dump roll back segment too small

[Former Member]

Hii All,

From last week i am getting this dump in my production system.

Database error text........: "ORA-01555: snapshot too old: rollback segment

number 20 with name "PRS_18" too small#"

Internal call code.........: "[RSQL/FTCH/MKPF ]"

What should i do to avoid this dump.

Regards,

Viren.

[Former Member · Accepted solution]

HI Rana,

When you have "ora-01555: snapshot too old (rollback segment _ too small)", it usually means failure due to the lack of rollback space. The failure indicates read consistency error, as your active transaction overwrites existing, uncommitted transaction, which implies that the system change number SCN in the block is newer than the SCN at the start of the transaction. The read consistency image of new data can therefore not be created. This can happen when large transactions are being written where there is not enough tablespace for the rollback segments to expand or when the rbs has reached its "MAXEXTENTS".

Solution is to either add new roll back segment or extend the size of the existing ones.To extend the size of existing ones, increase both the values of their MINEXTENTS and OPTIMAL parameters with ALTER ROLLBACK SEGMENT statement or create additional ones.

Thanks

Prince Jose