原始信息在pg_index中。

只需要执行:\d table_name

但是我不确定你说没有列的信息是什么意思。

例如:

# \d pg_class
       Table "pg_catalog.pg_class"
     Column      |   Type    | Modifiers
-----------------+-----------+-----------
 relname         | name      | not null
 relnamespace    | oid       | not null
 reltype         | oid       | not null
 reloftype       | oid       | not null
 relowner        | oid       | not null
 relam           | oid       | not null
 relfilenode     | oid       | not null
 reltablespace   | oid       | not null
 relpages        | integer   | not null
 reltuples       | real      | not null
 reltoastrelid   | oid       | not null
 reltoastidxid   | oid       | not null
 relhasindex     | boolean   | not null
 relisshared     | boolean   | not null
 relistemp       | boolean   | not null
 relkind         | "char"    | not null
 relnatts        | smallint  | not null
 relchecks       | smallint  | not null
 relhasoids      | boolean   | not null
 relhaspkey      | boolean   | not null
 relhasexclusion | boolean   | not null
 relhasrules     | boolean   | not null
 relhastriggers  | boolean   | not null
 relhassubclass  | boolean   | not null
 relfrozenxid    | xid       | not null
 relacl          | aclitem[] |
 reloptions      | text[]    |
Indexes:
    "pg_class_oid_index" UNIQUE, btree (oid)
    "pg_class_relname_nsp_index" UNIQUE, btree (relname, relnamespace)

它清楚地显示给定索引在该表上的列。

\d tablename显示了8.3.8版本中的列名。

 "username_idx" UNIQUE, btree (username), tablespace "alldata1"

\d table_name显示了来自psql的这些信息，但是如果你想使用SQL从数据库中获取这些信息，那么可以看看从PostgreSQL中提取META信息。

我在我的实用程序中使用这些信息来报告来自db schema的一些信息，以比较测试和生产环境中的PostgreSQL数据库。

一些样本数据…

create table test (a int, b int, c int, constraint pk_test primary key(a, b));
create table test2 (a int, b int, c int, constraint uk_test2 unique (b, c));
create table test3 (a int, b int, c int, constraint uk_test3b unique (b), constraint uk_test3c unique (c), constraint uk_test3ab unique (a, b));

使用pg_get_indexdef函数:

select pg_get_indexdef(indexrelid) from pg_index where indrelid = 'test'::regclass;

                    pg_get_indexdef
--------------------------------------------------------
 CREATE UNIQUE INDEX pk_test ON test USING btree (a, b)
(1 row)


select pg_get_indexdef(indexrelid) from pg_index where indrelid = 'test2'::regclass;
                     pg_get_indexdef
----------------------------------------------------------
 CREATE UNIQUE INDEX uk_test2 ON test2 USING btree (b, c)
(1 row)


select pg_get_indexdef(indexrelid) from pg_index where indrelid ='test3'::regclass;
                      pg_get_indexdef
------------------------------------------------------------
 CREATE UNIQUE INDEX uk_test3b ON test3 USING btree (b)
 CREATE UNIQUE INDEX uk_test3c ON test3 USING btree (c)
 CREATE UNIQUE INDEX uk_test3ab ON test3 USING btree (a, b)
(3 rows)

创建一些测试数据…

create table test (a int, b int, c int, constraint pk_test primary key(a, b));
create table test2 (a int, b int, c int, constraint uk_test2 unique (b, c));
create table test3 (a int, b int, c int, constraint uk_test3b unique (b), constraint uk_test3c unique (c),constraint uk_test3ab unique (a, b));

列出索引的索引和列:

select
    t.relname as table_name,
    i.relname as index_name,
    a.attname as column_name
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
order by
    t.relname,
    i.relname;

 table_name | index_name | column_name
------------+------------+-------------
 test       | pk_test    | a
 test       | pk_test    | b
 test2      | uk_test2   | b
 test2      | uk_test2   | c
 test3      | uk_test3ab | a
 test3      | uk_test3ab | b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

