checkpoint ngfw

up the database, and then restore the database, look at the restored backup set is not the same time you just back upIt's easy to draw a picture.--------------------------------------------------------------------------------------------------------------- -1 DBCC LOG ([Dlgpos])Here's the operation field in the transaction log, and the Operation field shows what the LSN is doing.For example: Lop_begin_ckpt,ckpt:checkpoint, if you see operation is LOP_BEGIN_CKPT, indicates that the LSN is doing

Transferred from: http://blog.sina.com.cn/s/blog_a32eff28010136d9.htmlLog or archive log to obtain data additions and deletions change, and then apply these changes to the target database, the source database and the target database synchronization, dual-live. GoldenGate TDM Software enables a large amount of data sub-second real-time replication between heterogeneous IT infrastructures, including almost all common operating system platforms and database platforms, with a simplified copy of the

LSN; This field 695 was defined only if a archived log 696 file has been completely written */697 #defin E log_checkpoint_1 os_file_log_block_size 698/* First CHECKPOINT field in the LOG 699 header; We write alternately to the checkpoint fields when we make new 701 checkpoints; This field was only defined 702 in the first log file of a log group */703 #define LOG_CHECKPOINT_2 (3 * os_fil e_log_block_size)

Introduction to Oracle Goldengate Learning goldengate (2012-10-02-17:07:27) Tags: checkpoint data transfer Queue process Category: Goldengate Goldengate IntroductionGoldenGate TDM (transaction data management) software is a log-based structured data replication software, which through the analysis of the source database online log or archive log to obtain data deletion and change, and then apply these changes to the tar

startupFor DNA, the Oracle database control file is a very important file, which is a binary file that is automatically generated when the database is created, which records the status information of the database. No other user can modify the control file, and the database instance may modify the information in the control file only while the database is running. The control file mainly includes the following content:Database name, a control file can belong to only one database.Database creatio

When Will instance recovery be generated after in-depth analysis of instance recovery? When your database server suffers an abnormal power failure, instance recovery will occur when you restart the database. Instance recovery is automatically completed by the database without DBA interference. Of course, there is a premise: data files, online log files, and control files must not be damaged. Let's use an experiment to analyze the whole process of instance recovery! 1. Before shutting down the da

background processes if necessary.· Register an Oracle instance with the Oracle TNS Listener 2.SMON: System Monitor(System Monitor)· Clear temporary space· Merge free spaceIf you are using a dictionary-managed tablespace, SMON is responsible for obtaining consecutive idle segments in the tablespace and merging them into a larger idle segment.· Recover the transaction for the original unavailable files: This is similar to the role of SMON when the database is started· Restore instances of failed

The principle of instance recovery when the database suddenly crashes, it is not time to refresh the dirty data blocks in the buffer cache to the data file, at the same time, when a transaction is suddenly interrupted when the instance crashes, the transaction is in the intermediate state, that is, neither commit nor rollback. At this time, the content in the data file cannot reflect the status of the instance crash. In this way, the closed database is inconsistent. The next time you start an in

Oracle architecture learning notes: the most important thing for oracledatabase is onlineredolog, ldquo; write rdquo;: Checkpoint Process computing workload to set checkpoints, Oracle architecture learning notes, the most important of oracle database is online redo log, ldquo; write rdquo;: Checkpoint Process computing workload, to determine the checkpoint,

not become the bottleneck of HDFS operations, hadoop adopts the following method: No snapshot of the current file system is persisted, the list of HDFS operations in the recent period will be saved to an editlog file in namenode. When the namenode is restarted, in addition to the load fsimage accident, the HDFS operation recorded in the editlog file will be replaced to restore the final state before the HDFS restart. Secondarynamenode periodically merges the HDFS operations recorded in the edi

1. Meta Data Management OverviewHDFs metadata, grouped by type, consists mainly of the following sections:1, the file, the directory of its own property information, such as file name, directory name, modify information and so on.2. Storing information about the information stored in the file, such as block information, block case, number of copies, etc.3, records the Datanode of HDFs information, for Datanode management.In the form of memory metadata and metadata files two, respectively, there

I. When do I need instance recovery? In shutdown normal or shutdown immediate, the so-called clean shutdown will automatically trigger the checkpoint and write the SCN record back. When a checkpoint occurs, the SCN is written to four places: Three places are in the control file: (1) SYSTEM CHECKPOINT SCN (2) Datafile checkpoi