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Exploring the massive data insertion in mysql (qualitative change due to quantitative change) classification: See the Visio diagram Pay attention to the following points for importing large amounts of data: Batch import: after importing a batch and finally committing (commit), you can use jdbc (executeBatch) for batch processing, but pay attention to its maximum limit. Otherwise, only part of the SQL statements will be executed, SQL statements

Some methods for optimizing the query speed when mysql processes massive data bitsCN.com Recently, due to work needs, I began to pay attention to the optimization methods of select query statements for Mysql databases. In actual projects, it is found that when the data volume of the mysql table reaches the million level, the query efficiency of common SQL statements decreases linearly. if there are many query conditions in the where clause, the query

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. However, this word does not exist in another large database ORACLE. This is not a pity, although other methods (such as rownumber) can be used in ORACLE. We will use the TOP keyword in future discussions about "display stored procedures by page for tens of millions of data records.So far, we have discussed how to quickly query the data you need from a large database. Of course, the methods we introduced are all "soft" methods. In practice, we also need to consider various "hard" factors, such

The company's data center plans to migrate a massive amount of data and add a certain time field (originally datatime type, now added a date type). The data volume in a single table reaches more than 0.6 billion records, the data is based on the time (month). Due to the busy schedule, the summary has not been made, so I cannot remember the details. Here I will simply summarize the situation at that time and forget it. Chaos When a task is initially re

Mysql tutorial paging optimization code for massive dataPage indicates the page number.Pagesize indicates the number of entries displayed on each page.Conditon indicates some conditions view sourceprint? 1 select * from table where conditon order by id limit (page-1) * pagesize, pagesize;In this way, there was no problem with paging in the early stage, but when the data in the table reached 100 million, the problem gradually occurred. When searching h

-Fields with high key-value repetition rate -Specific types of data -It is not suitable for frequent DML table creation. 3. Full-text index -Full-text indexes are suitable for text storage in fields and are often used for text search. Iv. Summary For a massive database, no index is fatal, but the same is fatal if you choose the wrong index. Next we will compare the advantages and disadvantages of each index: 1. Full-text index: Advantage: indexes are

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order. 2. Try to avoid null value determination on the field in the where clause. Otherwise, the engine will discard the index and perform full table scanning, for example: Select id from t where num is null You can set the defaul

The official release of Fedora11 in June 2 will bring us richer new features and better user experience. As a radical pioneer in many new technologies, Fedora11 is worth looking forward! New features that have been adopted by the ora project steering committee will be added to the ora11 release. It allows two or more users to work independently on a computer using their own keyboard, display, and mouse. Without using Windows, you can compile and debug Windows programs from Fedora. The official

/m) kn. p = e-kn/m is to simplify the operation, here is used to calculate e when the approximate:So that the ρ is the ratio of 0 in the bit array, then the mathematical expectation of ρ is e (ρ) = p '. In the case where ρ is known, the error rate required (false positive rates) is:(1-ρ) is a scale of 1 in a bit array, and (1-ρ) k means that the K-times hash is just 1 of the range, which is false positive rate. The second approximation of the above is already mentioned in the previous step, and

to actually use space when this bitSet represents a bit value; An integer multiple of 64;New BitSet (950) does not mean to establish a 950-size BitSet, just that the initial size of the built BitSet can hold at least 950 bit, the size is always system control, and its size is a multiple of 64, even if BitSet (1), Its size is also 64Bitset can guarantee that "if the decision result is false, then the data must not exist, but if the result is true, then the data may or may not exist (conflict ove

PHP generates a massive two-level domain name problem If I want to www.abc.com/aa.php?id=aa to aa.abc.com such as how to achieve the master to consult with you ------Solution-------------------- PHP Code $str = ' Www.abc.com/aa.php?id=aa ';p reg_match (' #id = ([^]+) #is ', $str, $m); echo "{$m [1]}.abc.com";------Solution--------------------Domain name to do pan-resolution, *.abc.comURL to do the rewrite.------Solution--------------------Khan,

different, many efficient algorithms will be due to cost problems, space loss problems are directly pass. And, most of the switching technology is index positioning technology, not search technology, because the search algorithm relies on a lot of intermediate state, and on the hardware, it is difficult to maintain a stateful system or need a lot of space to maintain state information. We can understand the switching mechanism through CPU cache, and the exchange table can be seen as the cache o

+ "%y%m%d" 'Sql= "Use userbehavior;\nSelect Id,replace (replace (Path, ' \ n ', ' @ '), ' \ R ', ' @ '), replace (replace (Content, ' \ n ', ' @ '), ' \ R ', ' @ '), Createtime from $ Table into outfile '/data/backup/mysql_data/new_collection/' date-d yesterday + "%y-%m-%d" '. csv ' \ nFields TERMINATED by ' | ' LINES TERMINATED by ' \ n ' "/usr/bin/mysql-uroot--password= "Password"-D userbehavior-e "$sql";cd/data/backup/mysql_data/new_collection/Tar czvf ' date-d yesterday + "%y-%m-%d" '. tgz

In February, I wrote a method http://blog.csdn.net/great_domino/archive/2005/02/01/275839.aspx for SQL Server to optimize massive queries. Recently, some colleagues have encountered the problem that SQL Server has slow records of more than one million records. SP often encountered a large number of data statistics problem, which may be a coincidence. Find a simple method! I wrote an article The common practice for statistical records is: Select count

, and the summary of the total number of records needs to be implemented by using the coprocessor endpoint separately, which increases the computing workload; if it is placed on the client for paging, it is not feasible for massive data volumes. Of course, the corresponding index table can be generated for this table in Hbase. There are several secondary indexes and several tables. For example, the rowkey of the primary table is designed as rowkey = "

Problem: Find the 10 most visited IP addresses in the log file Similar Variants include: 1,Search for the 10 most popular search terms in the search engine record; 2,Search for 10 words with the highest frequency in a large file; 3. Web ProxyIn the record,Find the top 10 most visited URLs; 4,Sort the search records of a search engine by frequency; 5,Massive Data,Find the one with the highest frequency; These problems generally require that the data c

Recently, we are working with our team to Port Company A's X platform to Company B. We all know that, data transfer is inevitable for software migration projects-data can be copied from one place to another. However, Company B's old X platform has been on the market for 5 to 6 years. It is common to have millions of data records on a single table. If we only say that the data can be properly "placed" on the new platform, that's easy, but how long does it take to transfer

MySQL details (19) ---------- paging Query Optimization for massive data, mysql ---------- The detailed explanation of the paging, please see the http://blog.csdn.net/u011225629/article/details/46775947 View the code print 1 SELECT * FROM table order by id LIMIT, 10;The preceding SQL statement does not have any problems in principle or in practice. However, when the data volume of the table exceeds 100,000, the preceding statement is executed again, i

Optimization of SQL massive data query and non-use like processing solutions, data query like 1. To optimize the query, try to avoid full table scanning. First, consider creating an index on the columns involved in where and order.2. Try to avoid null value determination on the field in the where clause. Otherwise, the engine will discard the index and perform full table scanning, for example:Select id from t where num is nullYou can set the default v