Alter Table Storage

mysql tutorial to modify the table / field to add / delete table index create table test (blob_col blob, index (blob_col (10))); In mysql 5.1, myisam and innodb table prefix can reach 1000 bytes long. Note that the prefix limit should be measured in bytes, while the prefix length in the create table statement is interpreted as the number of characters. Must be considered when specifying the prefix length for columns that use multi-byte character sets. ...

Hive in the official document of the query language has a very detailed description, please refer to: http://wiki.apache.org/hadoop/Hive/LanguageManual, most of the content of this article is translated from this page, Some of the things that need to be noted during the use process are added. Create tablecreate [EXTERNAL] TABLE [IF not EXISTS] table_name [col_name data_t ...

Http://www.aliyun.com/zixun/aggregation/13713.html ">hbase is a distributed, column-oriented open source database, rooted in a Google paper BigTable: A distributed storage system of structured data. HBase is an open-source implementation of Google BigTable, using Hadoop HDFs as its file storage system, using Hadoop mapreduce to handle ...

The following article is mainly about the specific method of implementing a simple and practical optimization of the MySQL database, as well as what specific steps in the actual operation are worthy of our attention. The following article describes the MySQL database is a simple practical optimization of the specific methods to achieve, including how to conduct regular table analysis and inspection, and how to properly optimize the table on a regular basis, the following is a description of the specific program, I hope in your future Learning will be helpful. 1, regular analysis table and checklist analysis table syntax is as follows: ANAL ...

Recently released Hive 0.13 ACID semantic transaction mechanism used to ensure transactional atomicity, consistency and durability at the partition layer, and by opening Zoohttp: //www.aliyun.com/zixun/aggregation/19458.html "> Keeper or in-memory lock mechanism to ensure transaction isolation.Data flow intake, slow changes in dimension, data restatement of these new use cases in the new version has become possible, of course, there are still some deficiencies in the new Hive, Hive ...

Using Lzo compression algorithms in Hadoop reduces the size of the data and the disk read and write time of the data, and Lzo is based on block chunking so that he allows the data to be decomposed into chunk, which is handled in parallel by Hadoop. 　　This feature allows Lzo to become a very handy compression format for Hadoop. Lzo itself is not splitable, so when the data is in text format, the data compressed using Lzo as the job input is a file as a map. But s ...

The logical design of database is a very broad problem. In this paper, the main key design of the table is discussed in the design of MS SQL Server, and the corresponding solutions are given. Primary key design status and problems about database table primary key design, in general, based on business requirements, based on business logic, the formation of primary key. For example, when sales to record sales, generally need two tables, one is the summary description of the sales list, records such as sales number, the total amount of a class of cases, and the other table record of each commodity ...

May 5, BA, Mr. Wei took the Chongqing morning News reporter to see the owner of the stock in the freezer. The production dates of these inventories have been modified. Wei Quan to the reporter to show the owner of the previous inventory of expired food inventory. Chongqing Morning News reporter Hu "boss too abominable, I want to report him!" Call me to change the production date of the frozen goods, still owed my salary.　　"May 5, repeatedly asked Wei Quan (alias), to the Chongqing Morning News 966966 Hotline reported that they have been involved in the food safety incident." Wei Quan once in Dadukou District BA a frozen storehouse when the storehouse tube, in the boss's ...

Logminer is an actual, useful analysis tool that Oracle has provided since 8i, which makes it easy to obtain specific content in Oracle Redo log files (archived log files), Logminer analysis tools are actually made up of a set of PL SQL package and a number of dynamic views that can be used to analyze online logs and archive logs to obtain a database of past detailed, specific operations, very useful. Why do you use Logminer? Mainly for the following reasons: When the database has been mistakenly operated, need not be completed ...

First, the initial understanding of large data seems to be overnight, big data becomes one of the most fashionable words in the IT industry. First of all, big data is not a completely new thing, Google's search service is a typical large data use, according to customer demand, Google real-time from the global mass of digital assets (or digital garbage) ...