sonos indexing

blog, the order should be So, "published" Before the release, give it a "shelf reference", of course, this reference is the category of blog directory, tags (tags). Category directory is the scope of the article, tags (tags) is refined after the content of the keyword, is the title of the supplement, help memory. Therefore, tags (tags) is an index tag. Movies (DVDs), songs (CDs) themselves with attributes (such as publishing company, director, actor, singer, song name, etc.) is enough to iden

evaluated and stored in memory through random index access. Use the show index from command to view the index cardinality (cardinality) See more highlights of this column: http://www.bianceng.cnhttp://www.bianceng.cn/database/MySQL/ InnoDB will be the first to open the table, or to execute analyze table, or the table size changes more than 1/16 or Show table status, or show index time will calculate the statistical information, if the server has a large number of data, this is a serious pr

I. My original procedure. In fact, my original program is quite simple, completely modified from the demo inside the Searchfiles and indexfiles. The only difference is that it refers to the SMARTCN word breaker. I post the code that modifies that point. Indexhchinese.java: Date　start　=　new　Date(); try　{ 　　 IndexWriter　writer　=　new　IndexWriter(FSDirectory.open(INDEX_DIR),　 　　　　　　　　　　 new　SmartChineseAnalyzer(Version.LUCENE_CURRENT),　true,　IndexWriter.MaxFieldLength.LIMITED); 　　 indexDocs(writ

-Sort_buffer_size =2M theQuery_cache_size =64M *Table_open_cache =10000 $Thread_cache_size = thePanax NotoginsengMax_heap_table_size =64M -Tmp_table_size =64M theThread_stack =192K +Thread_concurrency = - ALocal-infile =0 theskip-show-Database +skip-name-Resolve -skip-external-Locking $Connect_timeout = - $Interactive_timeout = - -Wait_timeout = - -#***MyISAM theKey_buffer_size =512M -Bulk_insert_buffer_size =64MWuyiMyisam_sort_buffer_size =64M theMyisam_max_sort_file_size =1G -Myisam_repair_th

contains the column" See the 3rd chapter below. B + Tree This feature (all data addresses have leaf nodes) is also conducive to between value1 and value2 interval query, just find value1 and value2 (in the leaf node), and then the middle string up is the result. The SQL Server index structure is more like a B + tree, eventually a hybrid version of the B. + + tree, the data structure is human, not necessarily a pure B-tree or a simple + + tree. 3. Index contains column and bookmark lookup When i

Tags: type brackets unique order Chinese word breaker query files multiple columnsImprove query speed, facilitate sorting and grouping. (The process of sorting and grouping, if not indexed, results in temporary tables and filesort)Based on business logic, analyze the frequency and order of column queries, and build indexes and composite indexes.Primary key index (primary key),----> No index name is required because there is only one primary key indexUnique index (single key)---->unique Key Email

association4. Advantage---When char is very long, the enum remains an integer fixed length, when the amount of data queried is larger. The more obvious the advantages of enum.Indexes increase the speed of queries, increase the speed of sorting, and increase the speed of grouping Clustered and non-clustered indexes Clustered index: BtreeInnoDB engine, index and data are in one piece,InnoDB stores row data directly in the tree of the primary key index (both the primary key value and

performing many separate inserts. The downside is that you can't return an auto-incrementing ID, and when the system crashes, MySQL hasn't had time to insert the data, and that data will be lost.Force Connection Order Straight_joinCopy CodeThe code is as follows: SELECT TABLE1. FIELD1, TABLE2. FIELD2 from TABLE1 straight_join TABLE2 WHERE ...The SQL statement above shows that by Straight_join forcing MySQL to join the table in TABLE1, TABLE2 order. You can determine the connection order by Stra

can finally draw a panorama picture. Since the B + Tree of the secondary index has a similar structure to the primary key index, only the structure of the primary key index tree is drawn, including the green and yellow parts of the primary key non-leaf node and the primary key leaf node. Restore it to the more concise tree below, which is part of the B + tree. Note that there is no one by one relationship between page and B + tree nodes, page is just a save container for a record, it exists to

