Hive 4种文件格式

小鱼儿 2022-08-08 12:49 190阅读 0赞

Hive 4种文件格式

原文地址：[http://www.cnblogs.com/Richardzhu/p/3613661.html][http_www.cnblogs.com_Richardzhu_p_3613661.html]

[http://www.iteblog.com/archives/1014][http_www.iteblog.com_archives_1014]

hive文件存储格式包括以下几类：

1、TEXTFILE

2、SEQUENCEFILE

3、RCFILE

4、ORCFILE(0.11以后出现)

其中TEXTFILE为默认格式，建表时不指定默认为这个格式，导入数据时会直接把数据文件拷贝到hdfs上不进行处理；

SEQUENCEFILE，RCFILE，ORCFILE格式的表不能直接从本地文件导入数据，数据要先导入到textfile格式的表中， 然后再从表中用insert导入SequenceFile,RCFile,ORCFile表中。

前提创建环境：

hive 0.8

创建一张testfile\_table表，格式为textfile。

create table if not exists testfile\_table( site string, url  string, pv   bigint, label string) row format delimited fields terminated by '\\t' stored as textfile;

load data local inpath '/app/weibo.txt' overwrite into table textfile\_table;

一、TEXTFILE  
默认格式，数据不做压缩，磁盘开销大，数据解析开销大。  
可结合Gzip、Bzip2使用(系统自动检查，执行查询时自动解压)，但使用这种方式，hive不会对数据进行切分，  
从而无法对数据进行并行操作。  
示例：

![复制代码][copycode.gif]

create table if not exists textfile_table(
    site string,
    url  string,
    pv   bigint,
    label string)
    row format delimited
    fields terminated by '\t'
    stored as textfile;
    插入数据操作：
    set hive.exec.compress.output=true;  
    set mapred.output.compress=true;  
    set mapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec;  
    set io.compression.codecs=org.apache.hadoop.io.compress.GzipCodec;  
    insert overwrite table textfile_table select * from textfile_table;

![复制代码][copycode.gif]

二、SEQUENCEFILE  
SequenceFile是Hadoop API提供的一种二进制文件支持，其具有使用方便、可分割、可压缩的特点。  
SequenceFile支持三种压缩选择：NONE，RECORD，BLOCK。Record压缩率低，一般建议使用BLOCK压缩。  
示例：

![复制代码][copycode.gif]

create table if not exists seqfile_table(
    site string,
    url  string,
    pv   bigint,
    label string)
    row format delimited
    fields terminated by '\t'
    stored as sequencefile;
    插入数据操作：
    set hive.exec.compress.output=true;  
    set mapred.output.compress=true;  
    set mapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec;  
    set io.compression.codecs=org.apache.hadoop.io.compress.GzipCodec;  
    SET mapred.output.compression.type=BLOCK;
    insert overwrite table seqfile_table select * from textfile_table;

![复制代码][copycode.gif]

三、RCFILE  
RCFILE是一种行列存储相结合的存储方式。首先，其将数据按行分块，保证同一个record在一个块上，避免读一个记录需要读取多个block。其次，块数据列式存储，有利于数据压缩和快速的列存取。  
RCFILE文件示例：

![复制代码][copycode.gif]

create table if not exists rcfile_table(
    site string,
    url  string,
    pv   bigint,
    label string)
    row format delimited
    fields terminated by '\t'
    stored as rcfile;
    插入数据操作：
    set hive.exec.compress.output=true;  
    set mapred.output.compress=true;  
    set mapred.output.compression.codec=org.apache.hadoop.io.compress.GzipCodec;  
    set io.compression.codecs=org.apache.hadoop.io.compress.GzipCodec;  
    insert overwrite table rcfile_table select * from textfile_table;

![复制代码][copycode.gif]

四、ORCFILE()  
五、再看TEXTFILE、SEQUENCEFILE、RCFILE三种文件的存储情况：

![复制代码][copycode.gif]

