所以说pctfree是控制什么时候将块从freelist中移除的。 pctused这个参数控制一个块什么时候被重新启用来插入数据,例如当一个块达到1-pctfree利用率的时候,oracle停止向该块插入数据,同时从freelist移除该块,但是后来发生一些删除操作,使得该块的利用率下降,当该块的利用率降到pctused以下的时候该块就被重新启用来插入...
用CREATE命令的PCTUSED、PCTFREE、INITTRANS、MAXTRANS、 FREELISTGROUPS和FREELISTS参数来控制表、索引或簇的数据块中的空间 使用。 可使用PCTFREE和PCTUSED参数控制数据块何时进入或离开表、索引或簇的 ...
INITRANS表示块首部中事务表的初始大小,该值影响着对表的事务并发访问(表默认是1,索引默认是2);MAXTRANS表示事务表的 最大值,Oracle10g中默认值是255。 附oracle官方文档关于PCTUSED参数解释: ThePCTUSEDparameter sets the minimum percentage of a block that can be used for row data plus overhead before new ...
After a data block becomes full as determined by PCTFREE, Oracle does not consider the block for the insertion of new rows until the percentage of the block being used falls below the parameter PCTUSED. Before this value is achieved, Oracle uses the free space of the data block only for ...
to existing rows in the block PCT_USED 是这么样个参数: 这个参数用来控制什么时候该block可以重新insert数据。 比如这个值是: PCT_USED=40,当block里面的数据delete到低于40%的时候,比如是这个block只有39%的空间有数据,那么这个时候就开始可以接受新的数据。
PCTUSED参数设置最小的数据块百分比用于行数加上消耗。直到达到这个值,ORACLE 使用数据块的空闲空间仅用于更新在已经包含于的数据块。比如,假定设定了以下参数在 CREATE TABLE 语句: PCTUSED 40 In this case, a data block used for this table’s data segment is considered unavailable ...
Currently the metric used_pct_max for the tablespaces in the Zabbix Agent 2 Oracle plugin returns the allocated and not the used percentage of the tablespace. Please change the sql statement to something like this: old: ROUND(DECODE(SUM(df.MAX_BYTES), 0, 0, (SUM(df.BYTES) / SUM(df.MA...
A specially created agent LWP is used to execute these system calls in the controlled process. See proc(4) for more details. While executing the event handler functions, the library arranges for the signals SIGTERM, SIGQUIT, SIGABRT, and SIGINT to be blocked to reduce the likelihood of a ...
A specially created agent LWP is used to execute these system calls in the controlled process. See proc(4) for more details. While executing the event handler functions, the library arranges for the signals SIGTERM, SIGQUIT, SIGABRT, and SIGINT to be blocked to reduce the likelihood of a ...
Oracle Server Enterprise Edition - Version: 9.0.1.4 to 9.2.0.8 Goal The Purpose of this Note Is To explain the behavior of PCTVERSION and RETENTION in LOB Segments.The Following Example shows the issue. Create a LOB specifying PCTVERSION = 5 and create another one specifying RETENTION. When ...