jira indexing

data distribution problem. The index can be created only when the density of frequently retrieved data is high. For example, if a table has 0.1 million records and a column does not repeat 90 thousand records, but if the first record is frequently retrieved, its column values that do not repeat are dozens of records, this column is not suitable for indexing. In another case, the overall data density is small, but the density of frequently retrieved d

to the data distribution problem. The index can be created only when the density of frequently retrieved data is high. For example, if a table has 0.1 million records and a column does not repeat 90 thousand records, but if the first record is frequently retrieved, its column values that do not repeat are dozens of records, this column is not suitable for indexing. In another case, the overall data density is small, but the density of frequently retr

though the scope of data retrieval is reduced by index, because the data itself is unordered, when the actual data is extracted from the table, there are frequent positioning problems, which makes SQL Server basically not use indexes in the nonclustered index table to retrieve data. 2, to ensure that the clustered index only Because a clustered index is a row locator that is not a clustered index, if it is not unique, it causes the row locator to contain secondary data and also causes the data

Tags: fuzzy active foreign key ROM set field order name NoIndex creation Occasions:①where the Back field is suitable for indexing②order by sort fields suitable for indexing③ index Overwrite that is, the field you are querying is the index that queries the data directly in the index. For example, select Name,age from man where Name,age itself has an index.④ Table Query (foreign key set index) in a production

Source: http://www.codeproject.com/KB/database/datarow_indexing.aspx Article:Introduction Background When I was developing an application for Pocket PC that used quite large dataset, I wondered where I coshould gain at least some bits of performance. I was filling some data to a tree view control, storing some data else, doing selects from datatable and getting the data from columns of datarows. as you know, you can access the datarow's columns by using either string

Full-Text Search | index Content Summary: Lucene is a Java-based Full-text indexing kit. Java-based Full-text indexing engine Lucene Introduction: About the author and the History of Lucene Implementation of full-text search: A comparison of luene Full-text indexes and database indexes A brief introduction to the mechanism of Chinese word segmentation: A comparison based on lexical library and automatic w

An index is a stable and open information structure. It has eleven features. 1. decomposition Function The data unit in the document (such as the name, organization, phrase, concept, thing name, place name, title, name, word, symbol, etc.) is decomposed one by one, which is the index decomposition function. It is the starting line of indexing and the basis of indexing compilation. Without such a decompositi

;The two types of data stored by BUCKET:INDEX are different directories according to the age organization, called buckets;responsibility-----ByeSearch Head: Front-end searches;Deployment Server: Equivalent to the Configuration Management Center, the other nodes unified management;Forwarder: Responsible for collecting, preprocessing, and forwarding data to indexer (consume and forward it in indexers), in conjunction with the mechanisms that make up flume-like agents and collector; actions include

Crawler crawlers?Pass page quality?In the previous article, we already mentioned an index of the indexing rate. Many websites are too reluctant to do this. "I can't check the data on the site !", As a matter of fact, there is no way to start a lot of work without this indicator. Identify problems from the data and use the data guidance solution to analyze the data verification results. I recently read the simple introduction to data anal

Unfortunately, this is also the case. Relatively speaking, there are some reasons for the decrease in my website's indexing volume, and I have also found these reasons. The decrease in website indexing volume is not a precursor to downgrading. Sometimes it may be because the website has been revised, resulting in invalid links that have previously been indexed, the search leads to the deletion of tokens

The pros and cons of 8.4.5 indexes and how to determine whether an index is needed I believe readers know that indexing can greatly improve the efficiency of data retrieval, so that query executes faster, but probably not every friend knows that indexing greatly improves the efficiency of retrieval, but also brings some negative effects on the database. The following is a simple analysis of the advantages

ArticleDirectory Response results without Indexes Results Use SQL Use tools such as SQL Server Management Studio Basic indexing concepts Indexes and conditions The following table lists the index types available in SQL Server 2005. Basic concepts of index design Material cost considerations Check quota considerations Preface It is very embarrassing to say that I learned three years of data, and I learned the im

Basic SQL server indexing knowledge (1)-basic format of Record DataHere we have collected a series of database indexing knowledge, which is a summary and review of the indexing knowledge. By summing up, you will find that many vague concepts are much clearer in the past. Whether it is cached data information or physically saved information, their basic unit is da

I read a foreign article on the Internet, which introduced the tips for improving Lucene indexing speed and shared it with you. First, let's take a look at the main factors that affect the index: MaxMergeDocs this parameter determines the number of index documents written into the memory. When this number is reached, the memory index is written to the hard disk to generate a new index segment file. Therefore, this parameter is a memory bu. I read a fo

Today, we will use an example to talk about why the website indexing volume does not go up. This is a matter of great concern:Let's show you a website:We can tell you that this website has been in use for more than half a year, but the number of items included shows that it has never exceeded June 5 by one hundred, you may be able to understand that the website has been indexed for more than half a year, but you can check it out. This website is n

Transferred from: http://blog.sina.com.cn/s/blog_4a1f59bf01018apd.htmlAttached to hbase how to create a two-level index and create a two-level index instance: http://www.aboutyun.com/thread-8857-1-1.htmlHuawei two-level index (principle): http://my.oschina.net/u/923508/blog/413129In HBase, the rowkey of the table is sorted by dictionary, and region is shard by the Rowkey setting split point, which is the largest weight of its success by the global, distributed index implemented in this way. Figu

Introduction Full-text indexing enables powerful and fast searching by retrieving each word in a specified database. This article contains best practices for deploying Full-text indexing with Microsoft®exchange Server. Preparing Your Exchange Environment Prepare the Exchange environment to apply to Full-text indexing. The practice is to properly configure t

Oracle Performance Analysis 9: Re-Indexing When an index is faulty, it may cause serious performance problems. index problems include index unavailability and index fragmentation leading to performance degradation. We need some measures to detect the index problems, and solve these problems. This article describes how to locate the index problem and provides a solution.Index unavailable The index is unavailable for many reasons, including:1) The index

What is the principle of database indexing? The management of the MIS system for small and medium-sized enterprises is basically composed of two parts: one is the visual operation at the front end, and the other is the database management at the back end. The management and maintenance of the front-end by the network management includes ensuring smooth network links, handling MIS terminal emergencies, and managing and training operators, this is the m

Label:With its excellent performance, low cost and rich resources, MySQL has become the preferred relational database for most Internet companies. Although performance is good, but the so-called "good Horse with good saddle", how to better use it, has become a required course for development engineers, we often see from the job description such as "Proficient MySQL", "SQL statement optimization", "Understand database principles" and other requirements. We know that the general application system