如果您的数据库版本支持，请使用identity列，并让Oracle为您生成值;在背景中，它仍然是一个序列 ...
3.多个会话使用sequence可能出现争用,等待事件row lock contention 对于nocache/cache參数: nocache:每次使用nextval,都会更新Seq$基表并COMMIT。 cache:仅仅有在内存中cache的序列号使用完后才会又一次获取sequence。才会更新Seq$基表并提交。 比方cache设置为2000,则在使用sequence时对性能影响比nocache小上千倍。 所以...
ORA-02287: sequence number not allowed hereThere are also cases where adding a sequence to the select list has a much greater effect than just being “another column.” Distributed queries, for example, may change their execution plan quite dramatically because the addition of a sequence has cha...
3. In the Staging Lanes region, Number field, enter a sequence number that represents the proximity of the staging lane to the dock door. When selecting a staging lane, Oracle Warehouse Management will select an available staging lane in the order of the sequence indicated here. 4. In the ...
maxLimit (maximum number of connections allowed by this cache) minLimit (minimum number of connections existing for this cache) If you are using fewer than this number, then there will also be connections in the "idle pool" of the cache. stmtCacheSize (cache size for Oracle JDBC statem...
Here's the data import command:复制 psql -f %namespace%\data\table1.sql -h server1-server.postgres.database.azure.com -p 5432 -U username@server1-server -d database -l %namespace%\data\table1.log psql -f %namespace%\data\table2.sql -h server1-server.postgres.database.azure....
ORA-01449: 列包含 NULL 值;无法将其改变为 NOT NULL ORA-01450: 超出最大的关键字长度 () ORA-01451: 要修改为 NULL 的列无法修改为 NULL ORA-01452: 无法 CREATE UNIQUE INDEX;找到重复的关键字 ORA-01453: SET TRANSACTION 必须是事务处理的第一个语句 ...
It's important to specify the USING BACKUP CONTROLFILE syntax to inform the RECOVER AUTOMATIC DATABASE command that recovery should not stop at the Oracle system change number (SCN) recorded in the restored database control file.The restored database control file was a snap...
ORA-00001: 违反唯一约束条件 (.) ORA-00017: 请求会话以设置跟踪事件 ORA-00018: 超出最大会话数 ORA-00019: 超出最大会话许可数 ORA-00020: 超出最大进程数 () ORA-00021: 会话附属于其它某些进程;无法转换会话 ORA-00022:
Oracle Database - Enterprise Edition - Version 12.1.0.2 and later: Upper Limit For the Oracle Sequence Number