checkpoint vsec

become a problem, it is necessary to first understand what sleep_bpool_flush this waiting state is. In Microsoft's official note: https://technet.microsoft.com/zh-cn/library/ms179984 (v=sql.105). aspx, with a simple description: When checkpoints abort new I/O to prevent disk subsystem flooding Appears at the time of publication. Obviously, this explanation is inadequate. So I turned over the foreign Daniel Blog and other books, summarized as follows:This wait state is directly related to the

I. Checkpoints theory description Checkpoints for Gg are described in the architecture of Series 1 and GG: Oraclegolden gate Series 1-GG architecture description Http://blog.csdn.net/tianlesoftware/article/details/6925907 Here we will explain it separately, because this is a more important concept. Checkpoints storethe current read and write positions of a process to disk for recovery purposes. these checkpoints ensure that data changes that are marked for synchronizationactually are extracted

,delete). SQL Server uses Write-ahead logging technology to ensure the atomicity and durability of transaction logs. This technology not only guarantees atomicity (A) and persistence (D) in acid, but also greatly reduces IO operations, The work of submitting changes to the data to disk is given to Lazy-writer and checkpoint. This article focuses on the process of SQL Server modifying data and related technologies. Pre-write log (Write-ahead Logging (W

many Oracle beginners have headaches due to the checkpoint knowledge point. The vast majority of Oracle documents describe full checkpoints and incremental checkpoints; for example, if the switching of online logs results in a full checkpoint or an incremental checkpoint, there is a lot of debate. In fact, there is a significant difference between an incremental

I. file type on p4server 0) file composition of p4server: 1) file types such: 2) All files in the depot directory and directory are actually submitted by the developer.CodeFile Information, we become versioned files; (Files in depot are in the RCS format, refer to: http://durak.org/sean/pubs/software/cvsbook/RCS-Format.html) For example, changlist: The corresponding files in depot are: versiontest.txt, V Head 1.75 ; Access ; Symbols ; Locks ; Comment @@

In the implementation of InnoDB engine, the redo log system is built in order to realize the persistence of the transaction. The redo log consists of two parts: the Memory log buffer (redo log buffers) and the redo log file. The purpose of this design is obvious: The log buffers are designed to speed up the logging, and redo log files provide persistence for log data. In InnoDB's redo log system, the following concepts have been introduced in order to achieve better log recoverability, security,

DBWR to write. If a timeout occurs (3 seconds each time), DBWR notifies itself. When a checkpoint occurs, LGWR notifies DBWR. In the first two cases, DBWR dirty blocks in the table are written to the disk, with each writable block specified by the initialization parameter DB-BLOCK-WRITE-BATCH. If the dirty table does not have a buffer with the specified number of blocks, DBWR looks for another dirty buffer from the LUR table. If DBWR is not active wi

/50455543Introduction: Since this has become a problem, it is necessary to first understand the waiting status of SLEEP_BPOOL_FLUSH. In Microsoft official note: https://technet.microsoft.com/zh-cn/library/ms179984 (v = SQL .105). aspx, only a simple description: when a checkpoint suspends a new I/O release to avoid disk subsystem flooding. Obviously, this explanation is insufficient. Therefore, I have rummaged through the blogs and other books of Dani

In the previous article we explored the role of zookeeper in Flink fault tolerance (storing/recovering completed checkpoints and checkpoint number generators).This article will talk about a special checkpoint that Flink named--savepoint (savepoint).Because the savepoint is just a special checkpoint, there is not much code implementation in Flink. But as a feature

2008R2. Source: http://blog.csdn.net/dba_huangzj/article/details/50455543Introduction: Since this has become a problem, it is necessary to first understand the waiting status of SLEEP_BPOOL_FLUSH. In Microsoft official note: https://technet.microsoft.com/zh-cn/library/ms179984 (v = SQL .105). aspx, only a simple description: When a checkpoint suspends a new I/O release to avoid Disk Subsystem flooding. Obviously, this explanation is insufficient. The

Goldengate upgrade from 11.2 to 12.1.21. Stop the extraction process Ggsci (001.oracle.drs.dc.com) 286> stop EXTSJ01 2. Stop the post and copy processWait for the delivery process to finish transferring and the copy process has finished loading. When the write Checkpoint of the delivery process is the same as the sequence and RBA of the current Checkpoint, the synchronization is c

Enter view the number of fields in the table in the current library: Mediumint (6) [Root@db-master ~]# SH alter_table.sh ALTER TABLE USER_CAMPAIGN_0 Modify Current_stage mediumint (6) unsigned NOT null default 0 comment ' current checkpoint '; 0 finished. ALTER TABLE user_campaign_1 Modify Current_stage mediumint (6) unsigned NOT null default 0 comment ' current checkpoint '; 1 finished. ALTER TABLE u

, it is necessary to do etrollover operationsGgsci>alter Extract ExttretrolloverGgsci>alter Extract Dpetretrollover3.5 Modifying the source-side DataPump process extseqno and Extrba numbersBecause the extract-exttr process on the source side performs the etrollover operation, the Extseqno and Extrba of the process are reset to the No. 0 extseqno of the next Extrba number, And DataPump did not know that the extract process took place this change, still watch in extract etrollover before the extse

MySQL series: innodb source code analysis-redo log structure, mysqlinnodb In innodb Engine implementation, a redo log system is built to ensure transaction persistence. Redo log is composed of two parts: the memory log buffer and the redo log file. The purpose of this design is obvious. The log buffer is to speed up log writing, and redo log files to provide persistence for log data. In the innodb redo log system, the following concepts are introduced in order to better achieve log recoverabilit

parameter Db-block-write-batch.When a server process looks for the db-block-max-scan-cnt buffer in the LRU table, it does not find the unused buffer, it stops finding and notifies DBWR to write. A timeout (3 seconds per time) occurs and DBWR notifies itself. When a checkpoint occurs, LGWR notifies DBWR. In the first two cases, DBWR writes the block in the dirty table to disk, each time the number of writable blocks is specified by the initialization

); str_len-= len; str = str + len ;... if (data_len = OS _FILE_LOG_BLOCK_SIZE-LOG_BLOCK_TRL_SIZE) {/* write a block */... len + = LOG_BLOCK_HDR_SIZE + LOG_BLOCK_TRL_SIZE; log-> lsn = ut_dulint_add (log-> lsn, len );...} else/* Change lsn */log-> lsn = ut_dulint_add (log-> lsn, len );...} The LSN is not reduced. It is the unique identifier of the log location. There are lsn in the redo log write, checkpoint build, and PAGE header. About log writing: F

written and guaranteed to be rolled back, making it possible to roll back all modifications if the commit fails. The redo information here is actually the redo information of the rollback segment. Write-priority protocols guarantee the atomicity of transactions in the database transaction layer. 3.3 Transaction Submission When a transaction commits, a SCN is assigned and a redo log record containing that SCN submission is established. The commit process does not end when some redo records (i

MySQL Engine Features-InnoDB redo log roamingPreface InnoDB has two very important logs: undo log and redo log. The former is used to ensure the atomicity of transactions and the MVCC of InnoDB, and the latter is used to ensure transaction persistence. Like most relational databases, InnoDB records physical changes to data files and ensures that logs are always logged first, that is, the so-called WAL, before the persistent data files, ensure that the previous redo logs have been written to the

, in order to ensure transaction persistence even if the transaction fails. This is generally referred to as no-datablock-force-at-commit. 3.4 thread checkpoint event When a thread checkpoint event occurs, the dirty data protected by the redo record whose SCN is less than the specified value will be refreshed to the data file. After completion, the thread checkpoint