sonos indexing

has a significant impact on performance. In general, you can follow some of the following guidelines:(1) Smaller data types are generally better: smaller data types typically require less space in disk, memory, and CPU caches, and are processed faster.(2) Simple data types are better: integer data is less expensive to handle than characters, because string comparisons are more complex. In MySQL, you should use a built-in date and time data type instead of a string to store the time, and an inte

This article introduces the basics of MySQL Full-text indexing from the following aspects: Several considerations for MySQL Full-text indexing Syntax for Full-text indexing Introduction to several search types Examples of several search types Several considerations for Full-text indexing Sea

How do I build the best index? 1. To create an index explicitly CREATE INDEX index_name on table_name (field_name) tablespace tablespace_name pctfree 5 Initrans 2 Maxtrans 255 Storage ( minextents 1 maxextents 16382 pctincrease 0 ); 2. Create a function based index Commonly used with upper, LOWER, To_char (date) and other functions of the classification, example: CREATE INDEX Idx_func on EMP (UPPER (ename)) tablespace tablespace_name; 3. Create Bitmap In

This article simply narrates the application instance of the Full-text index, the MySQL demo version 5.5.24.Q: What are the applications for Full-text indexing?A: Full-text indexing is the key technology to achieve large data search at present.For more detailed introduction please own Baidu, this article no longer elaborated.-------------------------------------------------------------------------------- On

where sydw_bh= ' 5401 ' (indexing of SYDW_BH does not result in performance optimizations) Tables that are frequently inserted, deleted, modified For some business tables that are frequently processed, you should minimize the indexes, such as Zl_yhbm,gc_dfss,gc_dfys,gc_fpdy, as the query allows. Table fields with repeated data and distributed averages If a table has 100,000 rows of records, a field A has only T and F two values, and the probability o

Tags: Oracle--oracle Full-text indexing with Case study tuningFull-Text Search (Oracle text)Oracle text enables oracle9i to have powerful text retrieval capabilities and intelligent text management capabilities, Oracle text is a new name used by Oracle9i, known in oracle8/8i as Oracle intermedia text, Oracle8 was previously Oracle context cartridge. The indexing and lookup capabilities of Oracle Text are no

MySQL has not provided such complex functions as function indexing since ancient times. So how can this function be implemented in MySQL? Let's take a look at the concept of function indexing. Function indexes, also known as Expression indexes, are indexes created based on fields using specific functions (expressions) to improve MySQL Query. since ancient times, function indexes are not so complex. So how c

Oracle re-indexing Shell script, SQL script sharing, oracleshell Indexing is a powerful weapon to improve database query performance. Without an index, it is like a library without a book tag. It is more difficult to find a book you want than to climb to the sky. However, in the process of using indexes, especially in the case of batch DML, the corresponding fragments will be generated, and the B-tree heigh

must be used because MySQL does not allow the full length of the indexes to be indexed.The trick is to choose a long enough prefix to ensure high selectivity and not too long (to save space). The prefix should be long enough so that the selectivity of the prefix index is close to the entire column of the index, in other words, the "cardinality" of the prefix should be close to the "cardinality" of the complete column.To determine the appropriate length of the prefix, you need to find a list of

createIndexJob(Configuration conf, String jobName, String batchId) throws IOException, ClassNotFoundException { conf.set(GeneratorJob.BATCH_ID, batchId); Job job = new NutchJob(conf, jobName); // TODO: Figure out why this needs to be here job.getConfiguration().setClass("mapred.output.key.comparator.class", StringComparator.class, RawComparator.class); Collection 2. Execute map-related methods, including setup (), map (), cleanup () public static class IndexerMapper

Basic Principles of Oracle Indexing I. Basic indexing conceptsOracle provides two methods: Read all rows from the table (full table scan), or read a row at a time using ROWID. If you only access 5% of rows in the big data table and use indexes to identify the data blocks to be read, the I/O charges are less. the degree to which indexes improve performance: 1. depends on the Data selectivity 2. distribution

From: http://www.cvchina.info/2012/01/13/kmeans-based-indexing-and-asymmetric-distance-computation-for-ann-search-binary-local-feature-part1/#more-3232 By Herve jegouHamming embedding and weak geometric consistency for large-scale image searchAndProductQuantization for Nearest Neighbor SearchOfInspired to apply kmeans clustering, inverted files, and asypolicric distance computation to the nearest neighbor retrieval of local features in binary form. M

TF-IDF Word Frequency Weighting formula, calculate the weight of each word, and display the weight of each word in each article on the screen.4. Determine the index words based on the input threshold and display the index words on the screen.5. Determine the indexing words based on the input indexing depth and display the indexing words on the screen. The implem

General database search are used SQL like statements, like statements can not use the index, each query is from the first traversal to the last one, query efficiency is extremely low. With general data above 100,000 or too many online, like queries can cause a database crash. This is why many programs provide only the reason for the title search, because if the search content, it is more slow, tens of thousands of data will not move.Mysql Full-text indexing