1.如何查看sequence的定义
2.dba_sequences相关字的定义
3.如何修改sequence
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1.如何查看sequence的定义
SQL>SELECT DBMS_METADATA.GET_DDL(‘SEQUENCE‘,‘SEQ_SMECUSTPERIODINFO‘,‘CLMS01‘) FROM DUAL;
CREATE SEQUENCE "CLMS01"."SEQ_SMECUSTPERIODINFO" MINVALUE 1 MAXVALUE 999999
9999 INCREMENT BY 1 START WITH 8798675575 CACHE 20 ORDER NOCYCLE --START WITH 8798675575 此值为dba_sequneces中的LAST_NUMBER，比较奇怪！！
2.dba_sequences相关字的定义
| Column | Datatype | NULL | Description |
|---|---|---|---|
SEQUENCE_OWNER |
VARCHAR2(30) |
NOT NULL |
Owner of the sequence |
SEQUENCE_NAME |
VARCHAR2(30) |
NOT NULL |
Sequence name |
MIN_VALUE |
NUMBER |
Minimum value of the sequence | |
MAX_VALUE |
NUMBER |
Maximum value of the sequence | |
INCREMENT_BY |
NUMBER |
NOT NULL |
Value by which sequence is incremented |
CYCLE_FLAG |
VARCHAR2(1) |
Indicates whether the sequence wraps around on reaching the limit (Y) or not (N) |
|
ORDER_FLAG |
VARCHAR2(1) |
Indicates whether sequence numbers are generated in order (Y) or not (N) |
|
CACHE_SIZE |
NUMBER |
NOT NULL |
Number of sequence numbers to cache |
LAST_NUMBER |
NUMBER |
NOT NULL |
Last sequence number written to disk. If a sequence uses caching, the number written to disk is the last number placed in the sequence cache. This number is likely to be greater than the last sequence number that was used. |
- CYCLE_FLAG：标志sequence是否循环使用（到最大值之后变为最小值）
- ORDER_FLAG：标志sequence是否是按照顺序生成。
- CACHE_SIZE：标志内存中缓存的sequence个数（保存在shared pool中），设置较小时会出现row cache lock的等待事件。
- LAST_NUMBER：不太好理解。
3.如何修改sequence
原文地址：https://www.cnblogs.com/dayu-liu/p/8794727.html