Time when a checkpoint appears (1) explicitly execute the checkpoint statement. Check points appear in the current database for connection (2) Minimum log record operations are performed in the database, for example, large-capacity replication is performed in a database using the large-capacity log recovery mode (3) you have used ALTERDATABASE to add or delete database files (4) Restart S
Time when a
Assume that the database has two log groups: log1 and log2. First, --> log1 --> log2 --> log1. At this time (log2 switches to log1), the checkpoint will be flush dirty block to datafile, this triggers dbwn to write dirty buffer. log1 can be used only after all dirty blocks covered by log1 are written to datafile. If dbwn writing is too slow, lgwr must wait for dbwn to complete, then "Checkpoint not complete
:
Pass # Moves the file reading pointer fd to the content corresponding to the checkpoint
# Check The rule for point is to read a file on one or more lines, and then send this line or lines into the
# Check file check_point. Run the program again at a later time to continue running from that checkpoint.
def gocheckpoint (fd,check_point):
if not Os.path.isfile (check_point):
f_check = open
Check Point
Checkpoint Mode
Vision Wang)
2009-02-13 Category
Information Security Behavior Model Motivation, problems, and Influencing Factors
I don't know if you are the same as me.
Due to strict personnel access control, if I don't show my work permit and punch in, I won't be able to enter the office area. Taking the entrance as an example, the process is as follows:
Figure 03-01: entry process
From the above process, the above "gua
Verification checkpoint SCN during Oracle Database startup
SCN (System Change Number) is an important mechanism for Oracle databases. SCN is used when the database is started, read consistency, data recovery, and FLASHBACK operations.
1. the SCN number is an important time mechanism and can be converted between the two.
1). Convert the time to the SCN Number:SQL> select timestamp_to_scn (sysdate) from dual;
TIMESTAMP_TO_SCN (SYSDATE)------------------
Tags: style http color io os ar strong SP dataBased on performance considerations, the database engine performs changes to the database data pages (pages) in memory (buffer cache) and does not write the modified page back to disk after each modification. More accurately, the database engine periodically generates a checkpoint on each database. Checkpoint will write the current in-memory modified pages (dirt
The following WLAN test is successful in ubuntu11.04:
Install L2TP IPSec VPN
We will use l2tp-ipsec-vpn software for Werner Jaeger
First, open the terminal and execute the following command to install the l2tp-ipsec-vpn Software
Sudo apt-add-repository PPA: Werner-Jaeger/PPA-Werner-vpnsudo apt-Get updatesudo apt-Get install l2tp-ipsec-
What exactly isCheckpoint ?1,Sparkin the production environment, we often facetranformationsof theRDDvery much (such as aJobincluded in1million ofRDD) or specifictranformationproduced byRDDThe calculations themselves are particularly complex and time-consuming (for example, calculations often exceed1hours), we must consider the persistence of the calculated results data;2, Spark is good at multi-step iterations, and is good at Job -based reuse, which can greatly improve efficiency if the data ge
the Hyper-V server, open the Hyper-V management Console, right-click the virtual machine where you want to create the snapshot, select Checkpoint650) this.width=650; "height=" 260 "title=" image "style=" margin:0px;border:0px;padding-top:0px;padding-right:0px; Padding-left:0px;background-image:none; "alt=" image "src=" http://s3.51cto.com/wyfs02/M01/54/74/ Wkiol1sdbyfg0nvtaadbwpsp06c375.jpg "border=" 0 "/>2. After performing a checkpoint, the system
When developing the discuz logon script, a problem occurs: How to verify the real logon success of a virtual user? Of course, people familiar with the LoadRunner tool will know that checkpoints are used in the script, yes, that's right!
We know that there are two LR checkpoint functions: Text checkpoint web_find (), web_reg_find (), and image checkpoint web_image
What is a VPN?
The English full name of the VPN is "virtual private network", translation comes from "The fictitious specialized network". As the name suggests, virtual private network we can understand him as a virtual out of the enterprise internal line.
This VPN's English full name is "Virtual private network", translates is "The fictitious private network". As the name suggests, the virtual privat
What is VPN?
The full name of VPN is "Virtual Private Network", which is translated as "Virtual Private Network ". VPN is defined as a temporary and secure connection through a public network (usually the internet). It is a secure and stable tunnel through a chaotic public network. Using this tunnel can encrypt data several times to ensure secure Internet use.
Pptp settings and local vpn (and solve the problem that ssh cannot access the remote host under the vpn)1. Install pptpSudo apt-get install-y ppp pptpdsudo vim/etc/pptpd. conf modification: option/etc/ppp/pptpd-optionslocalip 172.31.26.19 (local vpn address) remoteip 172.31.26.20-200 (vpn customer point address range)C
The CKPT type of the Oracle checkpoint is used to write the checkpoint to the control file and data file header. Check points are of the following types: Thread checkpoints is the database check point, which may occur in the following cases: closing the database consistently; alter systerm checkpoint statement; switching online redo log file; alter database begin
Compile a Python script to configure VPN in batches and a python script vpn tutorial
Origin
As we all know, the recent network is not harmonious, the speed is slow, and the VPN is still disconnected. Fortunately, yunti provides a lot of servers for switching, but there are quite a lot of yunti servers, in Linux, Network Manager does not support batch configuratio
The buffer cache memory of the CKPT checkpoint queue contains the chain and bufferLRU to concatenate available blocks (based on the Access Frequency). LRUW concatenates dirty blocks (Access Frequency) and cold-end blocks are first written to the hard disk. When CBC reads data blocks into the memory, it uses CKPT (chain): 1. It links dirty blocks. 2. It links the first dirty time (from small to large) the address of the RBA redo block address log block
It is estimated that the Checkpoint Lag calculation method of the rep process on the Oracle GoldenGate (OGG) destination end is called oraclelag.
This article is original. For more information, see the source.
It is estimated that the Checkpoint Lag calculation method of the rep process on the target end of Oracle GoldenGate (OGG) OGG
Background: The following shows the rep process at the OGG target end. A
Tags: dirty data condition default stat target PNG FAs answer technologyThis paper mainly summarizes the mechanism of writing dirty blocks in database.When a process is going to make changes to the data block1. Get CBC Latch2. Modify the buffer pin status3. Release CBC Latch4. Generate Redo Records5. Modify Buffer data block6. Move the dirty block to the checkpoint queue, so that the modification is complete.7. Get CBC Latch8. Modify the buffer pin st
Tags: TAC Delete read requires strong res PID start informationToday interview was asked a question, how to debug multi-process program, I answered GDB attach [PID], and then asked if some of the program data read wrong, but this phenomenon is accidental, this time to how to operate, then was ignorant ..., by looking up the data to find the answer, Now write down the blog post. Checkpoint Sometimes the occurrence of a bug occurs accidentally, if the
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