcanlogin,
  r.rolconnlimit, r.rolvalidbegin, r.rolvaliduntil,
  ARRAY(SELECT b.rolname
        FROM pg_catalog.pg_auth_members m
        JOIN pg_catalog.pg_roles b ON (m.roleid = b.oid)
        WHERE m.member = r.oid) as memberof
, r.rolreplication
, r.rolauditadmin
, r.rolsystemadmin
, r.rolmonitoradmin
, r.roloperatoradmin
, r.rolpolicyadmin
, r.roluseft
, r.rolkind
FROM pg_catalog.pg_roles r
WHERE r.rolname not in ('gs_role_copy_files', 'gs_role_signal_backend', 'gs_role_tablespace', 'gs_role_replication', 'gs_role_account_lock', 'gs_role_pldebugger')
ORDER BY 1;
**************************
                                                              List of roles
 Role name |                                                    Attributes                                                    | Member of 
-----------+------------------------------------------------------------------------------------------------------------------+-----------
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
 student   | Sysadmin                                                                                                         | {}
openGauss=# \dg
********* QUERY **********
SELECT r.rolname, r.rolsuper, r.rolinherit,
  r.rolcreaterole, r.rolcreatedb, r.rolcanlogin,
  r.rolconnlimit, r.rolvalidbegin, r.rolvaliduntil,
  ARRAY(SELECT b.rolname
        FROM pg_catalog.pg_auth_members m
        JOIN pg_catalog.pg_roles b ON (m.roleid = b.oid)
        WHERE m.member = r.oid) as memberof
, r.rolreplication
, r.rolauditadmin
, r.rolsystemadmin
, r.rolmonitoradmin
, r.roloperatoradmin
, r.rolpolicyadmin
, r.roluseft
, r.rolkind
FROM pg_catalog.pg_roles r
WHERE r.rolname not in ('gs_role_copy_files', 'gs_role_signal_backend', 'gs_role_tablespace', 'gs_role_replication', 'gs_role_account_lock', 'gs_role_pldebugger')
ORDER BY 1;
**************************
                                                              List of roles
 Role name |                                                    Attributes                                                    | Member of 
-----------+------------------------------------------------------------------------------------------------------------------+-----------
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
 student   | Sysadmin                                                                                                         | {}
\db 显示数据库中所有表空间信息
 
openGauss=# \db
********* QUERY **********
SELECT spcname AS "Name",
  pg_catalog.pg_get_userbyid(spcowner) AS "Owner",
  pg_catalog.pg_tablespace_location(oid) AS "Location"
FROM pg_catalog.pg_tablespace
ORDER BY 1;
**************************
             List of tablespaces
    Name    | Owner |        Location        
------------+-------+------------------------
 pg_default | omm   | 
 pg_global  | omm   | 
 student_ts | omm   | tablespace/student_ts1
(3 rows)
\dn 显示数据库中所有schema信息
 
openGauss=# \dn
********* QUERY **********
SELECT n.nspname AS "Name",
  pg_catalog.pg_get_userbyid(n.nspowner) AS "Owner"
FROM pg_catalog.pg_namespace n
WHERE n.nspname !~ '^pg_' AND n.nspname <> 'information_schema'
ORDER BY 1;
**************************
     List of schemas
      Name      |  Owner  
----------------+---------
 blockchain     | omm
 cstore         | omm
 db4ai          | omm
 dbe_perf       | omm
 dbe_pldebugger | omm
 pkg_service    | omm
 pmk            | omm
 public         | omm
 snapshot       | omm
 sqladvisor     | omm
 student        | student
(11 rows)
\d 显示当前数据库下相关数据库对象信息(包含表、视图、物化视图、序列、外部表、stream\ contview)
 
openGauss=# \d
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r','v','m','S','f','e','o','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
                         List of relations
 Schema |  Name  | Type  | Owner |             Storage              
--------+--------+-------+-------+----------------------------------
 public | test   | table | omm   | {orientation=row,compression=no}
 public | v_test | view  | omm   | 
(2 rows)
\d tablename 查看某个表的详细信息
 
