通常出现性能问题后dba才会去用outline进行调优。 Hint和outline称为plan stability技术。由于上面提到的缺点,oracle10g开始引入了一些新的技术。 2.3 Sql Profile 关于sql的补充信息,保存在数据字典中,用来帮助优化器选择执行计划。(可以这么理解,sql的profile,相当于table/index的optimizer statistics) 2.4 SQL Pan Baseli...
(On the SQL Profiler menu, select File, Open, Trace Definition; or, in the Trace Name drop-down list, select the Edit Trace Properties button, then select Sample 1 – TSL.) This basic trace doesn't show any information that a SQL Server 6.5 DBA couldn't get with SQL Trace, but its...
Summary_<MachineName>_YYYYMMDD_HHMMss.txt 文件 Detail.txt 文件 MSI 日志文件 显示另外 5 个 适用于:SQL Server- 仅限 Windows 默认情况下,SQL Server 安装程序会在 %programfiles%\Microsoft SQL Server\nnn\Setup Bootstrap\Log 内带有日期和时间戳的文件夹中创建日志文件,其中 nnn 是与正在安装的 SQL 版本...
mysql> show profile block io,cpu,memory,source for query 1; profile执行耗时详情 从profile执行结果中,我们可以清晰的看到一条SQL在每个执行阶段的耗时、CPU使用率、IO等指标,帮助我们定位到慢查询具体执行耗时的阶段,对于该条SQL,执行过程中最耗时的部分是executing部分,executing阶段包括了执行线程正在为SELECT读取...
史上最全近百条Oracle DBA日常维护SQL脚本指令 查询碎片程度高(实际使用率小于30%)的表 可以收缩的表条件为什么block>100,因为一些很小的表,只有几行数据实际大小很小,但是block一次性分配就是5个(11g开始默认一次性分配1M的block大小了,见create table storged的NEXT参数),5个block相对于几行小表数据来说就相差...
Summary_<MachineName>_YYYYMMDD_HHMMss.txt 文件 Detail.txt 文件 MSI 日志文件 显示另外 5 个 适用于:SQL Server- 仅限 Windows 默认情况下,SQL Server 安装程序会在 %programfiles%\Microsoft SQL Server\nnn\Setup Bootstrap\Log 内带有日期和时间戳的文件夹中创建日志文件,其中 nnn 是与正在安装的 SQL 版本...
from DBA_HIST_SYSMETRIC_SUMMARY t where t.metric_name in ('Physical Read IO Requests Per Sec', 'Physical Write IO Requests Per Sec', 'Redo Generated Per Sec', 'Physical Read Bytes Per Sec', 'Physical Write Bytes Per Sec', 'DB Block Changes Per Sec', ...
Backups (and the related technologies discussed earlier) are certainly the most important part of a high-availability strategy if only a single instance of SQL Server 2008 can be employed. However, there are other technologies that can enhance the ability of the DBA to maintain high-availability...
Please note that -m starts SQL Server in single-user mode and is meant to allow a DBA to start the database and make changes to the SQL Server Audit configuration if necessary. Alternatively, the -f trace flag can be used to start SQL Server in minimal configuration mode, in which case...
SQL Server Audit itself will not be deactivated and only the shutdown behavior will be disabled. Please note that-mstarts SQL Server in single-user mode and is meant to allow a DBA to start the database and make changes to the SQL Server Audit configuration if necessary. Alternatively, the...