akendb=# select n_live_tup as estimate_rows from pg_stat_all_tables where relname = 'aken01'; estimate_rows --- 50002378 (1 row) Time: 13.768 ms akendb=# 2)方法二: akendb=# select reltuples::bigint as estimate_rows from pg_class where relname = 'aken01'; estimate_rows --- ...
FOR ALL TABLES:将当前库中所有表添加到发布中,包括以后在这个库中新建的表。这种模式相当于在全库级别逻辑复制所有表。当然一个 PostgreSQL 实例上可以运行多个数据库,这仍然是仅复制了 PostgreSQL 实例上的一部分数据。 如果想查询刚创建的发布信息,在发布节点上查询问 pg_publication 视图即可,如下所示 postgres=...
定义默认的访问权限。 ALTERDEFAULTPRIVILEGES[FOR{ROLE|USER}target_role[,...]][INSCHEMAschema_name[,...]]abbreviated_grant_or_revoke where abbreviated_grant_or_revoke is oneof:GRANT{{SELECT|INSERT|UPDATE|DELETE|TRUNCATE|REFERENCES|TRIGGER}[,...]|ALL[PRIVILEGES]}ONTABLESTO{[GROUP]role_name|PUBL...
（1）查看数据库的oid。postgres=# select oid,datname from pg_database; # 输出的信息如下： ...
or DELETE operations.INSTEAD OF triggers are fired once for each row that needs to be modified in the view.It is the responsibility of the trigger's function to perform the necessary modifications to the underlying base tables and, where appropriate, return the modified row as it will appear...
-- change distribution columnSELECTalter_distributed_table('github_events', distribution_column:='event_id');-- change shard count of all tables in colocation groupSELECTalter_distributed_table('github_events', shard_count:=6, cascade_to_colocated:=true);-- change colocationSELECTalter_distributed...
colocationid int Unique identifier for the colocation group this row corresponds to. shardcount int Shard count for all tables in this colocation group replicationfactor int Replication factor for all tables in this colocation group. distributioncolumntype oid The type of the distribution column for ...
(select row_number()over(order by id)rownumber,* from pagetest)a where rownumber between 9901 and 9950 --写法5,在csdn上一帖子看到的,row_number() 变体,不基于已有字段产生记录序号,先按条件筛选以及排好序,再在结果集上给一常量列用于产生记录序号 ...
[ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] ...
statistics for the data you’d see with SELECT column FROM table, whereas the stainherit = false row represents the results of SELECT column FROM ONLY table. 其实就是如果pg_statistic系统表中列条目的stainherit字段为true,该行代表所有继承子表列的统计信息;如果为false,该行代表starelid指定表staattnu...