卷起列名:

select
    t.relname as table_name,
    i.relname as index_name,
    array_to_string(array_agg(a.attname), ', ') as column_names
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname like 'test%'
group by
    t.relname,
    i.relname
order by
    t.relname,
    i.relname;

 table_name | index_name | column_names
------------+------------+--------------
 test       | pk_test    | a, b
 test2      | uk_test2   | b, c
 test3      | uk_test3ab | a, b
 test3      | uk_test3b  | b
 test3      | uk_test3c  | c

结合其他代码并创建一个视图:

CREATE OR REPLACE VIEW view_index AS 
SELECT
     n.nspname  as "schema"
    ,t.relname  as "table"
    ,c.relname  as "index"
    ,pg_get_indexdef(indexrelid) as "def"
FROM pg_catalog.pg_class c
    JOIN pg_catalog.pg_namespace n ON n.oid        = c.relnamespace
    JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid
    JOIN pg_catalog.pg_class t ON i.indrelid   = t.oid
WHERE c.relkind = 'i'
    and n.nspname not in ('pg_catalog', 'pg_toast')
    and pg_catalog.pg_table_is_visible(c.oid)
ORDER BY
     n.nspname
    ,t.relname
    ,c.relname;

如果你想保持索引中的列顺序，这里有一个(非常丑陋的)方法:

select table_name,
    index_name,
    array_agg(column_name)
from (
    select
        t.relname as table_name,
        i.relname as index_name,
        a.attname as column_name,
        unnest(ix.indkey) as unn,
        a.attnum
    from
        pg_class t,
        pg_class i,
        pg_index ix,
        pg_attribute a
    where
        t.oid = ix.indrelid
        and i.oid = ix.indexrelid
        and a.attrelid = t.oid
        and a.attnum = ANY(ix.indkey)
        and t.relkind = 'r'
        and t.relnamespace = <oid of the schema you're interested in>
    order by
        t.relname,
        i.relname,
        generate_subscripts(ix.indkey,1)) sb
where unn = attnum
group by table_name, index_name

列顺序存储在pg_index中。indkey列，我是根据这个数组的下标排序的。

查询结果:

table |     column     |          type          | notnull |  index_name  | is_index | primarykey | uniquekey | default
-------+----------------+------------------------+---------+--------------+----------+-   -----------+-----------+---------
 nodes | dns_datacenter | character varying(255) | f       |              | f        | f          | f         |
 nodes | dns_name       | character varying(255) | f       | dns_name_idx | t        | f          | f         |
 nodes | id             | uuid                   | t       | nodes_pkey   | t        | t          | t         |
(3 rows)

查询:

SELECT  
c.relname AS table,
f.attname AS column,  
pg_catalog.format_type(f.atttypid,f.atttypmod) AS type,
f.attnotnull AS notnull,  
i.relname as index_name,
CASE  
    WHEN i.oid<>0 THEN 't'  
    ELSE 'f'  
END AS is_index,  
CASE  
    WHEN p.contype = 'p' THEN 't'  
    ELSE 'f'  
END AS primarykey,  
CASE  
    WHEN p.contype = 'u' THEN 't' 
    WHEN p.contype = 'p' THEN 't' 
    ELSE 'f'
END AS uniquekey,
CASE
    WHEN f.atthasdef = 't' THEN d.adsrc
END AS default  FROM pg_attribute f  
JOIN pg_class c ON c.oid = f.attrelid  
JOIN pg_type t ON t.oid = f.atttypid  
LEFT JOIN pg_attrdef d ON d.adrelid = c.oid AND d.adnum = f.attnum  
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace  
LEFT JOIN pg_constraint p ON p.conrelid = c.oid AND f.attnum = ANY (p.conkey)  
LEFT JOIN pg_class AS g ON p.confrelid = g.oid
LEFT JOIN pg_index AS ix ON f.attnum = ANY(ix.indkey) and c.oid = f.attrelid and c.oid = ix.indrelid 
LEFT JOIN pg_class AS i ON ix.indexrelid = i.oid 

WHERE c.relkind = 'r'::char  
AND n.nspname = 'public'  -- Replace with Schema name 
--AND c.relname = 'nodes'  -- Replace with table name, or Comment this for get all tables
AND f.attnum > 0
ORDER BY c.relname,f.attname;

