by modifying the data dictionary, rather than deleting the data. Truncate reduces HWM, releases extent, and regenerate data_object_id. It is faster than delete because it does not need to delete data at all. redo only records the operation itself and does not have redo records with a large amount of data. Therefore, for the truncate operation, if we know the previous data_object_id and the space is not reused, we can still retrieve the data.
Under what circumstances will select generate redo?
background logic code separation of ideas, disadvantages: efficiency than the first kind of low + third: MVC design, has been used, the advantages: is to force the user input, logic, output phase separation, maintenance cost reduction, but the implementation of low Efficiency. - the thinkphp Framework Introduction *Born in 06, the original name of Fsc,07 was renamed As: thinkphp, a Chinese development framework, the Chinese learning cycle will be r
1.Thinkphp Family was first born in 2006 early, originally named fsc,2007 Year new year's Day renamed thinkphp, Self-developed framework with Chinese documentation and community2.Tinkphp Download: http://www.thinkphp.cn the latest Version of 5.0, currently used more is 3.2.3 version3. File directory:4. DeploymentFirst step: Create a Site DirectoryStep Two: Modify the configuration fileStep three: restart ApacheFourth: Modify the hosts file to bind th
information for printing the "ext2/ext3" file systemDUMPE2FS [-BFHIXV] [-O superblock=superblock] [-O blocksize=blocksize] Device-H: View Super Block information (grouping information), partition with group managementFile system detection and RepairOften occurs after the crash or abnormal shutdownMount for file system labeled "Dirty"Fsck:file System CheckFsck-t Fs_typeFsck. Fs_type[Email protected] ~]# fsck.fsck.btrfs fsck.ext2 fsck.ext4 fsck.minix fsck.vfat Fsck.cramfs fsck.ext3
File System Detection:File system Detection Tool fsck is required because the hardware or software may also cause the computer to crash or suddenly shut down due to a power supply, which results in a file system error. fsck Command Check and repair a Linux filesystemDetecting and repairing Linux file systemsGrammar:fsck [-LRSAVRTMNP] [-C [FD]] [-t fstype] [filesystem ...] [--] [Fs-specific-options]Fsck.type command:View the file systems supported by fsck[Email protected] test]# fsck[tab][tab]fsc
root filesystem small and compact (which is the correct approach). -R When using-A flag to check all file systems, skip the root filesystem (it may have been mounted as read/write). -T displays the title at startup. -V produces redundant output that contains all commands for the specific file system being executed. FS-specific-Options Fsck does not understand an option that is passed to a particular file system inspector. These options must be--The boot options and parameters will be passed to
where to download the third party screenshot tool?
Picpick
1, Picpick
Picpick has a full screen, active window, designated areas, fixed areas, hand-painted area functions, support scrolling screen, screen color, support dual display, with whiteboard, screen ruler, rectangular coordinates or polar coordinates display and measurement, with powerful image editing and annotation function.
Download Address: Picpick
2, Snipaste
Snipaste
Snipaste is a simple but powerful
package--> Resolve Dependencies CompleteError: Package: libbluray1-0.4.0-6.el7.x86_64 (@atrpms)Required:/usr/sbin/ldconfigDeleting: glibc-2.17-55.el7_0.1.x86_64 (@updates)Not foundUpdate, by: glibc-2.17-55.el7_0.3.x86_64 (Updates)Not foundYou can try to add the--skip-broken option to resolve the problemYou can try to execute: Rpm-va--nofiles--nodigestWill resemble the one shown above, just a few one or two packages, try uninstalling it to see
[ROOT@FSC
exchange the data stream as long as it sees the wavelength, time slot or the comparison of the band. Optical fiber is the most obvious and basic switching unit in optical communication networks. Wavelength and optical bands are also a very common switching unit. There is, of course, a time slot switching unit that continues to be the mainstream of optical network hosting services so far.
In the optical communication network, the GMPLS is extended to the MPLS tag, so that the label can be labe
time will detect 1 open ITL, check the rollback segment header of the Transaction table discovery status is active, you need to construct 1 CR blocks;Clones the current block, undoing its most recent operation by rolling back the segment header and the rollback block;Buffer status can be viewed via x$bh.state0 Free No valid block image1 Xcur A current mode block, exclusive to this instance2 Scur A current mode block, shared with other instances3 CR A consistent read (stale) block image4 Read bu
Environment is AIX 6.1,db2 version 9.7.0.7First, see if the DB2 master process existsPs-ef|grep Db2sysIf there is no useDb2startOpen the database backup media as a cold standby data source, CD to the directory where the media is located:Cd/home/db2inst1/backupUse the redirect parameter to change the directory:1.>DB2 restore DB XXX from. Replace existing redirect without rolling forwardSQL1277W A redirected restore operation is being performed. Table space configuration can now is viewed and tabl
establishment of a tag exchange channel between all endpoints and the establishment of a request based on requirements. Data Streams of various data types on a link are rarely active, and a service only appears between several nodes, that is, the service is local, you can use this locality to establish a tag exchange channel based on requests to improve network scalability. GMLS establishes a tag exchange channel based on the request.These different label switching channels benefit from the typ
, separate surrounds (default)
3stack3-stack, shared surrounds
Laptop2-channel only (FSC V2060, Samsung M50)
Laptop-eapd2-channel with EAPD (ASUS A4.7)
Laptop-automute 2-channel with EAPD and HP-automute (Lenovo N100)
Ultra2-channel with EAPD (Samsung Ultra tablet PC)
Samsung2-channel with EAPD (Samsung R65)
Samsung-p502-channel with HP-automute (Samsung P50)
There are a lot of models below. Try to select the model corresponding to your model. If it d
regarded as a virtual representation of the physical structure. Therefore, the label switching channel indicating the low-level synchronous optical network circuit (SONET) must be nested into the high-level synchronous optical network circuit 。
Similarly, a tag exchange channel running between optical switching cable interfaces (FSC) may contain a tag exchange channel running between switching function interfaces (LSC, the tag exchange channel runnin
In fact, if you have studied C language, use stdio.h directly.The middle function is the simplest, that is, the use of fopen ("Xxxx.xxx", "RB"); and then call Fread/fwrite; Call Fclose when you close it.If you use CreateFile in the Windows Native API, you do not need to differentiate what binary is not binary, as long as the return value of this function is not invalid_handle_value, you can continue to use Readfile/writefile To read and write, and then use CloseHandle to close. This is directly
cannot find the corresponding block in the DB buffer immediately. The former is over 10% and is not recorded in the list, the latter has been written to the disk. If you read the database buffer again and modify the buffer, too much IO will affect the performance.
What is the relationship between snapshot and old snapshot?
Premise: This block has been used for other sessions (clean), or the block is being occupied (dirty ), ITL (itl, xid, flag, uda, scn \ f
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