Exports and Snapshot Too Old Warning 1

[tekdudedude]

Hello,

I am attempting to export a large Oracle 9 database in preparation to migrate it to 10g. During the export I get a "snapshot too old" warning. My export continues and eventually completes.

Does this warning in any way affect my export file?

My export parameters:

buffer=2000000 compress=n direct=y grants=y full=y feedback=1000 indexes=y statistics=none

Full warning message:

EXP-00056: ORACLE error 1555 encountered
ORA-01555: snapshot too old: rollback segment number 3 with name "_SYSSMU3$" too small

Thanks,

TD

 

[SantaMufasa]

TekDude²,

There is a lengthy explanation in faq759-4436 of both the cause and resolution of the "Snapshot too old..." issue.

Another, simpler resolution that is use now is to simply increase the size (and optimal) of all rollback segments. (I, personally, find 200MB a healthy size to avoid this problem.) If you use the "resizing" alternative, and if you still encounter the error, then my suggestion is to then increase the size of each rollback segment by 100MB until the problem disappears completely.

Some people say that they prefer using Oracle's resolution to the "Snapshot..." problem by using UNDO (instead of Rollback) segments. I find that the often-"runaway" nature of UNDO segments highly undesirable...But that's just my opinion.

Let us know what you decide and your findings.

Mufasa
(aka Dave of Sandy, Utah, USA)
[I provide low-cost, remote Database Administration services: www.dasages.com]

 

[tekdudedude]

SantaMufasa,

Thanks for making that less confusing.

TD