通用描述ALTER TABLESPACE SET语句用于更改分布式部署中一个已存在的表空间集的相关属性。...#语句定义alter tablespace set::=语法图代码syntax::= ALTER TABLESPACE SET tablespace_set_name (MAXSIZE size_clause...示例(分布式部署)ALTER TABLESPACE SET tbs_tb ADD DATABUCKET '?/lscfile3' MAXSIZE 1G;Copied!...示例(分布式部署)ALTER TABLESPACE SET tbs_tb ALTER DATABUCKET '?/lscfile3' READONLY;Copied!...#bucket_name同alter_databucket_clause语句描述。示例(分布式部署)ALTER TABLESPACE SET tbs_tb DROP DATABUCKET '?
_name_ SET SCHEMA _new_schema_ ALTER CONVERSION 修改一个编码转换的定义。...ALTER DOMAIN name { SET DEFAULT expression | DROP DEFAULT } ALTER DOMAIN name { SET | DROP } NOT NULL...ALTER INDEX name OWNER TO new_owner ALTER INDEX name SET TABLESPACE indexspace_name ALTER INDEX name...DEFAULT ALTER [ COLUMN ] column { SET | DROP } NOT NULL ALTER [ COLUMN ] column SET STATISTICS integer...ALTER USER name [ [ WITH ] option [ ... ] ] ALTER USER name RENAME TO new_name ALTER USER name SET parameter
postgres=# alter system set work_mem = '5MB'; ERROR: ALTER SYSTEM is not allowed in this environment...Mode: logical Hits: 1000 Misses: 50 -> Index Scan using small_table_pkey on small_table 4 db_user_namespace...,A 和 B 库分别属于两个你的客户,这两个客户都要在自己建的库创建一个管理员账号,这个账号叫 admin,在他们创建这个用户后,失败了,因为在PG智能有一个用户叫admin,实际上不是的,PG支持 db_user_namespace...15 default_transaction_deferrable SET default_transaction_isolation = 'serializable'; SET default_transaction_deferrable...SERIALIZABLE隔离级别的事务时减少事务和事务之间产生冲突的可能,具体原理就是延迟SERIALIZABLE事务与其他事务运行的时间差,延迟SERIALIZABLE事务的执行。
ALTER SESSION#通用描述ALTER SESSION用于动态地改变所在会话的属性或会话级的系统配置,此类改变仅在当前会话生效,会话断开后将恢复为初始值。...#语句定义alter session::=语法图代码syntax::= ALTER SESSION set_clauseset_clause::=语法图代码syntax::= SET parameter_name...------------------ ------- DATE_FORMAT yyyy-mm-dd hh24:mi:ss -- 会话级参数ISOLATION_LEVEL-- 设置会话的默认隔离级别为SERIALIZABLE...ALTER SESSION SET ISOLATION_LEVEL = SERIALIZABLE;-- 设置会话的默认隔离级别为READ COMMITTED。...ALTER SESSION SET ISOLATION_LEVEL = READ COMMITTED;
car_fk(id); 实体对象:在内存中有id属性的 值对象:没有id的,依赖其他对象存在 一对多关系 一的一方保存多一方的一个集合,最好使用set...String owner; private String phone; private String address; private Set items = new...HashSet(); } public class Item implements Serializable{ private int id; private String...{ private int id; private String name; private int period; private Set...private int id; private String name; private Date birthday; private Set courses
可参考数据强一致性(XA事务)章节章节描述 READ UNCOMMITTED 不支持 SERIALIZABLE 支持 XA模式可完整支持, 普通模式下会存在读到部分提交的情况 SET GLOBAL...TRANSACTION REPEATABLE READ 不支持 不支持SET GLOBAL的方式,只支持SET SESSION READ COMMITTED 不支持 不支持SET GLOBAL的方式...,只支持SET SESSION READ UNCOMMITTED 不支持 SERIALIZABLE 不支持 SET SESSION TRANSACTION READ ONLY 支持...*:表示某个数据库中的所有表/视图,db_name 指定数据库名; db_name.tbl_name:表示某个数据库中的某个表/视图,db_name 数据库名,tbl_name 表名; tbl_name...|db_name.
