Shulou(Shulou.com)06/01 Report--

Insert inserts data Times error:

SCOTT@prod > insert / * + append * / into scott.employee select * from scott.employee; 3584 rows created.SCOTT@prod > / insert / * + append * / into scott.employee select * from scott.employee * ERROR at line 1:ORA-12838: cannot read/modify an object after modifying it in parallel

View table parallelism

SQL > select a.degree from dba_tables a where a.tableroomnameplate EMPLOYEE1

View lock information

SELECT o.object_name, o.owner, l.locked_mode, s.sid, s.serializations, s.logon_time FROM v$locked_object l, dba_objects o, v$session s WHERE l.object_id = o.object_id AND l.session_id = s.sid AND o.object_name = 'EMPLOYEE' OBJECT_NAME OWNER LOCKED_MODE SID SERIAL# LOGON_TIME--EMPLOYEE SCOTT 6 80 5328 2019-11-24

Ora-12838 error

SCOTT@prod >! oerr ora 1283812838, 00000, "cannot read/modify an object after modifying it in parallel" / / * Cause: Within the same transaction, an attempt was made to add read or / / modification statements on a table after it had been modified in parallel// or with direct load. This is not permitted.// * Action: Rewrite the transaction, or break it up into two transactions:// one containing the initial modification and the second containing the// parallel modification operation.

Append will insert data above the high water level and generate less redo data, and will hold an exclusive lock while accelerating the insertion speed, which can easily cause this problem for uncommitted transactions after execution.

MOS related documents

ORA-12838 with Direct Load Inserts (document ID 116494.1) PARALLEL RESTRICTIONS:A transaction can contain multiple parallel DML statements that modilydifferent tables, but after a parallel DML statement modifies a table,NO subsequent serial or Parallel statment (DML or QUERY) can access thesame table again in that transaction.***Each insert in SQL*plus is considered a transaction, while the wholePL/SQL BLOCK is considered a transation.

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