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operation based on primary key. 4.2.2 InnoDB Optimization Essentials 1) Try to use Short,integer's primary key. 2) Press primary key order when Load/insert data. If the data is not sorted by primary key, then the database operation is sorted first. 3) The load data is for setting the set Unique_checks=0,set foreign_key_checks=0, which avoids the overhead of foreign key and uniqueness constraint checks. 4) Use prefix keys. Because InnoDB does not have a key compression function. 4.2.3 InnoDB ser

*********************************************** Declaration ********************************************* *original works, from the "Deep Blue Blog" blog, Welcome Reprint, please be sure to indicate the source when reproduced , otherwise be held responsible for copyright law. Please leave a message or email ([email protected]) to indicate the error.This reprint must be kept here: http://blog.csdn.net/huangyanlong/article/details/39216791Deep Blue Blog:http://blog.csdn.net/huangyanlong***********

the variable and the size of the memory buffer. The parameter can be set to 384M or 512M for a server that has around 4GB. By checking the status values key_read_requests and Key_reads, you can see if the key_buffer_size settings are reasonable. The proportional key_reads/key_read_requests should be as low as possible, at least 1:100,1:1000 better (the above status values can be obtained using the show status like ' key_read% '). Note: This parameter value setting is too large to cause the over

#每个线程将使用2MB (MySQL AB binary version is a KB) stack, in the worst-case scenario, Sort_buffer_size + record_buffer_size Additional memory is also used. Can be changed to 512M #innodb_buffer_pool_size = 16M #主要用来存储表结构和数据字典, the more tables require more memory, you can change to 16M#innodb_additional_mem_pool_size = 2M#日志组中的每个日志文件的大小(in megabytes). If n is the number of log files in the log group (Innodb_log_files_in_group), the ideal value is 1M to the buffer pool (innodb_log_buffer_s

consume 500*sort_buffer_size (8M) =4g memory# when Sort_buffer_size exceeds 2KB, memory allocations are made using mmap () rather than malloc (), resulting in reduced efficiency.# explain Select*from table where order limit; appears FilesortMax_length_for_sort_data= 1024# MySQL sort using sort_buffer_size and max_length_for_sort_data two ways, if the length and value of the query column and the order by column are greater than 1024, the Max_length_fo

.Max_connections = #MySQL允许最大的进程连接数, if too many connections error is frequently present, you need to increase this valueMax_connect_errors = 6000 #设置每个主机的连接请求异常中断的最大次数, when this number of times is exceeded, the MySQL server disables the host connection request,#直到mysql服务器重启或通过flush the hosts command to clear information about this hostMax_allowed_packet = 32M #限制接收数据包的大小, the insertion or update fails when a single data exceeds this value.#show VARIABLES like '%max_allowed_packet% '; View curr

UNCOMMITTED), read Committed ( Read-committed), REPEATABLE read (repeatable read), Serializable (serializable) tmp_table_size=32m## temp Table size key_buffer_size=32m## used to cache the index of the MyISAM storage engine (default 8M, if using the Innodb storage engine, this value is set to 64M or smaller) # # calculation formula: Key_reads/key_read_requests * -The value of% is less than0.1%# # INNODB storage Engine related parameters innodb_file_pe

set of memory once for the first time each connection (session) needs to use this Buffer.# sort_buffer_size is not the bigger the better, because it is a connection-level parameter, too large settings + high concurrency may drain the system memory resources. For example: 500 connections will consume 500*sort_buffer_size (8M) =4g memory# when Sort_buffer_size exceeds 2KB, memory allocations are made using mmap () rather than malloc (), resulting in re

but beware of setting memory usage too high in #innodb_buffer_pool_size= 16M the #innodb_additional_mem_pool_size= 2M the # Set: _log_file_size to% of buffer pool size About #innodb_log_file_size= 5M the #innodb_log_buffer_size= 8M the #innodb_flush_log_at_trx_commit= 1 the #innodb_lock_wait_timeout= + - [mysqldump] the QuickBayi Max_allowed_packet= 16M the the [MySQL] - No-auto-rehash - # Remove The next comment character if you is not a familiar

them. This operation has the SQL thread complete#Max Binlog keeps daysExpire_logs_days = 30#Binlog removed for more than 30 daysbinlog_cache_size= 1M#Session Level#ReplicationReplicate-wild-ignore-table =MySQL.%#Ignore database and table when copyingReplicate-wild-ignore-table = test.%#Ignore database and table when copying#Slave_skip_errors=allkey_buffer_size= 256M#MyISAM index buffer, only key does not have dataSort_buffer_size = 2M#sort buffer size; thread levelRead_buffer_size = 2M#buffer s

Modify PHP Upload file size, response time1. Modify PHP.ini1, post_max_size refers to the form post to PHP can receive the maximum value, including all the values in the form, the default is 8M (to 150M), see you need to change.2, first confirm file_uploads = on whether to allow the upload of files via HTTP switch, the default is on is open.Upload_tmp_dir upload the file cache directory via HTTP, check whether it can be written;Finding upload_max_file

option, such as Upload_tmp_dir = "D:/fileuploadtmp", The representative has a fileuploadtmp directory under the D-Disk directory, and reads and writes permissions to this directory. Upload_max_filesize = 2M The maximum size of the uploaded file. The default value of this option is 2M, that is, file upload size is 2M, if you want to upload a 50M file, you must set upload_max_filesize = 50M.However, only setting upload_max_filesize = 50M will not enable uploading of large files, and we must also

1. Open php.ini2. Find Post_max_sizeThe form submits the maximum value, which is not limited to the size of the individual file being uploaded, but to the entire form's submission data.The default is 8M, set to the value you need, this parameter is recommended to be set larger than upload_max_filesize3. Find File UploadsAllow switch to upload file via http, confirm file_uploads = On4. Find Upload_tmp_dirFile Upload to the server where temporary files

Method One:How to view the memory limits of Android to appsEach phone has a different limit on the app, and after all, we can use the following methods to see the maximum memory available to individual apps:Execute command:Shell Code ADB Shell Getprop | grep heap [Dalvik.vm.heapgrowthlimit]: [64m] [Dalvik.vm.heapsize]: [256m] [Dalvik.vm.heapstartsize]: [8m] After entering the command, we look back to the above results.[Dalvik