♣ 题目部分 在Oracle中,举例说明“集合操作关联转变(Set Join Conversion)”查询转换。...--------------------------------------------------------- 61 recursive calls 5 db...sorts (memory) 0 sorts (disk) 8 rows processed LHR@orclasm > LHR@orclasm > ALTER...SESSION SET "_CONVERT_SET_TO_JOIN"=TRUE; Session altered....--------------------------------------------------------- 61 recursive calls 5 db
Oracle 数据库的事物隔离级别设置 设置一个事物的隔离级别: SET TRANSACTION ISOLATION LEVEL [READ COMMITED | SERIALIZABLE |...READ ONLY]; 设置一个会话的隔离级别: ALTER SESSION SET ISOLATION_LEVEL [READ COMMITTED| SERIALIZABLE]; 2....-- 获取全局隔离级别 SELECT @@global.tx_isolation; --获取会话隔离级别 SELECT @@tx_isolation; 设置隔离级别: --全局隔离级别设置 SET...]; --会话隔离级别设置 SET SESSION TRANSACTION ISOLATION LEVEL [ READ UNCOMMITTED | READ COMMITTED...| REPEATABLE READ | SERIALIZABLE]; 发布者:全栈程序员栈长,转载请注明出处:https://javaforall.cn/141565.html原文链接:https:/
_1 like db_table; 删除新表 drop table db_table_1 增加一列表 Alter table db_table add column name VARCHAR(40);...添加PRIMARY KEY(主键索引) ALTER TABLE `db_table` ADD PRIMARY KEY ( `name` ) 添加UNIQUE(唯一索引) ALTER TABLE `db_table...` ) 添加FULLTEXT(全文索引) ALTER TABLE `table_name` ADD FULLTEXT ( `column`) 添加多列索引 ALTER TABLE `table_name...name FROM db_test.db_table_copy1); 修改字段的长度 alter table app_info modify column mappingPath...4.串行化(Serializable ): 可避免 脏读、不可重复读、幻读 的发生。
支持状态 说明 视图相关语句 CREATE VIEW 支持 ALTER.../drop event均不支持 ALTER EVENT 限制支持 垂直库场景下支持...REPEATABLE READ,READ COMMITTED,SERIALIZABLE XA 模式只支持REPEATABLE READ、SERIALIZABLE SHOW语句 语句类型 SQL语句 支持状态...,DB.TABLE_NAME2...]...:test_db2 5.7.35 04:54:03> begin; Query OK, 0 rows affected (0.01 sec) root@192.168.171.22:test_db2 5.7.35
其主要命令有CREATE,ALTER,DROP等,下面用例子详解。该语言不需要commit,因此慎重。...CREATE – to create objects in the database 在数据库创建对象 例:CREATE DATABASE test; // 创建一个名为test的数据库 ALTER...– alters the structure of the database 修改数据库结构 例:ALTER TABLE test ADD birthday date; // 修改test表,新增...比如我们首先新建一个表:test test.sql SET NAMES utf8; SET FOREIGN_KEY_CHECKS = 0; -- --------------------------...conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE); Statement
我们常常听到一些关于MySQL的说法,比如“读不加锁”,比如“单表数据要小于1000万”,比如“DDL会锁表”等,比如“单表的索引数量应该小于X个”,如果不加思考和测试就直接全盘接受,就可能犯错误,而DB...开始查询事务后,以下DDL语句会被阻塞: DROP TABLE t; ALTER TABLE t ...; LOCK TABLE t ......Serializable隔离级别 注意上面引文中的最后一句话,MVCC与Serializable隔离级别不兼容,Serializable下会对所有读取的行加锁,读不加锁不再成立!...我们使用sysbench压测,来对比RC和Serializable隔离级别的性能表现: 压测命令: sysbench --test=oltp --oltp-table-size=100000 --mysql-db...***************** waiting_trx_id: F64AEF1 waiting_thread: 96090370 waiting_query: UPDATE sbtest set
' *.compatible='11.2.0.0.0' *.control_files='+FRA','+FRA' *.db_block_size=8192 *.db_create_file_dest=...'+FRA' *.db_domain='' *.db_name='lhrrac1' *.db_recovery_file_dest='+FRA' *.db_recovery_file_dest_size...set newname for datafile 6 to "+FRA"; set newname for tempfile 1 to "+FRA"; SQL "ALTER DATABASE...=8192 *.db_create_file_dest='/u01/app/oracle/oradata/lhrfs' *.db_domain='' *.db_name='lhrrac1' *.db_recovery_file_dest...set newname for tempfile 1 to "/u01/app/oracle/oradata/lhrfs/temp01.dbf"; SQL "ALTER DATABASE RENAME
