To define a foreign key, you can use a foreign key constraint. PostgreSQL foreign key constraint syntax The following illustrates a foreign key constraint syntax: [CONSTRAINT fk_name] FOREIGN KEY(fk_columns) REFERENCES parent_table(parent_key_columns) [ON DELETE delete_action] [ON UPDATE update...
(this is also a warning class per the SQL standard) */ #define ERRCODE_NO_DATA MAKE_SQLSTATE('0','2','0','0','0') #define ERRCODE_NO_ADDITIONAL_DYNAMIC_RESULT_SETS_RETURNED MAKE_SQLSTATE('0','2','0','0','1') /* Class 03 - SQL Statement Not Yet Complete */ #define ...
Command:CREATETRIGGERDescription:define anewtriggerSyntax:CREATE[CONSTRAINT]TRIGGERname{BEFORE|AFTER|INSTEADOF}{event[OR...]}ONtable_name[FROMreferenced_table_name]{NOTDEFERRABLE|[DEFERRABLE]{INITIALLYIMMEDIATE|INITIALLYDEFERRED}}[FOR[EACH]{ROW|STATEMENT}][WHEN(condition)]EXECUTEPROCEDUREfunction_name(argume...
-D, --define=VARNAME=VALUE定义变量以供自定义脚本使用 -j, --jobs=NUM指定线程数 -l, --log将事务时间写入日志文件 -L, --latency-limit=NUM将持续时间超过M毫秒的事务计数为延迟 -M, --protocol=simple|extended|prepared查询的协议(默认:simple) ...
Foreign key –show you how to define foreign key constraints when creating a new table or adding foreign key constraints for existing tables. DELETE CASCADE –show you how to automatically delete rows in child tables when the corresponding rows in the parent table are deleted. CHECK constraint –...
3)Maintenance_work_mem:用于限制vacuum、create index、reindex、alter table add foreign key所使用的最大内存量。 由于每个session只能执行这些操作中的一个,而且PG也会限制这些操作同时执行,所以Maintenance_work_mem可以比work_mem设置的更大一些。 注:当autovacuum运行时,可能会分配多达autovacuum_max_workers次的内...
ALTER TABLE rental ADD CONSTRAINT fk_customer_id FOREIGN KEY (customer_id) REFERENCES customers(customer_id); 6. Exclusion Constraints:Exclusion constraints ensure that no two rows in a table satisfy a specified predicate. This allows you to define custom constraints beyond simple unique or check ...
Partitioned tables do not support UNIQUE, PRIMARY KEY, EXCLUDE,orFOREIGN KEY constraints; however, you can define these constraints on individual partitions. When using range partitioning, a NOT NULL constraint isaddedto each non-expression column in the partition key. ...
#define ShareLock 5 /* CREATE INDEX (WITHOUT CONCURRENTLY) */ #define ShareRowExclusiveLock 6 /* CREATE TRIGGER and many forms of ALTER TABLE, like EXCLUSIVE MODE, but allows ROW SHARE */ #define ExclusiveLock 7 /* REFRESH MATERIALIZED VIEW CONCURRENTLY, blocks ROW SHARE/SELECT...FOR UPDATE...
postgres=#\helpcreatetablespace;Command:CREATETABLESPACEDescription:defineanewtablespaceSyntax:CREATETABLESPACEtablespace_name[OWNER{new_owner|CURRENT_ROLE|CURRENT_USER|SESSION_USER}]LOCATION'directory'[WITH(tablespace_option=value[,...])]--创建表空间abc_tbs,实现准备对应的目录[postgres@centos79~]$ls-lrt...