oracle commit wait

One. DB file Parallel Write wait eventQuote from the following blog:Http://oradbpedia.com/wiki/Wait_Events_-_db_file_parallel_writeDB file Parallel writeThe db file parallel write wait event belongs to the Oracle database writer (DBWR) process because it is the only process that writes blocks from the SGA to the data file. When it is written, the DBWR process com

to the rollback completion.If you wait too much, it may indicate that the LGWR writing is inefficient, or that the system commits too often.For this issue, you can focus on:Log file parallel write wait eventStatistics such as user Commits,user rollback can be used to observe commit or rollback timesSolution:1. Improve LGWR PerformanceTry to use a fast disk and d

In 11.2, materialized view logs also add features that, for local materialized views, can now be refreshed using the commit SCN instead of the timestamp method in the previous version. Look at a simple example: Sql> SELECT * from V$version; BANNER -------------------------------------------------------------------------------- Oracle database11genterprise Edition release11.2.0.1.0-64bit Production Pl/

1. COMMIT_FORM and COMMIT Both form and database are submitted. Submit the data changes in form to the background database, and submit the data in the database.2. DO_KEY ('commit _ form ') It will first execute the code in the KEY-COMMIT trigger. Without this trigger, it will perform the same operations as COMMIT_FORM.3. FORMS_DLL ('

Oracle 11g Create or replace procedure skeletonISBEGINBeginInsert into a values (10 );BeginInsert into a values (11 );End;End;Begin-- Savepoint ps;Insert into a values (20 );Commit;End;BeginInsert into a values (30 );End;Insert into a values (40 );-- Commit;Rollback;-- Rollback to ps;END; In oracle, begin end only serv

Oracle transaction row-Level Lock storage point rollback commit. Note that A and B are not two ORACLE accounts, but two connection sessions. The above is just Oracle transaction row-Level Lock storage point rollback commit. Note that A and B are not two

The materialized view log in 11.2 can specify the commit SCN, when materialized view refreshes do not require a timestamp, a simple description of how Oracle implements the refresh through the commit SCN. Establish a test environment: Sql> SELECT * from V$version; BANNER --------------------------------------------------------------------------------

All along, it is assumed that connection if Setautocommit (false) is set, the manual transaction commit must be initiated manually or rollback. There was a problem today and the results were very surprising.The results were tested as follows (note that under Oracle drivers, other environments are unknown):1, set the Setautocommit (false) after performing the subsequent DML data update operation, did not exp

Label:triggers cannot invoke or indirectly invoke a DCL statement such as Commit,rollback DDL statements and Commit,rollback statements cannot be run in triggers DDL statements: DDL statement terms define and manage objects in the database, such as Create,alter,drop,truncate, and DDL operations are implicitly committed!The operation takes effect immediately and the original data is not placed in the rollbac

Distributed transactions are transactions that occur between multiple databases, and in Oracle, transactions are handled in a dblink manner, and distributed transactions are much more complex than stand-alone transactions. Most relational databases complete distributed transactions through two-phase commit (2 Phase commit 2PC) algorithms, and the following 2PC al

Label:After the DML statement (update, INSERT, delete) is written, a manual commit is required, and if there is no commit, the updated content is saved in memory instead of being submitted to the database and will not be seen by the other session (Dialog). Other conversations see the data before the update. Oracle does not automatically

What Does oracle do when executing commit? COMMIT is a very fast operation. When we release the commit command, the really difficult action has been completed and the data changes have been executed in the database, therefore, 99% of the tasks have been completed. Www.2cto.com For example: The following operations have

Today in the operation of the database, found that the data operation error, want to recover, but no transaction, supposedly, set to not default commit transaction, at this time the various operations do not respond to the database. At this point, you can rollback the transaction and undo any uncommitted changes. However, once a commit is made, there is really no way to undo it. Fortunately,

1. COMMIT_FORM and COMMIT Both form and database are submitted. Submit the data changes in form to the background database, and submit the data in the database. 2. DO_KEY ('commit _ form ') It will first execute the code in the KEY-COMMIT trigger. Without this trigger, it will perform the same operations as COMMIT_FORM. 3. FORMS_DLL ('

the database by 0-6. Different SQL operations produce different types of TM locks. There is only an X lock (exclusive lock) on the data line. In an Oracle database, a TX lock is obtained when a transaction initiates a DML statement for the first time, and the lock remains until the transaction is committed orRoll back. When two or more sessions execute DML statements on the same record on a table, the first session is locked on that record, and the o

:0x0100019c Object ID on block? Y SEG/OBJ:0XCEF0 csc:0x00.c3cf8 itc:3 flg:e typ:1-DATA brn:0 bdba:0x1000199 ver:0x01 opc:0 inc:0 exflg:0 Itl Xid Uba Flag Lck SCN/FSC 0x01 0xffff.000.00000000 0x00000000.0000.00 C---0 SCN 0x0000.000c3cf8 0x02 0x0006.02b.000001a1 0x008000d0.00f6.2a----FSC 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00----0 FSC 0x0000.00000000 Here we can see that we lck the record in 10 tables This is when we use bbed to