SQL> select owner, table_name, constraint_name, constraint_type from user_constraints where table_name='EMP'; 查看创建主键的SQL SELECT DBMS_METADATA.GET_DDL('CONSTRAINT','EMP_PK') FROM DUAL; 查看创建外键的SQL SQL> SELECT DBMS_METADATA.GET_DDL('REF_CONSTRAINT','EMP_FK_DEPT') FROM DUAL; ...
DDL replication is not active on Logical Standby nodes until they are promoted. Note that some BDR management functions act like DDL, meaning that they will attempt to take global locks and their actions will be replicated, if DDL replication is active. The full list of replicated functions is...
We explore the separation of SQL into its four principal sublanguages and explain the meaning behind each of them. When you’re learning SQL – perhaps through LearnSQL.com’s very own comprehensive SQL Basics course – you may have come across the terms DDL, DML, DQL, and DCL. And maybe...
it is considered to be a subset of SQL (Structured Query Language). SQL often uses imperative verbs with normal English such as sentences to implement database modifications. Hence, DDL does not show up as a different language in an SQL database, but does define changes in the data...
Some BDR management functions act like DDL, meaning that they attempt to take global locks, and their actions are replicated if DDL replication is active. The full list of replicated functions is listed in BDR functions that behave like DDL. DDL executed on temporary tables never need global lo...
| [`tidb_enable_fast_create_table`](/system-variables.md#tidb_enable_fast_create_table-new-in-v800) | Modified | Changes the default value from `OFF` to `ON` after further tests, meaning that the [accelerated table creation](/accelerated-table-creation.md) feature is enabled by default....
SQL> create table tb2 (id int primary key references tb1(id)); Table created. SQL> insert into tb1 values(1); 1 row created. SQL> commit; Commit complete. SQL> insert into tb2 values(1); 1 row created. SQL> commit; SQL> select dbms_metadata.get_ddl('TABLE','TB2','TEST') fro...
AUTHIDproperty values are exposed in the static data dictionary view*_PROCEDURES. For units for whichAUTHIDhas meaning, the view shows the valueCURRENT_USERorDEFINER; for other units, the view showsNULL. For stored PL/SQL units that you create or alter with the following statements, you can ...
The minvalue, maxvalue, start, inc, and cache columns have the same meaning as in the pg_sequences view, and show the options with which the sequence was created. The lastval column shows the latest allocated or reserved value in a distributed sequence object. This doesn't mean that t...
Todeploy(meaning activate) DDL replication for a given replication set, run: --Deploy any set_configs with given set_name:SELECTpgl_ddl_deploy.deploy(set_name);--Deploy only a single set_config_id:SELECTpgl_ddl_deploy.deploy(set_config_id); ...