';~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Turn on SQL auto-trackingSET Autot[race] {OFF | On | Trace[only]} [Exp[lain]] [stat[istics]SET Autot onSET Autot TRACESET Autot TRACE EXPSET Autot TRACE STATTurn off SQL auto-trackingSET Autot OFFSelect/*+index (Dept pk_dept) */* from scott.dept;Select distinct file#,block# from V$BH where objd=dba_objects.data_object_id;Select object_name,data_object_id from Dba_objects where object_name in (' DEPT ', ' pk_dept ');Sel

actively stop the cursor movement (10) put the calculation into the business layer, not the database layer, in addition to the data-saving CPU, there are unexpected query cache optimization effect SELECT * from order where date This is not a good SQL practice and should be optimized for: $curDate = Date (' y-m-d '); $res = mysql_query ( ' SELECT * from order where date Reason: Freed the CPU of the database Multiple invocations, the same SQL passed in, can take advantage of q

works again. 2. When you make a like query on an indexed field. For example: SELECT * from Softwaredetailinfo where softuseline like '%oqc% '. However, some examples on the internet say that the like ' xx% ' index works. I haven't tried. 3. Determine if the index column is not equal to a value. '! = ' operator. Example: SELECT * from Softwaredetailinfo where softuseline! = 0 4. Perform an operation on the indexed column. The operations here include +-*/and other operations. Also includes the

To view the execution status:Select the code to press F5 directly, or click Tools===>>explain PlanI. Considerations for indexing:Indexes are useful when any single query retrieves less than or equal to 10% of the total number of rows in the table. This means that the candidate column for the index should be a column that stores a large range of values.A good index candidate is a column that contains only a single number for each record; The poor index candidates are those columns that contain on

Label:Indexes can still be used to improve efficiency when the selectivity of the index is low, but the value distribution of the data varies widely.A, the data distribution is not uniform in the special case, the selective index is also to be created.The amount of data in table serviceinfo is large, assuming there are 1 million rows, one of which has a field disposalcourseflag, and the value range is the enumeration value: [0,1,2,3,4,5,6,7].According to the rules established by the previous ind

I. Type of indexB-Tree indexes: Most of them are, so the characteristics of B-trees limit how indexes are used; you must look at the correct usage limits for indexes (with the limitations of composite indexes)http://blog.csdn.net/lovemdx/article/details/17683647Hash index: only memory engine supportCorrect use of index of B-Tree Select D from table where A = "x" and b= "Y" and C = "Z": Index is available for A B C at this time Select D from table where A = "x" and B >= "Y" and C = "

operation, so the database can not use the indexed data to avoid any sort operations3. The table scan cannot be avoided at any time:Because the hash index compares the hash value after the hash operation, even if the number of records that satisfy a certain hash key value is obtained, the query can not be completed directly from the hash index, or the actual data in the table is accessed, and the corresponding results are obtained.4. The retrieval efficiency is high, the index retrieval can be

is 1MB, then the database is partitioned into n=1024/8=128; if there are 256 records then each database has r=256/128=2 records.If there is no index, we need to traverse all data blocks. Searching by ID, we need 128 times to find a name we need. That is, n times .If the "ID" is indexed, that is, from small to large, we can use a binary tree to find the form. Then we only need 8 times, namely log2 256 = 8 times. That's log2n .As shownSo the essential difference between indexes is that they look

{ "ok" : 0.0, "errmsg" : "WiredTigerIndex::insert: key too large to index, failing 1483 { : \"Shandong partition | Shandong partition manufacturers | Shandong partition price | Shandong activity partition | Shandong hotel activity partition | Yantai activity glass partition | Shandong activity board |Shandong separated??...\" }", "code" : 17280 } MongoDB would not create an index on a collection if the index entry for an existing document exceeds the index key limit ( 1024x768 b

Tags: style blog using SP strong on Log BSThe first thing to look at is whether your Oracle optimizer is using RBO or CBO,(1) If Rbo is used, it will be carried out in the order of the rules.(2) If you are using a CBO, you can modify it using the Hint method.Syntax:SELECT/*+ Index (table indexname) */If the table in the query statement uses an alias, the table in the top statement must be an alias, otherwise it does not go to enforce the index.Example:Select/*+index (t idx_date) */from student

Label:Generally we like to use the database Manager UI to make changes to the data table structure, and then naturally place the "save" button to save, but when the amount of data is relatively large, the use of this trick will often appear "Cannot create INDEX" IX_ index name. The timeout period has expired.The time-out elapses before the operation completes or the server is not responding. "This error. At a loss, Waxman Zhang's article http://www.cnblogs.com/waxdoll/archive/2006/03/24/357972.h