有一个简单的解决方案:

SELECT 
  t.relname table_name,
  ix.relname index_name,
  indisunique,
  indisprimary, 
  regexp_replace(pg_get_indexdef(indexrelid), '.*\((.*)\)', '\1') columns
FROM pg_index i
JOIN pg_class t ON t.oid = i.indrelid
JOIN pg_class ix ON ix.oid = i.indexrelid
WHERE t.relname LIKE 'test%'

`

该命令还显示了表变量、索引和约束的视图

=# \d table_name;

例子:

testannie=# \d dv.l_customer_account;

在处理索引时，索引中构造列的顺序与列本身同样重要。

下面的查询以排序的方式列出给定表的所有索引及其所有列。

SELECT
  table_name,
  index_name,
  string_agg(column_name, ',')
FROM (
       SELECT
         t.relname AS table_name,
         i.relname AS index_name,
         a.attname AS column_name,
         (SELECT i
          FROM (SELECT
                  *,
                  row_number()
                  OVER () i
                FROM unnest(indkey) WITH ORDINALITY AS a(v)) a
          WHERE v = attnum)
       FROM
         pg_class t,
         pg_class i,
         pg_index ix,
         pg_attribute a
       WHERE
         t.oid = ix.indrelid
         AND i.oid = ix.indexrelid
         AND a.attrelid = t.oid
         AND a.attnum = ANY (ix.indkey)
         AND t.relkind = 'r'
         AND t.relname LIKE 'tablename'
       ORDER BY table_name, index_name, i
     ) raw
GROUP BY table_name, index_name

请尝试下面的查询以深入到所需的索引

查询如下-我亲自尝试过，并经常使用它。

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 'S' THEN 'sequence' WHEN 's' THEN 'special' END as "Type",
  u.usename as "Owner",
 c2.relname as "Table"
FROM pg_catalog.pg_class c
     JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid
     JOIN pg_catalog.pg_class c2 ON i.indrelid = c2.oid
     LEFT JOIN pg_catalog.pg_user u ON u.usesysid = c.relowner
     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('i','')
      AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
      AND pg_catalog.pg_table_is_visible(c.oid)
      AND c2.relname like '%agg_transaction%' --table name
      AND nspname = 'edjus' -- schema name 
ORDER BY 1,2;

类似于接受的答案，但有左连接pg_attribute作为正常连接或查询pg_attribute不给出索引，如: 为用户创建唯一索引unique_user_name_index (lower(name))

select 
    row_number() over (order by c.relname),
    c.relname as index, 
    t.relname as table, 
    array_to_string(array_agg(a.attname), ', ') as column_names 
from pg_class c
join pg_index i on c.oid = i.indexrelid and c.relkind='i' and c.relname not like 'pg_%' 
join pg_class t on t.oid = i.indrelid
left join pg_attribute a on a.attrelid = t.oid and a.attnum = ANY(i.indkey) 
group by t.relname, c.relname order by c.relname;

@cope360的精彩回答，转换为使用连接语法。

select t.relname as table_name
     , i.relname as index_name
     , array_to_string(array_agg(a.attname), ', ') as column_names
from pg_class t
join pg_index ix
on t.oid = ix.indrelid
join pg_class i
on i.oid = ix.indexrelid
join pg_attribute a
on a.attrelid = t.oid
and a.attnum = ANY(ix.indkey)
where t.relkind = 'r'
and t.relname like 'test%'
group by t.relname
       , i.relname
order by t.relname
       , i.relname
;

下面是一个包装cope360答案的函数:

CREATE OR REPLACE FUNCTION getIndices(_table_name varchar)
  RETURNS TABLE(table_name varchar, index_name varchar, column_name varchar) AS $$
  BEGIN
    RETURN QUERY
    select
    t.relname::varchar as table_name,
    i.relname::varchar as index_name,
    a.attname::varchar as column_name
from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    and t.relname = _table_name
order by
    t.relname,
    i.relname;
  END;
  $$ LANGUAGE plpgsql;

用法:

select * from getIndices('<my_table>')

