5、到了1点45分,用户A的查询终于到了第4100万行,而这时已经出现了第4条说的情况,需要到回滚段UNDOTS1去找数据,但是已经被覆盖掉了,这时就出现了ORA-01555错误。 原因分析:"报表"程序执行时间漫长,在程序查询的过程中其他用户对"报表"进行了更新,被更新的数据写入了回滚段,当程序到回滚段找数据时,发现数据已...
一、引言: [oracle@yft yft]$ oerr ora0155501555,00000, "snapshot too old:rollback segmentnumber%swith name \"%s\" too small"//*Cause:rollback records neededby a readerfor consistentreadare// overwrittenbyother writers//*Action:IfinAutomatic Undo Management mode, increase undo_retention// set...
ORA-01555: snapshot too old 在大型OLAP系统中运行查询经常会遭遇“ORA-01555: snapshot too old”的错误。这是因为Oracle为了保持读一致性,需要从回滚段中读取被修改的记录,但是同时这条被修改的记录在回滚段中却找不到了。这时,就会报错“ORA-01555: snapshot too old”。实验思路: 1. 创建大小为1M的回滚...
01555, 00000, "snapshot too old: rollback segment number %s with name \"%s\" too small" // *Cause: rollback records needed by a reader for consistent read // are overwritten by other writers // *Action: If in Automatic Undo Management mode, increase ...
ORA-01555: snapshot too old: rollback segment number with name "" too small 0 Error java.sql.SQLException: ORA-01555 1 Does the function inside the Select clause evaluate the passed in columns before the where clause? 0 How to commit transaction on an after update event ...
ORA-01555: snapshot too old: rollback segment number 9 with name “_SYSSMU1$” too small Alert.log中显示: ORA-01555 caused by SQL statement below (Query Duration=9999 sec, SCN:0x000.008a7c2d) 其次,通过alert.log确定QUERY DURATION。上例中为9999秒。
ORA-01555的直观解释是“snapshot too old”,也就是快照太旧,其根本含义就是查询需要的前镜像过于“久远”,已经无法找到了。可以想象,如果一个历时数个小时或十几个小时的查询,如果最后遭遇ORA-01555错误而失败,会是多么令人沮丧的一件事。一直以来,ORA-01555都是ORACLE最为头痛的问题之一。
ORA-01555: snapshot too old: rollback segment number 6 with name "_SYSSMU6_12 The error might occur only in the application log, but not necessarily in the alert file. There may or may not be a current SQL reported in the incident trace file: --- Error Stack Dump --- ORA-01555:...
oracle-ORA-01555错误 Snapshot too old 原因:没有足够的撤销空间满足读一致性而需要撤销信息的长查询