2.网络往返次数由之前的6611次下降到只需要1984次。 需要注意的是这些改变都是与SQL语句本身无关的,Arraysize大小需要通过编程实现,本例中使用SQL*Plus环境中的SET ARRAYSIZE命令,如果是Java应用,可以通过设置Connection.SetdefaultRowPrefetch(n)来实现。
An array prefetch system (200) improves processor performance by automatically tuning a statically compiled and compacted loop program at run-time to accommodate variations in latency of memory read operations. Using the array prefetch system, the processor, while awaiting completion of a data access,...
rowprefetch,(floor(rowprefetch/arraysize)+1)*arraysize,(floor(rowprefetch/arraysize)+1)*arraysize,...,剩下的记录. --//注:我当时测试时忽略了rowprefetch=arraysize的情况.使用floor代替ceil才是正确的. 2.显示行数量规律: --//而显示记录时看到的情况并不对应fetch的记录数量.以前的分析有误.仅仅需...
This affects prefetch scheduling. As in affine array prefetching, the computation of the prefetch distance uses Equation 3.2. However, the adjustment of array indices for indexed arrays must take into consideration the serialization of data and index array references. Since data array elements cannot ...
The RAID controller card prefetches sequential data or the data predicted to be used and saves it in the cache. NOTE: To achieve optimal drive performance, set the read policy to Read Ahead for HDDs and No Read Ahead for SSDs. Write Policy Specifies the write policy of the virtual ...
array_walk函数是PHP中一个非常有用的函数,它可以在数组中的每一个元素上运行用户自定义的函数。每个数组元素都会被传递到回调函数中,函数可以直接修改原数组的元素值。array_walk函数的两个基本参数是一个数组和一个回调函数。
matlab.data.arraytype.html 错误与 MATLAB 运行时发生的问题有关。通常,HTML 错误是由丢失或损坏的文件引起的。了解如何下载和替换正确版本的 matlab.data.arraytype.html 并修复这些令人讨厌的 HTML 错误消息。
例如，在OCCI中设置这个参数的函数是：setPrefetchRowCount()。做个简单的实验：create table t as select * from all_objects;set autotrace traceonly statistics;set arraysize 2 select * from t;统计信息 --- 288 recursive calls 0 db block gets 25300 consistent gets 682 physical read...
3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm...
An array prefetch system improves processor performance by automatically tuning a statically compiled and compacted loop program at run-time to accommodate variations in latency of memory read operations. Using the array prefetch system, the processor, while awaiting completion of a data access, continue...