sql - ORA-12801: error signaled in parallel query server P004 and ORA-01555: snapshot too old -

sql - ORA-12801: error signaled in parallel query server P004 and ORA-01555: snapshot too old -

i executing insert ... select ... ... ... sql , got next error using oracle:

java.sql.sqlexception: ora-12801: error signaled in parallel query server p004 ora-01555: snapshot old: rollback segment number 32 name "_syssmu32_2039035886$" little

i read next doc: http://www.dba-oracle.com/t_ora_12801_parallel_query.htm , http://www.dba-oracle.com/t_ora_01555_snapshot_old.htm

saying ora-12801 caused no plenty processors back upwards parallel query. ora-01555 error relates insufficient undo storage or little value undo_retention parameter.

but how can check related parameters avoid such issue recur?

from the manual:

ora-12801: error signaled in parallel query server string

cause: parallel query server reached exception condition.

action: check next error message cause, , consult error manual appropriate action.

this generic error message , never has not plenty processors. illustration of how site linked contains lots bad or outdated information. maybe 17 processes "a lot" 17 years ago, it's not today. unfortunately, site first result google.

you can check undo retention, amount of time in seconds, this:

select value v$parameter name = 'undo_retention'

once again, see the manual more info on parameter.

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