[hadoop@node3 ~]$ hadoop dfs -dus /user/hive/warehouse/*
    hdfs://node1:19000/user/hive/warehouse/hbase_table_1    0
    hdfs://node1:19000/user/hive/warehouse/hbase_table_2    0
    hdfs://node1:19000/user/hive/warehouse/orcfile_table    0
    hdfs://node1:19000/user/hive/warehouse/rcfile_table    102638073
    hdfs://node1:19000/user/hive/warehouse/seqfile_table   112497695
    hdfs://node1:19000/user/hive/warehouse/testfile_table  536799616
    hdfs://node1:19000/user/hive/warehouse/textfile_table  107308067
    [hadoop@node3 ~]$ hadoop dfs -ls /user/hive/warehouse/*/
    -rw-r--r--   2 hadoop supergroup   51328177 2014-03-20 00:42 /user/hive/warehouse/rcfile_table/000000_0
    -rw-r--r--   2 hadoop supergroup   51309896 2014-03-20 00:43 /user/hive/warehouse/rcfile_table/000001_0
    -rw-r--r--   2 hadoop supergroup   56263711 2014-03-20 01:20 /user/hive/warehouse/seqfile_table/000000_0
    -rw-r--r--   2 hadoop supergroup   56233984 2014-03-20 01:21 /user/hive/warehouse/seqfile_table/000001_0
    -rw-r--r--   2 hadoop supergroup  536799616 2014-03-19 23:15 /user/hive/warehouse/testfile_table/weibo.txt
    -rw-r--r--   2 hadoop supergroup   53659758 2014-03-19 23:24 /user/hive/warehouse/textfile_table/000000_0.gz
    -rw-r--r--   2 hadoop supergroup   53648309 2014-03-19 23:26 /user/hive/warehouse/textfile_table/000001_1.gz

![复制代码][copycode.gif]

总结:  
相比TEXTFILE和SEQUENCEFILE，RCFILE由于列式存储方式，数据加载时性能消耗较大，但是具有较好的压缩比和查询响应。数据仓库的特点是一次写入、多次读取，因此，整体来看，RCFILE相比其余两种格式具有较明显的优势。

##### 一、定义 #####

ORC File，它的全名是Optimized Row Columnar (ORC) file，其实就是对RCFile做了一些优化。据官方文档介绍，这种文件格式可以提供一种高效的方法来存储Hive数据。它的设计目标是来克服Hive其他格式的缺陷。运用ORC File可以提高Hive的读、写以及处理数据的性能。  
和RCFile格式相比，ORC File格式有以下优点：  
　　(1)、每个task只输出单个文件，这样可以减少NameNode的负载；  
　　(2)、支持各种复杂的数据类型，比如： datetime, decimal, 以及一些复杂类型(struct, list, map, and union)；  
　　(3)、在文件中存储了一些轻量级的索引数据；  
　　(4)、基于数据类型的块模式压缩：a、integer类型的列用行程长度编码(run-length encoding);b、String类型的列用字典编码(dictionary encoding)；  
　　(5)、用多个互相独立的RecordReaders并行读相同的文件；  
　　(6)、无需扫描markers就可以分割文件；  
　　(7)、绑定读写所需要的内存；  
　　(8)、metadata的存储是用 Protocol Buffers的，所以它支持添加和删除一些列。

##### 二、ORC File文件结构 #####

ORC File包含一组组的行数据，称为stripes，除此之外，ORC File的file footer还包含一些额外的辅助信息。在ORC File文件的最后，有一个被称为postscript的区，它主要是用来存储压缩参数及压缩页脚的大小。  
在默认情况下，一个stripe的大小为250MB。大尺寸的stripes使得从HDFS读数据更高效。  
　　在file footer里面包含了该ORC File文件中stripes的信息，每个stripe中有多少行，以及每列的数据类型。当然，它里面还包含了列级别的一些聚合的结果，比如：count, min, max, and sum。下图显示出可ORC File文件结构：

