also dosent workformeinPostgres9.1. i use the twofunctiondescribedbybartolo-otritwithsomemodification. I modified thefirstfunctiontomake it workforme because the namespaceorthe schema must be presenttoidentify
在PostgreSQL中,ALTER TABLE命令用于修改现有表的结构。当对表进行大规模修改时,可能会导致ALTER TABLE执行变慢的情况。 Alter Table太慢可能由以下几个因素引起:...
ALTER TABLE IF EXISTS tab_name ... ; At this point, you are probably wondering: “But then, is this feature totally useless for me? Is there still no way to alter a table only if it exists?”. Hey, don’t be dramatic! The solution is easy, and it’s probably better than Postgr...
可以看到该语句执行的非常快,在看下alter table获取的锁: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 =# BEGIN; BEGIN =# ALTER TABLE test ADD COLUMN whatever2 int4; ALTER TABLE =# SELECT * FROM pg_locks WHERE pid = pg_backend_pid(); locktype | DATABASE | relation | page | tupl...
[ IF EXISTS ] table_name ADD ( { column_name data_type [ compress_mode ] [ COLLATE collation ] [ column_constraint [ ... ] ] } [, ... ] ); ALTER TABLE [ OFFLINE | [ ONLINE [ WITH ( { online_parameter = value } [, ... ] ) ] ] ] [ IF EXISTS ] table_name MODIFY ...
postgres=# ALTER TABLE score ALTER COLUMN sum_score DROP DEFAULT; ERROR: column "sum_score" of relation "score" is a generated column 12 版本不支持删除字段的Generated Columns属性。 PostgreSQL 13测试 创建测试表,字段sum_score为generated column,如下: postgres=# CREATE TABLE score(stuid int4, chin...
一、概述 AlterRole 在 He3DB 中用来修改已有角色的命令,可以更改角色的权限、密码、有效期限等。 二、AlterRole 命令的执行流程 PostgresMain exec_simple_query →执行简单的 SQL 查询; StartTransactionCommand → 开始
(SQL on OBS or Hadoop) CREATE FOREIGN TABLE (for OBS Import and Export) CREATE FOREIGN TABLE (SQL on other GaussDB(DWS)) CREATE FUNCTION CREATE GROUP CREATE INDEX CREATE REDACTION POLICY CREATE ROW LEVEL SECURITY POLICY CREATE PROCEDURE CREATE RESOURCE POOL CREATE ROLE CREATE SCHEMA CREATE ...
postgres=# CREATE TABLE tab (id integer); CREATE TABLE postgres=# INSERT INTO tab VALUES (5); INSERT 0 1 postgres=# CREATE PUBLICATION mypub FOR TABLE tab; CREATE PUBLICATION 最初に、初期テーブル同期を行うために1レコードを挿入しています。
Third, execute the following statement to change the owner of the testhrdbdatabase from postgresto hr, with the assumption that the hr role already exists. ALTER DATABASE testhrdb OWNER TO hr; If the hr role does not exist, you can create it by using the CREATE ROLE statement: CREATE RO...