SQL> 1. 上面time_waited、average_wait的单位为百分之一秒(in hundredths of a second), 'log file parallel write'事件的平均等待时间大于 10ms (or 1cs),这通常意味着存在较慢的I/O吞吐量。 LGWR进程写入慢会影响用户事务提交的时间。 If the log file parallel write average wait time is greater tha...
但是就有这样的矛盾存在:在内存资源有限的情况下,某些时候数据被cache的需求非常大,为了提高buffer hit,就需要增加Buffer Cache,但由于SGA有限,只能从其他区“抢”过来——如缩小Shared Pool,增加Buffer Cache;而有时又有大块的PLSQL代码被解析驻入内存中,导致Shared Pool不足,甚至出现4031错误,又需要扩大Shared Pool...
select count(*),count(NVL(comm,0)) from emp; ③使用group by子句数据分组 select deptno,avg(sal) from emp group by deptno; 注意:在select列表中所有未包含在组函数中的列都应该包含在group by子句中 包含在group by子句中的列不必包含在select列表中 ④使用having子句过滤分组结果集 不能再where子句中使...
I am having a hard time with what should be a simple query. I have studied the documentation on the AVG function and understand that I may need to execute this with a subquery. This is the gist of what I want to accomplish - finding values greater than 3 * the ...
InAnswers, advanced users and developers can use the Advanced SQL Clauses fields in the Advanced tab of the Analysis editor to specify various SQL clauses such asGROUP BY,HAVING, andDISTINCT, to include in the SQL queries that are sent to theOracle BI Server. If an analysis contains hierarc...
Members of the OSASM group can use SQL to connect to an Oracle ASM instance as SYSASM using operating system authentication. The SYSASM privilege that was introduced in Oracle ASM 11g release 1 (11.1) is now fully separated from the SYSDBA privilege in Oracle ASM 11g Release 2 (11.2). SY...
Oracle Database SQL Referencefor more information about using theTABLEsyntax. Storage Considerations for Varrays The size of a stored varray depends only on the current count of the number of elements in the varray and not on the maximum number of elements that it can hold. Because the storage...
One of the biggest obstacles to benefiting from your investment in big data is not having enough staff with the necessary skills to analyze your data. You can mitigate this risk by ensuring that big data technologies, considerations, and decisions are added to your IT governance program. Standard...
Ora2Pg is a free tool used to migrate an Oracle database to a PostgreSQL compatible schema. It connects your Oracle database, scan it automatically and extracts its structure or data, it then generates SQL scripts that you can load into PostgreSQL. - dar
1 Did you try just this? <property name="Name" length="10000" not-null="true" /> I'm using SQL Server and I don't need to specify a type in such a case. Share Follow answered Mar 23, 2012 at 7:40 Stefan Steinegger 64.5k1717 gold badges130130 silver badges193193 bronze ...