我认为这个版本在这个线程上还不存在:它提供了列名列表和索引的ddl。

CREATE OR REPLACE VIEW V_TABLE_INDEXES AS

SELECT
     n.nspname  as "schema"
    ,t.relname  as "table"
    ,c.relname  as "index"
    ,i.indisunique AS "is_unique"
    ,array_to_string(array_agg(a.attname), ', ') as "columns"
    ,pg_get_indexdef(i.indexrelid) as "ddl"
FROM pg_catalog.pg_class c
    JOIN pg_catalog.pg_namespace n ON n.oid        = c.relnamespace
    JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid
    JOIN pg_catalog.pg_class t ON i.indrelid   = t.oid
    JOIN pg_attribute a ON a.attrelid = t.oid AND a.attnum = ANY(i.indkey)
WHERE c.relkind = 'i'
      and n.nspname not in ('pg_catalog', 'pg_toast')
      and pg_catalog.pg_table_is_visible(c.oid)
GROUP BY
    n.nspname
    ,t.relname
    ,c.relname
    ,i.indisunique
    ,i.indexrelid
ORDER BY
    n.nspname
    ,t.relname
    ,c.relname;

我发现使用函数的索引不链接到列名，所以偶尔你会发现一个索引列表，例如一个列名，而实际上是使用3。

例子:

CREATE INDEX ui1 ON table1 (coalesce(col1,''),coalesce(col2,''),col3)

该查询仅返回'col3'作为索引上的列，但DDL显示了索引中使用的全部列。

PostgreSQL (pg_indexes):

SELECT * FROM pg_indexes WHERE tablename = 'mytable';

MySQL(显示索引)

SHOW INDEX FROM mytable;

# \迪

最简单和最短的方法是\di，它将列出当前数据库中的所有索引。

$ \di
                      List of relations
 Schema |            Name             | Type  |  Owner   |     Table     
--------+-----------------------------+-------+----------+---------------
 public | part_delivery_index         | index | shipper  | part_delivery
 public | part_delivery_pkey          | index | shipper  | part_delivery
 public | shipment_by_mandator        | index | shipper  | shipment_info
 public | shipment_by_number_and_size | index | shipper  | shipment_info
 public | shipment_info_pkey          | index | shipper  | shipment_info
(5 rows)

\di是\d命令的“小兄弟”，该命令将列出当前数据库的所有关系。因此\di当然代表“显示我这个数据库索引”。

输入\diS将列出系统范围内使用的所有索引，这意味着您也将获得所有pg_catalog索引。

$ \diS
                                      List of relations
   Schema   |                   Name                    | Type  |  Owner   |          Table
------------+-------------------------------------------+-------+----------+-------------------------
 pg_catalog | pg_aggregate_fnoid_index                  | index | postgres | pg_aggregate
 pg_catalog | pg_am_name_index                          | index | postgres | pg_am
 pg_catalog | pg_am_oid_index                           | index | postgres | pg_am
 pg_catalog | pg_amop_fam_strat_index                   | index | postgres | pg_amop
 pg_catalog | pg_amop_oid_index                         | index | postgres | pg_amop
 pg_catalog | pg_amop_opr_fam_index                     | index | postgres | pg_amop
 pg_catalog | pg_amproc_fam_proc_index                  | index | postgres | pg_amproc
 pg_catalog | pg_amproc_oid_index                       | index | postgres | pg_amproc
 pg_catalog | pg_attrdef_adrelid_adnum_index            | index | postgres | pg_attrdef
--More-- 

使用这两个命令，您可以在它之后添加一个+，以获得更多信息，如大小-磁盘空间-索引需要和描述(如果可用)。

$ \di+
                                 List of relations
 Schema |            Name             | Type  |  Owner   |     Table     | Size  | Description 
--------+-----------------------------+-------+----------+---------------+-------+-------------
 public | part_delivery_index         | index | shipper  | part_delivery | 16 kB | 
 public | part_delivery_pkey          | index | shipper  | part_delivery | 16 kB | 
 public | shipment_by_mandator        | index | shipper  | shipment_info | 19 MB | 
 public | shipment_by_number_and_size | index | shipper  | shipment_info | 19 MB | 
 public | shipment_info_pkey          | index | shipper  | shipment_info | 53 MB | 
(5 rows)

在psql中，你可以很容易地找到关于输入\?

