mysql query cache size

. It is a neat feature that pads values that are (here it comes) less than the specifiedDisplay widthWith zeros, so that you will always receive a value of the specified length. This is for example useful for invoice ids. So, concluding:The size is neither bits nor bytes. It's just the display width, that is used when the field hasZEROFILLSpecified. If you see any more uses inSizeValue, please tell me. I am curious to know. 1 See this example:Mysql> c

set to small, an error is returned. Query_cache_limit: Maximum capacity of a single Query result set that can be cached. The default value is 1 MB. The Query result set that exceeds this parameter will not be cached. Query_cache_min_res_unit: sets the minimum memory size allocated for each Query

as a string directly based on a pre-set hash algorithm, and then go directly to the query cache to find out if it is already cached. That is, if it is already in the cache, the select request will return the data directly, omitting all subsequent steps (such as parsing of SQL statements, optimizer optimizations, and requesting data from the storage engine), whic

the Query Cache to check whether the data has been cached. That is to say, if the select request is already in the cache, the data will be directly returned, thus omitting all subsequent steps (such as SQL statement parsing, optimizer optimization and Data Request to the storage engine), greatly improving performance. Of course,

(not explicitly stating that the query cache is not allowed, or if you have explicitly declared that you need to use query cache), MySQL will hash the received SELECT statement as a string directly based on a pre-set hash algorithm, and then go directly to the

| Value |+-----------------------+-----------+| Handler_read_rnd_next | 165959471 |+-----------------------+-----------+1 row in set (0.00 sec) Handler_read_rnd_next/Com_select returns the table scan rate-in this example, It is 521: 1. If the value exceeds 4000, check read_buffer_size, for example, read_buffer_size = 4 M. If this number exceeds 8 Mb, you should discuss with the developer about tuning these queries! View database cache configura

The example in this paper describes how Laravel uses caching cache data to alleviate the pressure of database queries. Share to everyone for your reference, as follows: Yesterday want to make their own home page cache, to achieve similar to the effect of generating static page cache, in the group asked everyone how to do the

Turn on caching, set cache size, and implement the following: 1, modify the configuration file, Windows under the My.ini,linux is my.cnf; On the last append to the configuration file: The code is as follows Copy Code Query_cache_type = 1Query_cache_size = 600000 Need to restart MySQL in effect; Then adopt the second way;

disable the function.The use of QC requires multiple parameter mates, the most critical of which is the query_cache_size and Query_cache_type, which sets the memory size of the cache recordset, and the latter sets the use of QC in what scenario. In the past experience, the medium-sized website, query_cache_size set 256MB enough. Of course, you can also make adjustments by calculating the QC's hit ratio.qca

For large websites such as facebook and ebay, if Memcache is not used as the intermediate cache layer, data access cannot be avoided. For general websites, as long as they have independent servers, you can configure Memcache to speed up Website access and reduce database pressure. Here we will mainly discuss the process relationship between Memcache and MySQL database interaction, and understand the role of

Hibernate's first level cache and level two cache are caches of entities, and he does not cache normal attributes, and if you want to cache normal familiarity, consider using query caching.For the query

configuration method: 1. Set query_cache_size to a specific size. The specific size depends on the actual situation of the query, but it is best to set it to a multiple of 1024, with a reference value of 32 M. 2. Add a row: query_cache_type = 1 The query_cache_type parameter is used to control the cache type. Note tha

The optimization of MySQL is not in line, has done several optimizations, but is not very ideal, or waste resources too much. I have always found that my MySQL cache hit rate is very poor, in good times to reach the 60-70%, but run a long time, only 10-20%. Checked some data about the cached parameter records Mysql>

Tags: think percent get conversion API hard disk Run Index TunProblem descriptionAn online cluster, the Query DSL that executes is the same, but the parameters are different. Statistics show that 98% ~ 99% of the query corresponding speed is very fast, only 4 to 6ms, but there are about 1% of the query response time between 100ms ~ 200ms. Cluster hardware configu

any effect in real life. Now2 Zerofill comes into play. It is a neat feature this pads values that was (here it comes) less than the specified display width with zeros, So, you'll always receive a value of the specified length. Example useful for invoice IDs. So, concluding: The size is neither bits nor bytes. It's just the display width, that's used when the field hasZerofill specified. If you see any more uses in the

can use Query_cache_size to set the maximum memory space that can be used.Connection thread caching (thread cache):Connection thread is MySQL in order to improve the efficiency of creating connection threads, keep some idle connection threads in one buffer for new incoming connection requests, which can greatly improve the efficiency of creating a connection for applications that use short connections. Aft

application calls Transaction's commit () method , the method first flush and then commits the transaction to the database When an application performs some query (HQL, Criteria) operation, if the properties of persisted objects in the cache have changed, the cache is flush first to ensure that the query results refle

[Asp. Net] State management (Session, Application, Cache, Cookie, Viewstate, hidden domain, query string), cookieviewstate Running result: 2. Session is the user variable stored on the server. I can set a value for the Session on one page and access it on another page. The method for attaching a Session value is as follows: 2. Application Explanation: If data should be shared among multiple clients,

When you submit a query, MySQL will analyze it to see if some optimization can be done to make it faster to process the query. This section describes how the query optimizer works. If you want to know the optimization methods used by MySQL, you can refer to the

The optimization of mysql is not feasible. It has been optimized several times, but it is not ideal. It is still a waste of resources. I have always found that the cache hit rate of my mysql is very poor. When the condition is good, it reaches 60-70%, but the running time is long, only 10-20%. I checked some information about some cached parameter records.