Depends on the size of the stored segment. According to how to stop defragmenting and start living: the definitive of Bhaskar himatsingkaWord on fragmentation, which is recommended1) segments smaller than 160 m shocould be placed in 160 K extent tablespaces. = "uniform size 160 K2) segments between 160 m and 5120 M shoshould be placed in 5120 K extent tablespaces. ==> uniform size 5 m3) segments larger than
data, I guess it is a problem with group_concat. So I reduced the data in the temporary table by half and found that it was successful. So I guess group_concat has a length limit, google, sure enough.
For the group_concat function:
Group_concat is okay when the data volume is small, but there is a problem when the data volume hits
Group_concat: the default connectable length is 1024. If the maximum length has been set, it will be truncated to this length;
When group_concat is used in a select s
not understand it does not matter, we first to partition.
The above picture can be seen, the hard disk original partition, we put/dev/hda selected, and then click on the menu above delete the entire deletion.
Then we click on the menu new, start partitioning, first one/, file system selection Ext3, partition size is 1G, that is 1024M.
Mount point is mount points, input/
File system type filesystem, select Ext3 in dropdown
Size partition sizes, in MB, enter 1024
Press OK when finished
Wit
orgseq into V_orgseq from base_org_info WHERE ORGID = (select Parentorgid from base_org _info WHERE ORGID = v_orgid);Variant two: Querying all fields of a specified tableConditions of Use: applies only to the 3rd way of declaring a variable--Assigns the Virtual_card table data of id=5120 to the variable V_row_virtual_cardselect * into V_row_virtual_card from Virtual_card T where t.id = 5120;Descripti
# total number of cores = number of physical CPUs X number of cores per physical CPU# Total Logical CPUs = number of physical CPUs x number of cores per physical CPU X number of hyper-threads# View the number of physical CPUscat/proc/cpuinfo| grep "Physical ID" | Sort| uniq| Wc-l# See the number of cores in each physical CPU (that is, the number of nuclei)cat/proc/cpuinfo| grep "CPU Cores" | Uniq# View the number of logical CPUscat/proc/cpuinfo| grep "Processor" | Wc-l#查看CPU信息 (model)Cat/proc/cp
Small knitting personally think the best CPU should be the Intel Xeon e7-8870.
The key parameters for the Intel Xeon e7-8870 are as follows:
Number of cores: 10
Number of Threads: 20
Bus frequency: 6400
L3 Cache: 30MB
Production process: 32 NM
Working power: 130W
CPU Architecture: 64-bit
Instruction set: sse4.1,4.2
Virtualization Technology: Intel VT
The basic parameters of the Intel
processor executes the current instruction, which always causes an explicit bus lock to appear (2) in Pentium4, Inter Xeon, and P6 series processors, the lock operation is handled by either a cache lock or a bus lock. If memory access is cached and affects only a single cache row, the cache lock is invoked in the operation, and the actual area in the system bus and system memory is not locked. At the same time, other Pentium4, Intel
recovery benchmark.
SQL Server has a series of stunning records on the Microsoft Windows Nt®server platform that delivers the industry's best performance and best price/cost. When it was released in November 1998, SQL
Server 7.0 creates new records for Baan, PeopleSoft, tpc-c single node performance, and backup and recovery benchmark tests on the Windows NT server platform.