延伸到@Cope360的好答案。要获取某个表(如果它们是相同的表名但不同的模式)，只需使用表OID。

select
     t.relname as table_name
    ,i.relname as index_name
    ,a.attname as column_name
    ,a.attrelid tableid

from
    pg_class t,
    pg_class i,
    pg_index ix,
    pg_attribute a
where
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and a.attrelid = t.oid
    and a.attnum = ANY(ix.indkey)
    and t.relkind = 'r'
    -- and t.relname like 'tbassettype'
    and a.attrelid = '"dbLegal".tbassettype'::regclass
order by
    t.relname,
    i.relname;

解释:我有表名'tbassettype'在两个模式'dbAsset'和'dbLegal'。要在dbLegal上只获取表，只需让a.attrelid =它的OID。

稍微修改一下@cope360的回答:

create table test (a int, b int, c int, constraint pk_test primary key(c, a, b));
select i.relname as index_name,
       ix.indisunique as is_unique,
       a.attname as column_name,
from pg_class c
       inner join pg_index ix on c.oid=ix.indrelid
       inner join pg_class i on ix.indexrelid=i.oid
       inner join pg_attribute a on a.attrelid=c.oid and a.attnum=any(ix.indkey)
where c.oid='public.test'::regclass::oid
order by array_position(ix.indkey, a.attnum) asc;

这将显示索引列的正确顺序:

index_name      is_unique  column_name
pk_test         true       c
pk_test         true       a
pk_test         true       b

select t.relname as table_name, 
       i.relname as index_name, 
       array_position(ix.indkey,a.attnum) pos, 
       a.attname as column_name
from pg_class t
join pg_index ix on t.oid = ix.indrelid
join pg_class i on i.oid = ix.indexrelid
join pg_attribute a on a.attrelid = t.oid and a.attnum = ANY(ix.indkey)
where t.relkind = 'r'
and t.relname like 'orders'
order by t.relname, i.relname, array_position(ix.indkey,a.attnum)

@cope360接受的答案很好，但我想要一些更像Oracle的DBA_IND_COLUMNS, ALL_IND_COLUMNS和USER_IND_COLUMNS(例如，报告表/索引模式和索引在多列索引中的位置)，所以我把接受的答案改编成这样:

with
 ind_cols as (
select
    n.nspname as schema_name,
    t.relname as table_name,
    i.relname as index_name,
    a.attname as column_name,
    1 + array_position(ix.indkey, a.attnum) as column_position
from
     pg_catalog.pg_class t
join pg_catalog.pg_attribute a on t.oid    =      a.attrelid 
join pg_catalog.pg_index ix    on t.oid    =     ix.indrelid
join pg_catalog.pg_class i     on a.attnum = any(ix.indkey)
                              and i.oid    =     ix.indexrelid
join pg_catalog.pg_namespace n on n.oid    =      t.relnamespace
where t.relkind = 'r'
order by
    t.relname,
    i.relname,
    array_position(ix.indkey, a.attnum)
)
select * 
from ind_cols
where schema_name = 'test'
  and table_name  = 'indextest'
order by schema_name, table_name
;

这将给出如下输出:

 schema_name | table_name | index_name | column_name | column_position 
-------------+------------+------------+-------------+-----------------
 test        | indextest  | testind1   | singleindex |               1
 test        | indextest  | testind2   | firstoftwo  |               1
 test        | indextest  | testind2   | secondoftwo |               2
(3 rows)

也许您希望获得实际的CREATE INDEX语句，以便您可以删除它们并在以后作为管理流程的一部分重新创建(这是我的情况)。在这种情况下，您可以使用pg_dump仅转储post-data部分，然后从其中grep 'CREATE INDEX'。

PGPASSWORD=<pwd> pg_dump --host <host> --port <port> -U <user> -d <database> --section=post-data > post-data.sql
grep 'CREATE INDEX' postdata.sql > create_index.sql

这可能是有帮助的，因为一些索引可能很难重新创建，例如那些使用特定op类的索引(例如gin_trgm_ops)或其他一些 我通常很难重新开始。