openGauss=# \d test
********* QUERY **********
SELECT c.oid,
  n.nspname,
  c.relname
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relname ~ '^(test)$'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 2, 3;
**************************
********* QUERY **********
SELECT c.relchecks, c.relkind, c.relhasindex, c.relhasrules, c.relhastriggers, c.relhasoids, '', c.reltablespace, CASE WHEN c.reloftype = 0 THEN '' ELSE c.reloftype::pg_catalog.regtype::pg_catalog.text END, c.relpersistence,c.relhasclusterkey, c.relreplident, (select count(1) as haspolicy from pg_catalog.pg_class WHERE relname = 'pg_rlspolicy')
FROM pg_catalog.pg_class c
 LEFT JOIN pg_catalog.pg_class tc ON (c.reltoastrelid = tc.oid)
WHERE c.oid = '16575';
**************************
********* QUERY **********
SELECT * FROM pg_catalog.pg_class WHERE relname = 'gs_encrypted_columns' AND relnamespace = 11;
**************************
********* QUERY **********
SELECT a.attname,
  pg_catalog.format_type(a.atttypid, a.atttypmod),
  (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 176)
   FROM pg_catalog.pg_attrdef d
   WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef),
  a.attnotnull, a.attnum,
  (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type t
   WHERE c.oid = a.attcollation AND t.oid = a.atttypid AND a.attcollation <> t.typcollation) AS attcollation,
  NULL AS indexdef,
  NULL AS attfdwoptions,
 (SELECT pg_catalog.format_type (a.atttypmod, g.data_type_original_mod) AS clientlogic_original_type FROM  gs_encrypted_columns g WHERE g.column_name = a.attname  AND g.rel_id = 16575group by g.data_type_original_oid, g.data_type_original_mod),
(SELECT g.data_type_original_oid AS clientlogic_original_type_oid FROM  gs_encrypted_columns g WHERE g.column_name = a.attname  AND g.rel_id = 16575group by g.data_type_original_oid, g.data_type_original_mod),
 (SELECT  h.adgencol
   FROM pg_catalog.pg_attrdef h
   WHERE h.adrelid = a.attrelid AND h.adnum = a.attnum AND a.atthasdef) AS generated_column
FROM pg_catalog.pg_attribute a
WHERE a.attrelid = '16575' AND a.attnum > 0 AND NOT a.attisdropped AND a.attkvtype != 4 AND a.attname <> 'tableoid' AND a.attname <> 'tablebucketid'
ORDER BY a.attnum;
**************************
********* QUERY **********
SELECT c2.relname, i.indisprimary, i.indisunique, i.indisclustered, i.indisvalid, pg_catalog.pg_get_indexdef(i.indexrelid, 0, true),
  pg_catalog.pg_get_constraintdef(con.oid, true), contype, condeferrable, condeferred, i.indisreplident, c2.reltablespace, i.indisusable
FROM pg_catalog.pg_class c, pg_catalog.pg_class c2, pg_catalog.pg_index i
  LEFT JOIN pg_catalog.pg_constraint con ON (conrelid = i.indrelid AND conindid = i.indexrelid AND contype IN ('p','u','x'))
WHERE c.oid = '16575' AND c.oid = i.indrelid AND i.indexrelid = c2.oid
ORDER BY i.indisprimary DESC, i.indisunique DESC, c2.relname;
**************************
********* QUERY **********
SELECT pol.policyname, pol.policypermissive, trim(pol.policyroles::text, '{}'), pol.policyqual, pol.policycmd
FROM pg_catalog.pg_rlspolicies pol
LEFT JOIN pg_catalog.pg_namespace N on (N.nspname = pol.schemaname)
LEFT JOIN pg_catalog.pg_class C on (pol.tablename = C.relname and C.relnamespace = N.oid)
WHERE C.oid = '16575' ORDER BY 1;
**************************
********* QUERY **********
SELECT c.oid::pg_catalog.regclass FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i WHERE c.oid=i.inhparent AND i.inhrelid = '16575' ORDER BY inhseqno;
**************************
********* QUERY **********
SELECT c.oid::pg_catalog.regclass FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i WHERE c.oid=i.inhrelid AND i.inhparent = '16575' ORDER BY c.oid::pg_catalog.regclass::pg_catalog.text;
**************************
********* QUERY **********
select partkey,partstrategy from pg_partition where parentid = 16575 order by partkey
**************************
     Table "public.test"
 Column |  Type   | Modifiers 
--------+---------+-----------
 id     | integer | 
Indexes:
    "idx_id_test" btree (id) TABLESPACE pg_default
openGauss=# 
\dt 显示当前数据库中所有的表
 
openGauss=# \dt 
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
                        List of relations
 Schema | Name | Type  | Owner |             Storage              
--------+------+-------+-------+----------------------------------
 public | test | table | omm   | {orientation=row,compression=no}
(1 row)
\dt+ 以扩展方式显示当前数据库所有表信息，比起\dt 多了最后一列描述信息
 