[![ORC File Format][]][ORC File Format]

ORC File Format

##### 三、Stripe结构 #####

从上图我们可以看出，每个Stripe都包含index data、row data以及stripe footer。Stripe footer包含流位置的目录；Row data在表扫描的时候会用到。  
　　Index data包含每列的最大和最小值以及每列所在的行。行索引里面提供了偏移量，它可以跳到正确的压缩块位置。具有相对频繁的行索引，使得在stripe中快速读取的过程中可以跳过很多行，尽管这个stripe的大小很大。在默认情况下，最大可以跳过10000行。拥有通过过滤谓词而跳过大量的行的能力，你可以在表的 secondary keys 进行排序，从而可以大幅减少执行时间。比如你的表的主分区是交易日期，那么你可以对次分区（state、zip code以及last name）进行排序。

##### 四、Hive里面如何用ORCFile #####

在建Hive表的时候我们就应该指定文件的存储格式。所以你可以在Hive QL语句里面指定用ORCFile这种文件格式，如下：

<table style="border-spacing:0px; font-size:1em!important; border:0px!important; width:auto!important; margin:0px!important; padding:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; line-height:1.2em!important; direction:ltr!important; border-collapse:collapse!important; background:none!important"> 
 <tbody style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
  <tr style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
   <td style="border:0px!important; padding:0px!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; color:rgb(7,81,154)!important; background:none!important"> <code style="color:rgb(221,17,68); white-space:nowrap; padding:0px 0.3em 0px 0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; direction:ltr!important; display:block!important; background:none!important">1</code></td> 
   <td style="margin:0px!important; border-width:0px 0px 0px 3px!important; padding:0px 0px 0px 0.5em!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; background:none!important"> <code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">CREATE</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">TABLE</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">... STORED&nbsp;</code><code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">AS</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">ORC</code></td> 
  </tr> 
 </tbody> 
</table>

<table style="border-spacing:0px; font-size:1em!important; border:0px!important; width:auto!important; margin:0px!important; padding:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; line-height:1.2em!important; direction:ltr!important; border-collapse:collapse!important; background:none!important"> 
 <tbody style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
  <tr style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
   <td style="border:0px!important; padding:0px!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; color:rgb(7,81,154)!important; background:none!important"> <code style="color:rgb(221,17,68); white-space:nowrap; padding:0px 0.3em 0px 0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; direction:ltr!important; display:block!important; background:none!important">3</code></td> 
   <td style="margin:0px!important; border-width:0px 0px 0px 3px!important; padding:0px 0px 0px 0.5em!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; background:none!important"> <code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">ALTER</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">TABLE</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">... [PARTITION partition_spec]&nbsp;</code><code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">SET</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">FILEFORMAT ORC</code></td> 
  </tr> 
 </tbody> 
</table>

<table style="border-spacing:0px; font-size:1em!important; border:0px!important; width:auto!important; margin:0px!important; padding:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; line-height:1.2em!important; direction:ltr!important; border-collapse:collapse!important; background:none!important"> 
 <tbody style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
  <tr style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
   <td style="border:0px!important; padding:0px!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; color:rgb(7,81,154)!important; background:none!important"> <code style="color:rgb(221,17,68); white-space:nowrap; padding:0px 0.3em 0px 0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; direction:ltr!important; display:block!important; background:none!important">5</code></td> 
   <td style="margin:0px!important; border-width:0px 0px 0px 3px!important; padding:0px 0px 0px 0.5em!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; background:none!important"> <code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">SET</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">hive.</code><code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">default</code><code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">.fileformat=Orc</code></td> 
  </tr> 
 </tbody> 
</table>

