hive helper

Overview As long as the correct file types and compression types (such as Textfile+gzip, sequencefile+snappy, etc.) are configured, hive can read and parse data as expected and provide SQL functionality. The structure of the sequencefile itself has been designed to compress content. So for the Sequencefile file compression, not the Sequencefile file, and then the file compression. Instead, the Content field is compressed when the Sequencefile file is

Hive simple instructions for use, hive simple instructions for use I usage: Hive: Start hive The command must end with a semicolon and tell hive to execute the command immediately, case insensitive. Show tables; View tables Desc tablename; view the columns in the tabl

Use Cases of hive concurrency Model Concurrency support (http://issues.apache.org/jira/browse/HIVE-1293) is a must for databases and Their Use Cases are well understood. At least, we should try to support concurrent reading and writing. It is useful to add several locks that are currently locked. There is no direct requirement to add an API to explicitly obtain the lock. Therefore, all locks are obtained i

default database table is stored in the/user/hive/warehouse directory.(1) TextfileTextfile is the default format and is stored as a row store. Data is not compressed, disk overhead is large, data parsing cost is large.(2) SequencefileSequencefile is a binary file support provided by the Hadoop API, which is easy to use, can be segmented, and compressible. Sequencefile supports three types of compression options: NONE, RECORD, BLOCK. The record compre

Describe:Hive Table Pms.cross_sale_path is established with the date as the partition, the HDFs directory/user/pms/workspace/ouyangyewei/testusertrack/job1output/ The data on the Crosssale, written on the $yesterday partition of the tableTable structure:HIVE-E "Set Mapred.job.queue.name=pms;drop table if exists pms.cross_sale_path;create external table Pms.cross_sale_ Path (track_id string,track_time string,session_id string,gu_id string,end_user_id string,page_category_id bigint, algorithm_id i

Read the table structure in hive. This article contains the table class, the field class is used to encapsulate the table structure, and it will be OK after a rough look. (Change the code format) 1. Table class Public class table { Private string tablename; Private list Public table (){ } Public table (string tablename, list This. tablename = tablename; This. Field = field; } Public String gettablename (){ Return tablename; } Public void setta

Tags: Word exist Derby configuration driver data pre XML color / /server110:3306/hive?createdatabaseifnotexist=true Hive replaces default Derby's hive-site.xml configuration with MySQL as metadata

Transferred from: http://kb.cnblogs.com/page/102191/ASP. NET MVC 3 supports a new view engine option named "Razor" (in addition to continuing to support/strengthen the existing. aspx view engine). When writing a view template, razor minimizes the number of characters and keystrokes required and guarantees a fast, unobstructed coding workflow.Unlike most templates, with the help of razor, you do not need to interrupt code writing just to label the beginning and end of the server-side code block i

Hive The main features of each version Introduction to Key new Feature of Hive versions The website downloads the introduction of the page Hive Foundationcommand-line interface The user interface provided by hive includes: CLI, Client, WebUI several ways, we usually mainly use CLI, the future cluster upgrade may have

Hive file Format1, TextfileDefault file formatData does not compress, disk overhead, data parsing overhead, can be combined with gzip, BZIP2 use (System Auto-detection, automatic decompression when executing queries)Data is not segmented by hive, so data cannot be manipulated in parallelTo create a command:2, Sequencefileis a binary file support provided by the Hadoop APIEasy to use, divisible, compressible

Transfer from http://superlxw1234.iteye.com/blog/1582880First, control the number of maps in the hive task:1. Typically, the job produces one or more map tasks through the directory of input.The main determinants are: The total number of input files, the file size of input, the size of the file block set by the cluster (currently 128M, can be set dfs.block.size in hive; command to see, this parameter can no

Here list common operations, more refer to https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-Create%2FDrop%2FTruncateTable Simple Table Creation Create Table table_name (ID int, dtdontquery string, name string) Create a partitioned table Create Table table_name (ID int, dtdontquery string, name string) partitioned by (date string) A table can have one or more partitions. Each partition exists in a

Hive Installation (hadoop2.6.0 hive 1.2.1)Website address: http://hive.apache.org/downloads.html three different modesInline mode: Metadata is kept in the inline derby mode, allowing only one session to connect to local standalone mode: Install MySQL locally, bar metadata in MySQL remote mode: Meta data placed in remote MySQL database 1. Embedded mode: (1), modify/home/lin/hadoop/apache-

Hive in layman 's1. What is Hive1) What is hive?Here is an introduction to the Hive wiki:Hive is a data warehouse infrastructure built on top of Hadoop. IT provides tools to enable easy data ETL, a mechanism to put structures on the data, and the capability to querying and a Nalysis of large data sets stored in Hadoop files.