openGauss=# \dt+
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  pg_catalog.pg_size_pretty(pg_catalog.pg_table_size(c.oid)) as "Size",
  c.reloptions as "Storage",
  pg_catalog.obj_description(c.oid, 'pg_class') as "Description"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
                                    List of relations
 Schema | Name | Type  | Owner |  Size   |             Storage              | Description 
--------+------+-------+-------+---------+----------------------------------+-------------
 public | test | table | omm   | 0 bytes | {orientation=row,compression=no} | 
(1 row)
\di 查看当前数据库中索引信息
 
openGauss=# \di
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
 c2.relname as "Table",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
     LEFT JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid
     LEFT JOIN pg_catalog.pg_class c2 ON i.indrelid = c2.oid
WHERE c.relkind IN ('i','I','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
                   List of relations
 Schema |    Name     | Type  | Owner | Table | Storage 
--------+-------------+-------+-------+-------+---------
 public | idx_id_test | index | omm   | test  | 
(1 row)
\di indexname 查看当前数据库某个索引的信息
 
openGauss=# \di idx_id_test
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
 c2.relname as "Table",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
     LEFT JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid
     LEFT JOIN pg_catalog.pg_class c2 ON i.indrelid = c2.oid
WHERE c.relkind IN ('i','I','s','')
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND c.relname ~ '^(idx_id_test)$'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
                   List of relations
 Schema |    Name     | Type  | Owner | Table | Storage 
--------+-------------+-------+-------+-------+---------
 public | idx_id_test | index | omm   | test  | 
(1 row)
\dv 查看当前数据库视图信息
 
openGauss=# \dv
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('v','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
            List of relations
 Schema |  Name  | Type | Owner | Storage 
--------+--------+------+-------+---------
 public | v_test | view | omm   | 
(1 row)
\ds 查看当前数据库序列信息
 
openGauss=# \ds
********* QUERY **********
SELECT n.nspname as "Schema",
  c.relname as "Name",
  CASE c.relkind WHEN 'r' THEN 'table' WHEN 'v' THEN 'view' WHEN 'i' THEN 'index' WHEN 'I' THEN 'global partition index' WHEN 'S' THEN 'sequence' WHEN 's' THEN 'special' WHEN 'f' THEN 'foreign table' WHEN 'm' THEN 'materialized view'  WHEN 'e' THEN 'stream' WHEN 'o' THEN 'contview' END as "Type",
  pg_catalog.pg_get_userbyid(c.relowner) as "Owner",
  c.reloptions as "Storage"
FROM pg_catalog.pg_class c
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('S','')
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
      AND n.nspname !~ '^pg_toast'
      AND c.relname not like 'matviewmap_%'
      AND c.relname not like 'mlog_%'
  AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 1,2;
**************************
             List of relations
 Schema | Name |   Type   | Owner | Storage 
--------+------+----------+-------+---------
 public | sq1  | sequence | omm   | 
(1 row) 
\df 查看当前数据库函数信息
 
openGauss=# \df
********* QUERY **********
SELECT n.nspname as "Schema",
  p.proname as "Name",
  pg_catalog.pg_get_function_result(p.oid) as "Result data type",
  pg_catalog.pg_get_function_arguments(p.oid) as "Argument data types",
  WHEN p.proisagg THEN 'agg'
  WHEN p.proiswindow THEN 'window'
  WHEN p.prorettype = 'pg_catalog.trigger'::pg_catalog.regtype THEN 'trigger'
  ELSE 'normal'
END as "Type" ,
 fencedmode as "fencedmode"
 propackage as "propackage"
 prokind as "prokind"
FROM pg_catalog.pg_proc p
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
WHERE pg_catalog.pg_function_is_visible(p.oid)
      AND n.nspname <> 'pg_catalog'
      AND n.nspname <> 'db4ai'
      AND n.nspname <> 'information_schema'
ORDER BY 1, 2, 4;
**************************
                                                           List of functions
 Schema |   Name    | Result data type |               Argument data types                |  Type  | fencedmode | propackage | prokind 
--------+-----------+------------------+--------------------------------------------------+--------+------------+------------+---------
 public | fuc_worth | numeric          | price numeric, amount integer, OUT worth numeric | normal | f          | f          | f
(1 row)
\dx 查看已安装的扩展程序信息
 