主库参数 alter system set log_archive_config='DG_CONFIG=(xkdb,xkdg)' scope=both sid='*'; alter system set...,PRIMARY_ROLE) DB_UNIQUE_NAME=xkdg' scope=both sid='*'; alter system set standby_file_management=auto...scope=both sid='*'; alter system set fal_client='tnsxkdb' scope=both sid='*'; alter system set fal_server...db_name='XKDB' set db_unique_name='xkdg' set db_create_file_dest='+DG_DATA' set db_create_online_log_dest...=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=xkdb' set control_files='+DG_DATA' set db_file_name_convert
not exists db2; -- 需求: 创建名称为db3数据库,并指定字符集为gbk create database db3 character set gbk; 示例如下: -- 创建名称为...- 需求:将db3数据库的字符集改成utf8 alter database db3 character set utf8; -- 注意:utf8没有中间的横杠 示例如下: -- 查看当前数据库的字符集为...---------+ 1 row in set (0.00 sec) -- 修改db3的字符集为 utf8 mysql> alter database db3 character set utf8;...(0.00 sec) mysql> 2.3.6 修改字符集 ALTER TABLE 表名 character set 字符集; -- 需求:将stu表的字符集修改为gbk, 再将其修改回来 alter...table stu character set gbk; alter table stu character set utf8; 执行如下: -- 查看stu当前的表结构 mysql> show create
=+DATA VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=ORCL'; ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='...SET LOG_ARCHIVE_DEST_STATE_2=ENABLE; ALTER SYSTEM SET LOG_ARCHIVE_FORMAT='%t_%s_%r.arc' SCOPE=SPFILE...; ALTER SYSTEM SET LOG_ARCHIVE_MAX_PROCESSES=4; ALTER SYSTEM SET REMOTE_LOGIN_PASSWORDFILE=EXCLUSIVE...SCOPE=SPFILE; ALTER SYSTEM SET FAL_SERVER=ORCLDG; ALTER SYSTEM SET FAL_CLIENT=ORCL; ALTER SYSTEM SET...DB_FILE_NAME_CONVERT='/oradata','+DATA' SCOPE=SPFILE; ALTER SYSTEM SET LOG_FILE_NAME_CONVERT='/oradata
解决方法 1.先进入数据库面板,点击SQL运行下列语句(粘贴SQL语句执行即可): SQL语句 alter table typecho_comments convert to character set...utf8mb4 collate utf8mb4_general_ci; alter table typecho_contents convert to character set utf8mb4 collate...utf8mb4_general_ci; alter table typecho_fields convert to character set utf8mb4 collate utf8mb4_general_ci...; alter table typecho_metas convert to character set utf8mb4 collate utf8mb4_general_ci; alter table...::set($db);[/card]
) DB_UNIQUE_NAME=ORCL_STBY'; ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=ENABLE; ALTER SYSTEM SET LOG_ARCHIVE_FORMAT...SYSTEM SET DB_FILE_NAME_CONVERT='/oradata/ORCL','/oradata/ORCL_STBY' SCOPE=SPFILE; ALTER SYSTEM SET...SYSTEM SET DB_FILE_NAME_CONVERT='/oradata/ORCL_STBY','/oradata/ORCL' SCOPE=SPFILE; ALTER SYSTEM SET...1、主库开启闪回,防止Failover后无法再次切回备库 alter database flashback on; alter system set db_recovery_file_dest='/u01...FLASHBACK ON; --配置闪回参数 alter system set db_recovery_file_dest='/u01/app/oracle/fast_recovery_area'
string db_recovery_file_dest_size big integer 0 SQL> alter system set db_recovery_file_dest_size...SQL> alter system set db_recovery_file_dest='/u01/app/oracle/product/11.2.0/db_1/dbs/arch'; System altered...alter system set db_unique_name='jyzhao' scope=spfile; alter system set log_archive_config='DG_CONFIG...DB_UNIQUE_NAME=jyzhao_s' scope=spfile; alter system set log_archive_format='arch_%r_%t_%s.arc' scope...=spfile; alter system set fal_server=jyzhao_s scope=spfile; alter system set fal_client=jyzhao scope
在DB Link目标端定义一个存储过程用于触发10046。 1.1. 事先在DB Link目标端的远程数据库上,赋予登录用户 alter session权限。...在DB Link目标端定义一个存储过程 例: CREATE OR REPLACE PROCEDURE set10046trace as BEGIN execute immediate 'alter...session set timed_statistics=true'; execute immediate 'alter session set max_dump_file_size = UNLIMITED...'; execute immediate 'alter session set tracefile_identifier =''10046'''; execute immediate 'alter...PROCEDURE end10046trace as BEGIN execute immediate 'alter session set events ''10046 trace name