Two. Independent software vendors (isv,independent Software vendor) Benchmark
Hundreds of independent software vendors
Today, the reporter recommended a Lenovo R510G6 server, which is a 1U rack server that is small and lightweight and suitable for small and medium-sized enterprises who do not have much office space. The latest price is 25500 yuan. Lenovo full R510G6S50501G73N soft guide this server uses a 64-bit dual-core Intel Xeon TM50503.0GHz processor, supports a maximum of 2,
Today, the reporter recommended a Lenovo R510 G6 server, which is a 1U rack server that
, the computer has added an x87 chip to improve the floating point data processing capability. Later, the x86 Instruction Set and the x87 instruction set will be collectively referred to as the x86 instruction set. Although with the continuous development of CPU technology, Intel has successively developed the new i80386 and i80213to the past PII Xeon, piII Xeon, Pentium3. the Pentium 4 series and
1. view the production system version# Uname-
Linux applications-test-game 2.6.9-11. elsmp #1 SMP Fri May 20 18:26:27 EDT 2005 i686 i68
6 i386 GNU/Linux
# Cat/proc/version
Linux version 2.6.9-11. elsmp (bhcompile@decompose.build.redhat.com) (GCC version
3.4.3 20050227 (Red Hat 3.4.3-22) #1 SMP Fri May 20 18:26:27 EDT 2005
# Cat/etc/issue
Red Hat Enterprise Linux as Release 4 (nahant update 1)
Kernel R on an M
# Cat/etc/RedHat-release
Red Hat Enterprise Linux as Release 4 (nahant upd
I. server environment and Topology Planning1.1. Hardware server information and allocation
Server Type
Computer Name
IPAddress
Hardware configuration
Virtual Machine
Excas1
192.128.20.11
CPU Intel (r) Xeon l5520 2.27 GHz Memory 4 GB
Virtual Machine
Excas2
192.128.20.12
CPU Intel (r) Xeon l5520 2.27 GHz Memory 4 GB
Lspci-list all PCI devices
Popularization of pci:
PCI (Peripheral Component Interconnect) is a bus standard that connects the motherboard of an electronic computer and external devices.
Common PCI cards include NICs, sound cards, modem, TV cards, and disk controllers, as well as USB and serial ports. The original video card is usually a PCI device, but soon its bandwidth is insufficient to support the performance of the video card. PCI graphics cards are currently only used when an additional ex
example that the 1 GHz itanium chip can behave almost as fast as the 2.66 GHz Xeon/opteron chip, or 1.5 GHz itanium 2 is about as fast as 4 GHz Xeon/opteron. The computing speed of the CPU depends on the performance indicators of the CPU pipeline.
Of course, the clock speed is related to the actual computing speed. It can only be said that the clock speed is only one aspect of the CPU performance, not the
each logical core ran only 1 CPU threads, if hyper-threading is turned on, then the number of CPU threads = Number of physical CPUs * Number of logical cores per physical CPU *N, because each logical core ran 2 CPU threads. So, above the 24=2*6*2, you can judge that Hyper-threading is currently turned on.
1 2 3
[email protected] ~]# Cat/proc/cpuinfo | grep "model name" | Uniq Model Name:intel (R) Xeon (r) CPU X5670 @ 2.93GHz [ema
The recent release of the IntelXeon5500 series processor Nehalem-EP began to calm down. During this release, RedHat became the most attractive partner. Intel called the series of processors "the most revolutionary server processor since the launch of the IntelPentiumPro processor 15 years ago ". This statement proves to be among the numerous new performance records created during the release activities. During the release, RedHat and our partners are testing eight different industry standards.
T
profile- n Specifies the total number of threads- d background service --help Help7.sersync plug-in (plug-in Settings), plugin is set to True when it takes effect, name is called Plug-in, currently supports command REFRESHCDN socket HTTP four plug-ins, http plugin removedsersync压力测试[Email protected] ~]# Dmidecode | grep "Product Name" PRODUCTNAME:IBM System x3650 m4:-[7915k3g]-productname:00mv214[[email protected] ~]# grep name/proc/ Cpuinfomodel Name:intel (R)
solved. However, SSD disks are best at random reading. This hardware solves this problem naturally.
Therefore, leveldb is out-of-the-box with SSD disk raid.
For the leveldb standard version compilation, see here. Because the standard version uses the C ++ 0x feature, it is not supported on the RHEL platform, so for portability, for Basho, see the Standard C ++ version of port here. For details, see the directory c_src/leveldb.
This version is used for our tests. We tested the performance of lev
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