checkpoint 13500

also temporarily written to the redo log_buffer, the file will be synchronized to the file only when a certain event is triggered. The size of the transaction log file is closely related to the overall IO performance of Innodb. Theoretically, the larger the log file, the less refresh actions required by the Buffer Pool, and the higher the performance. However, we cannot ignore another thing, that is, the recovery after the system Crash. Innodb records every modification made to the data and ind

exist in the buffer cache. This is clearly unreasonable. As you can see from here, this starting point actually shows that the dirty blocks in the buffer cache that correspond to the redo entries in the log file before this starting point have been written to the data file, so that there is no need to consider the recovery after the instance crash. And after this beginning of the redo items corresponding to the dirty block is not actually written to the data file, if in the recovery after the

Label:MySQL Engine Features · InnoDB Crash Recovery processIn the previous two monthly report, we introduced the knowledge of InnoDB redo log and undo log in detail, and this article will describe the main process of InnoDB in the case of crash recovery. This article code analysis is based on the MySQL 5.7.7-RC version, the function entry is innobase_start_or_create_for_mysql , this is a very verbose function, this article only involves and crash recovery related code. Before reading this articl

log file copy (a copy of the log file at the end of the dump), redo the completed transaction, and undo the unfinished transaction.The log files are scanned first to identify the committed and incomplete transactions at the time of the failure, and to record them into the redo queue and the undo queue, respectively.The log file is then scanned for redo processing of all transactions in the redo queue. Reverse-Scan the log file for undo processing of all transactions in the undo queue.Recovery o

When the Oracle kernel finds that an instance is dead and the corresponding thread opens the status bit in the control file, it will automatically restore the instance. When the Oracle kernel finds that an instance is dead and the corresponding thread opens the status bit in the control file, it will automatically restore the instance. Instance recovery is used to recover failed instances or failed instances in the parallel server environment, therefore, instance recovery can refer to both

When talking about the transaction log, you have to talk about the Checkpoint, or CKP for short. The transaction log and the Checkpoint both exist for the rapid recovery of the database. We need to know what the checkpoint is and what it has to do with the transaction log. What does CKP do? In general, data changes are not directly written to the mdfndf data file

the current requirements. You can set the maximum number of available instances to limit the amount of memory that SQL server uses to lock. The default value is 0, which allows the SQL Server to dynamically request the allocation and revocation of locks based on system requirements. SQL Server allows up to 40% of the memory to be locked. Keep the locks parameter as the default value 0 and allow SQL Server to allocate locks as needed. This option is an advanced option and can only be set with sp

Instance recovery is used to recover failed instances or failed instances in the parallel server environment, therefore, instance recovery can refer to both crash recovery and instance recovery in the parallel server environment (one or more failed instances can be recovered as long as one surviving instance ). The target of instance recovery is to restore the data blocks of failed instances in the data buffer and disable the running threads. Only online archiving logs and current online data fi

Tags: IMA crash memory logs ordered also data class CEOAs with Oracle, SQL Server also makes instance recovery (Instance Recovery) when non-conformance is turned off, and this article describes some of the SQL Server instance recovery knowledge based on the article in the stack overflow. Original link:https://stackoverflow.com/questions/41932735/sql-server-instance-recovery about Oracle's instance recovery reference before the blog post: http://www.cnblogs.com/leohahah/p/6973600.html First look

write SCN and commit scn to the data block header, the checkpoint also writes SCN to the control file and data file header, the user's DML and COMMIT only write SCN and commit scn to the data block header without updating the SCN of the control file and data file, the SMON rollback starts from the file header's SCN, that is, from the previous checkpoint. The SMON rollback is a data block not identified as

Introduction to backup implemented by perforce Creation Method: On the perforce server, use the-JC flag to create the server. By default, the P4d-r root-JC is saved as the checkpoint. N file and journal. n-1 in the root directory of the perforce program to record historical data at the same time. The last checkpint. N and this journal. This is all the information of the current checkpoint database. For ex

, out of the partial according to the following 7 level calculation.Serial numberIncome RangeRateCalculator Deduction Number1Over 0 to 15003%02More than $1500 to $450010%1053More than $4500 to $900020%5554More than $9,000 to $35,00025%10055More than $35,000 to $55,00030%27556More than $55,000 to $80,00035%55057More than 80,00045%13505For example: Wang a month total income 3600 yuan, personal income tax = (3600-3500) *3%=3 yuan;Another example: Lee a month income of

,department_id,job_id,salary from Employees 2 where job_id like ' sa_% ' and rownum 3/ 5 rows created. Hr@test1107> select * from EMP; employee_id last_name department_id job_id SALARY ----------- ------------------------- ------------- -------- ---------- 145 Russell Sa_man 14000 146 Partners Sa_man 13500 147 Errazuriz Sa_man 12000 148 Cambrault Sa_man 11000 149 Zlotkey Sa_man 10500 Hr@test1107> select * from Sales_staff_vu; employee_id last_nam

Oracle SCNSystem Chang Number) is an important mechanism in Oracle, it plays an important role in Data recovery, Data Guard, Streams replication, and related synchronization between RAC nodes. Understanding the operating mechanism of SCN can help you gain a deeper understanding of the above functions. Before understanding Oracle SCN, Let's first look at how data changes in Oracle transactions write data files: 1. Start the transaction; 2. Find the required data block in the buffer cache. If no d

Brief introductionThe recent test server for data archiving, during which the programmer found a problem, lack of space, I look for reasons to find the log file explosion. The database is then changed to a simple recovery model, but this problem still exists. After querying the data, it was found that the log file still increased in simple mode.Simple conceptSimple recovery mode is also called "Checkpoint with Truncate log", in fact, the name is more

Issue Log Problem Universal article Author: Aladdin Published time: 2002/12/06 03:57pm The following information originates from sybase.com.cn Ssybase every database in SQL Server, whether it is a system database (Master,model, Sybsystemprocs, tempdb), or a user database, has its own transaction log, each with a syslogs table. Log records the user's modifications to the database, so if the command is not cleared, the log will grow up to fill up the space. Clear Log Available DUMP TRANSACTION com

the SQL statement, which means that LGWR writes the SQL statement Redolog from log buffer to the redo log file, and redolog the successful write means that the SQL statement was successfully committed. As to whether the buffer that has been modified by this SQL statement has been written back to the data file, there is no necessary connection with whether the SQL statement is committed. So when does dirty buffer write back to the data file? During checkpoin