oex index

http://blog.itpub.net/22664653/viewspace-1210844/--This blog is written in a finer, later lookICP (index condition pushdown) is an optimization of MySQL's use of index (level two index) tuples and sieve fields to extract data records from a table in the Where condition in the index. The idea of ICP is that the storage

Clustered index is an index. The logical order of the key values in the index determines the physical order of the corresponding rows in the table. The clustered index determines the physical sequence of data in the table. The clustered index is similar to the phone book and

Create a table first Create table 'menu _ employee '( 'Id' int (11) not null AUTO_INCREMENT COMMENT 'auto-incrementing primary key, no practical significance ', 'Employee _ pid 'int (5) default null comment' parent node serial number, which is generally the Department serial number, but there are exceptions and no group employees ', 'Employee _ id' int (5) default null comment' employee number, Department number + employee number ', 'Employee _ name' varchar (100) DEFAULT ''' COMMENT 'employee n

Further discussion on who is in front of the two index columns in the composite index -- Practice, index -- Further discussion on who is in front of the two index columns in the composite index -- Practice: The last time I talked about this example in the elder's QQ group: c

[Oracle]-[Index]: check data before creating an index, or create an index before inserting data. Problem: 1. Create a new table structure and create an index, import millions or tens of millions of data into the table using insert. 2. Create a new table structure, use isnert to import millions or tens of millions of da

TTL index:The TTL collection enables MongoDB to set the expiration time for stored data, after a specified period of time, or at a specified point in time, the collection is automatically cleared by Mongod. This feature facilitates the storage of some data that only needs to be kept for a certain amount of time, such as event data generated by the machine, logs, session information, and so on.First create a collection ttlcol:The TTL index is created a

Tags: physical example field multiple background font row data MySQL pointer########### index ########### @see Http://mp.weixin.qq.com/s/4W4iVOZHdMglk0F_Ikao7A Clustered Indexes (clustered index): A clustered index determines the physical ordering of data on disk, and a table can have only one clustered index, typicall

When selecting a record to perform the delete operation today, the index failure problem occurs as follows:Processing failed! Error message: [sqlexception ORA-01502 index vhl_v6.pk_web_app_tgt_obj or partition of such index is in unusable state]After checking the cause on the internet, go to the database and check the result as follows:1 pk_web_app_tgt_obj normal

Basic SQL Server Index knowledge (2) ---- clustered index, non-clustered Index [From] http://blog.joycode.com/ghj/archive/2008/01/02/113291.aspx As I needed to train my colleagues on database indexing knowledge, I collected and sorted out this series of blogs. This is a summary of index knowledge. After summing up,

class index, parent class index, and interface index collectionThe above describes the class file, the magic number from the beginning, the minor version number, the major version number, the constant pool entry, the constant pool, the access flag. Then the next step is to determine the class index of the class's inh

Explanation of the usage of JsRender for index circular index, jsrender index This example describes the use of JsRender for index loop indexes. Share it with you for your reference. The specific analysis is as follows: JsRedner and JsViews (JsViews are further encapsulated based on JsRender) are called the next-genera

Label:MySQL Index implementation: B-tree,b is balance, which is commonly used for database indexing . Using the B-TREE structure can significantly reduce the intermediate process that is experienced when locating records, thus speeding up the access speed. While B+tree is a variant of b-tree, MySQL generally uses b+tree to implement its index structure. In general, the