a.attname AS name, a.attnotnull AS notnull FROM pg_class AS c,pg_attribute AS a WHERE c.relname = 'tablename' AND a.attrelid = c.oid AND a.attnum>0查询所有表名称以及字段含义1 2 3 select c.relname 表名,cast(obj_description(relfilenode,'pg_class') as varchar) 名称,a.attname...
n.nspnameAS"Schema",CASEd.defaclobjtypeWHEN'r'THEN'table'WHEN'S'THEN'sequence'WHEN'f'THEN'function'WHEN'T'THEN'type'ENDAS"Type", pg_catalog.array_to_string(d.defaclacl, E', ')AS"Access privileges"FROMpg_catalog.pg_default_acl dLEFTJOINpg_catalog.pg_namespace nONn.oid=d.defaclname...
2.7、使用pg_dirtyread查看表,dead为t表示数据已经删除 testdb=# SELECT * FROM pg_dirtyread('t1')AS t(tableoid oid, ctid tid, xmin xid, xmax xid, cmin cid, cmax cid, dead boolean,id int, name text);tableoid | ctid | xmin ...
select*from pg_database; 代码语言:javascript 代码运行次数:0 运行 AI代码解释 postgres=# select*from pg_database;oid|datname|datdba|encoding|datcollate|datctype|datistemplate|datallowconn|datconnlimit|datlastsysoid|datfrozenxid|datminmxid|dattablespace|datacl---+---+---+---+---+---+-...
tablename LIMIT 1) FROM pg_tables pt 3、查询指定表中的所有字段、类型、注释 代码语言:javascript 代码运行次数:0 运行 AI代码解释 select a.attnum,a.attname,concat_ws('',t.typname,SUBSTRING(format_type(a.atttypid,a.atttypmod) from '\(.*\)')) as type,d.description from pg_class c,...
SELECT amname,opfname FROM pg_opfamily,pg_am WHERE opfmethod=pg_am.oid AND amname='btree'; 11.查找从未使用过的索引 如果index_scans为0或接近0,则可以删除这些索引。 SELECT s.relname AS table_name, indexrelname AS index_name, i.indisunique, ...
SETmax_parallel_workers=DEFAULT;SETdefault_table_access_method=DEFAULT; 五、常用函数 create_immv 使用create_immv函数去创建IMMV。 create_immv(immv_nametext,view_definitiontext)RETURNSbigint create_immv定义一个新的IMMV。一个名为immv_name的表被创建,并且被view_definition指定的查询被执行并使用结果填...
-- 查询分区表stu_info_young的分区约束 select pg_get_partition_constraintdef('stu_info_young'::regclass); 3. 定位记录实际所存储的分区表 相关SQL如下所示,定位父表stu_info中id为2的记录实际存储的分区表 -- 通过系统表pg_class确定该 tableoid 所表示的表 select relname as table_name from pg_ca...
PostgreSQL void table_close(Relation relation, LOCKMODE lockmode); openGauss #define heap_close(r,l) relation_close(r,l) void relation_close(Relation relation, LOCKMODE lockmode); 作用 close any relation 差异 名称不同 序号API_02 PostgreSQL Relation table_open(Oid relationId, LOCKMODE lockmode...