oracle 教程http://www.cuug.com/一.SQL*PLUS中输入SQL> conn as sysdba;SQL> alter system setjob_queue_processes = 6; --自动执行数据收集时该参数需要大于0SQL> alter system set timed_statistics =true; --使用statspack收集统计信息时建议...【阅读全文】
When loading objects and data into the buffer cache of the instance there is a functionality which determines the best way to load for full scans. This functionality is called smallness logic and is driven by a hidden parameter called:_small_table_threshold.If the number of blocks to be read is lowe【阅读全文】
Beginning
with Oracle10G, when statistics are gathered for a table, the old statistics are
retained so should there be any problem with performance of queries dependent
on those statistics, the old ones can be restored.How
long does Oracle retain the statistics for ?
The
default peri【阅读全文】