openGauss=# \dx
********* QUERY **********
SELECT e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description"
FROM pg_catalog.pg_extension e LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'::pg_catalog.regclass
ORDER BY 1;
**************************
                               List of installed extensions
      Name       | Version |   Schema   |                   Description                    
-----------------+---------+------------+--------------------------------------------------
 dist_fdw        | 1.0     | pg_catalog | foreign-data wrapper for distfs access
 file_fdw        | 1.0     | pg_catalog | foreign-data wrapper for flat file access
 hdfs_fdw        | 1.0     | pg_catalog | foreign-data wrapper for flat file access
 hstore          | 1.1     | pg_catalog | data type for storing sets of (key, value) pairs
 log_fdw         | 1.0     | pg_catalog | Foreign Data Wrapper for accessing logging data
 mot_fdw         | 1.0     | pg_catalog | foreign-data wrapper for MOT access
 plpgsql         | 1.0     | pg_catalog | PL/pgSQL procedural language
 security_plugin | 1.0     | pg_catalog | provides security functionality
(8 rows)
\x 语法 \x[on|off|auto] 设置语句的输出模式，模式为行的方式输出，执行 \x on 切换为以列的方式来显示
 
openGauss=# \x 
Expanded display is on.
openGauss=# \dx
********* QUERY **********
SELECT e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description"
FROM pg_catalog.pg_extension e LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'::pg_catalog.regclass
ORDER BY 1;
**************************
List of installed extensions
-[ RECORD 1 ]-------------------------------------------------
Name        | dist_fdw
Version     | 1.0
Schema      | pg_catalog
Description | foreign-data wrapper for distfs access
-[ RECORD 2 ]-------------------------------------------------
Name        | file_fdw
Version     | 1.0
Schema      | pg_catalog
Description | foreign-data wrapper for flat file access
-[ RECORD 3 ]-------------------------------------------------
\timing 语法 \timing [on|off] 控制显示SQL的执行时间，默认为off, on 为显示SQL语句的执行时间
 
openGauss=# select * from test;
(1 row)
openGauss=# \timing on
Timing is on.
openGauss=# select * from test;
(1 row)
Time: 0.352 ms
\h 用于获取SQL语句的帮助，例如 \h merge
 
openGauss=# \h merge
Command:     MERGE
Description: insert, update, or delete rows of a table based upon source data
Syntax:
MERGE [/*+ plan_hint */] INTO table_name [ [ AS ] alias ]
USING { { table_name | view_name } | subquery } [ [ AS ] alias ]
ON ( condition )
  WHEN MATCHED THEN
  UPDATE SET { column_name = { expression | DEFAULT } |
          ( column_name [, ...] ) = ( { expression | DEFAULT } [, ...] ) } [, ...]
  [ WHERE condition ]
  WHEN NOT MATCHED THEN 
  INSERT { DEFAULT VALUES |
  [ ( column_name [, ...] ) ] VALUES ( { expression | DEFAULT } [, ...] ) [, ...] [ WHERE condition ] }
? 获取gsql的元命令的帮助
 
openGauss=# \?
General
  \copyright             show openGauss usage and distribution terms
  \g [FILE] or ;         execute query (and send results to file or |pipe)
  \h(\help) [NAME]              help on syntax of SQL commands, * for all commands
  \parallel [on [num]|off] toggle status of execute (currently off)
  \q                     quit gsql
Query Buffer
  \e [FILE] [LINE]       edit the query buffer (or file) with external editor
  \ef [FUNCNAME [LINE]]  edit function definition with external editor
  \p                     show the contents of the query buffer
  \r                     reset (clear) the query buffer
  \w FILE                write query buffer to file
Input/Output
  \copy ...              perform SQL COPY with data stream to the client host
  \echo [STRING]         write string to standard output
  \i FILE                execute commands from file
  \i+ FILE KEY           execute commands from encrypted file
  \ir FILE               as \i, but relative to location of current script
  \ir+ FILE KEY          as \i+, but relative to location of current script
  \o [FILE]              send all query results to file or |pipe
  \qecho [STRING]        write string to query output stream (see \o)
! os_command 用于执行操作系统命令，同oracle的 ！，mysql的 system
 
openGauss-# \! pwd
/home/omm
openGauss-# \! ls
1.sh  create_db_tables.sql  test.sql
\o filename 用于重定向输出到文件，注意这个不是简单的将屏幕的内容输出到文本，而是将SQL语句正确执行的结果输出到文本
 
openGauss-# \o test.out
openGauss-# select * from test;
WARNING:  Session unused timeout.
FATAL:  terminating connection due to administrator command
could not send data to server: Broken pipe
The connection to the server was lost. Attempting reset: Succeeded.
openGauss=# select * from test;
openGauss=# \! cat test.out
(1 row)
openGauss=# select * from pg_tables;
openGauss=#  \! cat test.out
(1 row)
     schemaname     |           tablename           | tableowner | tablespace | hasindexes | hasrules | hastriggers | tablecreator |            created            |         last_ddl_time         
--------------------+-------------------------------+------------+------------+------------+----------+-------------+--------------+-------------------------------+-------------------------------
 pg_catalog         | pg_statistic                  | omm        |            | t          | f        | f           |              |                               | 
\i file.sql
\conninfo 显示gsql中显示会话的连接信息
 
\c[onnect] [DBNAME] 切换数据库
 
openGauss=# \conninfo
You are connected to database "postgres" as user "omm" via socket in "/opt/huawei/tmp" at port "15400".
openGauss=# \c mydb
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "mydb" as user "omm".
mydb=# \conninfo
You are connected to database "mydb" as user "omm" via socket in "/opt/huawei/tmp" at port "15400".
\echo [string] 打印字符串
 
mydb=# \echo Hello World!
Hello World!
\q 退出gsql 
                    连接数据库 使用 -E参数可以显示元命令具体执行的SQL信息[omm@og1 ~]$ gsql -d postgres -p15400 -Egsql ((openGauss 2.1.0 build 590b0f8e) compiled at 2021-09-30 14:29:04 commit 0 last mr  )Non-SSL connection (SSL connection is recommended when requiring high-security)Type "help"
gsql是openGauss提供的在命令行下运行的数据库连接工具。此工具除了具备操作数据库的基本功能，还提供了若干高级特性，便于用户使用。本节只介绍如何使用gsql连接数据库，关于gsql使用方法的更多信息请参考《工具参考》中“客户端工具 > gsql”章节。
缺省情况下，客户端连接数据库后处于空闲状态时会根据参数session_timeout的默认值自动断开连接。如果要关闭超时设置，设置参数s
				GBase 8s是一款高性能、高可用、高可靠的数据库系统。相比GBase 8a，GBase 8s更适合企业级场景，可以应用于核心业务系统和大数据应用场景。针对Windows平台，以下是GBase 8s的安装使用方法。
首先，需要在官网下载GBase 8s for Windows安装包，并将其解压。接着，双击解压后的安装包文件，进入安装界面。这个界面非常简洁明了，只需要按照提示进行下一步操作即可。安装过程中需要进行数据库实例命名、端口号设置、数据库管理员密码设置等操作。
安装完成后，需要进行一些配置和管理操作。GBase 8s采用的是客户端和服务端架构，因此需要创建数据库实例、创建数据库账户、创建以及管理数据库表等操作。在Windows平台下，可以使用GSQL命令行工具或者GBase 8s Studio进行管理操作。
GSQL是GBase 8s的命令行工具，可以进行数据库连接、SQL语句执行以及数据导入等操作。GSQL的使用方法非常类似于MySQL的命令行工具。在安装目录下找到gsql.exe文件，并打开命令行窗口，输入用户名和密码，即可进行数据库管理操作。
GBase 8s Studio是一款GUI工具，可以进行数据库可视化管理操作。在Windows平台下，直接双击打开即可使用。GBase 8s Studio提供了丰富的功能，可以进行数据库实例管理、用户管理、表管理等操作。通过GBase 8s Studio，可以方便地进行数据库备份、恢复、自动化调度等操作。
总之，GBase 8s在Windows平台下的安装使用方法简单明了，用户可以根据自己的业务需求进行数据库管理操作。GBase 8s具有高效、高性能、高可靠等优秀特性，是企业级场景下的一个重要数据库管理工具。
                    Antoniayyy: 
                    连接失败！
原因Connection to 192.168.47.1:26000 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.提示(请尝试以下其一)：
1.验证指定的连接属性.
2.检查Data Studio和服务器版本是否兼容.
3. 检查配置是否正确设置，请在客户端和服务器手册获取更多信息.
datastudio连接数据库显示上面这些怎么办呀
                使用JDBC进行openGauss的读写分离及负载均衡
                    0_0小绵羊0_0: 
                    还是希望写的再通俗一点
                openGauss鲲鹏多核优化解读
                    飘雪冰峰: 
                    请问如何使用 ARMv8.1的原子指令呢，需要使用新版本的GCC编译器去编译源代码么？还是需要修改自己的c语言代码？
                openGauss如何跑各种check
                    weixin_44795979: 
                    请问testname.sql和testname.out文件在哪里下载？
连接数据库 使用 -E参数可以显示元命令具体执行的SQL信息

\q 退出gsql

连接数据库使用 -E参数可以显示元命令具体执行的SQL信息