所有关于ORCFile的参数都是在Hive QL语句的TBLPROPERTIES字段里面出现，他们是：

<table style=""> 
 <tbody> 
  <tr> 
   <th colspan="" style="">Key</th> 
   <th colspan="" style="">Default</th> 
   <th colspan="" style="">Notes</th> 
  </tr> 
  <tr> 
   <td colspan="" style="border-style:solid solid solid none; border-top-width:1px; border-top-color:rgb(204,204,204); padding:5px 10px; text-align:center; border-bottom-width:1px; border-bottom-color:rgb(221,221,221); border-right-width:1px; border-right-color:rgb(221,221,221)"> orc.compress</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> ZLIB</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> high level compression (one of NONE, ZLIB, SNAPPY)</td> 
  </tr> 
  <tr> 
   <td colspan="" style="border-style:solid solid solid none; border-top-width:1px; border-top-color:rgb(204,204,204); padding:5px 10px; text-align:center; border-bottom-width:1px; border-bottom-color:rgb(221,221,221); border-right-width:1px; border-right-color:rgb(221,221,221)"> orc.compress.size</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> 262,144</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> number of bytes in each compression chunk</td> 
  </tr> 
  <tr> 
   <td colspan="" style="border-style:solid solid solid none; border-top-width:1px; border-top-color:rgb(204,204,204); padding:5px 10px; text-align:center; border-bottom-width:1px; border-bottom-color:rgb(221,221,221); border-right-width:1px; border-right-color:rgb(221,221,221)"> orc.stripe.size</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> 268435456</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> number of bytes in each stripe</td> 
  </tr> 
  <tr> 
   <td colspan="" style="border-style:solid solid solid none; border-top-width:1px; border-top-color:rgb(204,204,204); padding:5px 10px; text-align:center; border-bottom-width:1px; border-bottom-color:rgb(221,221,221); border-right-width:1px; border-right-color:rgb(221,221,221)"> orc.row.index.stride</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> 10,000</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> number of rows between index entries (must be &gt;= 1000)</td> 
  </tr> 
  <tr> 
   <td colspan="" style="border-style:solid solid solid none; border-top-width:1px; border-top-color:rgb(204,204,204); padding:5px 10px; text-align:center; border-bottom-width:1px; border-bottom-color:rgb(221,221,221); border-right-width:1px; border-right-color:rgb(221,221,221)"> orc.create.index</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> true</td> 
   <td colspan="" style="border-width:1px; border-style:solid; border-color:rgb(204,204,204) rgb(221,221,221) rgb(221,221,221) rgb(204,204,204); padding:5px 10px; text-align:center"> whether to create row indexes</td> 
  </tr> 
 </tbody> 
</table>

下面的例子是建立一个没有启用压缩的ORCFile的表

[查看源代码][Link 1]

[打印][Link 2] [帮助][Link 3]

<table style="border-spacing:0px; font-size:1em!important; border:0px!important; width:auto!important; margin:0px!important; padding:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; line-height:1.2em!important; direction:ltr!important; border-collapse:collapse!important; background:none!important"> 
 <tbody style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
  <tr style="margin:0px!important; padding:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-size:1em!important; direction:ltr!important; background:none!important"> 
   <td style="border:0px!important; padding:0px!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; color:rgb(7,81,154)!important; background:none!important"> <code style="color:rgb(221,17,68); white-space:nowrap; padding:0px 0.3em 0px 0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:1.7em!important; line-height:1.2em!important; direction:ltr!important; display:block!important; background:none!important">7</code></td> 
   <td style="margin:0px!important; border-width:0px 0px 0px 3px!important; padding:0px 0px 0px 0.5em!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:1em!important; direction:ltr!important; background:none!important"> <code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">) stored&nbsp;</code><code style="white-space:nowrap; padding:0px!important; color:rgb(0,102,153)!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; font-weight:bold!important; direction:ltr!important; display:inline!important; background:none!important">as</code>&nbsp;<code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">orc tblproperties (</code><code style="white-space:nowrap; padding:0px!important; color:blue!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">"orc.compress"</code><code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">=</code><code style="white-space:nowrap; padding:0px!important; color:blue!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">"NONE"</code><code style="white-space:nowrap; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; border:0px!important; font-size:1em!important; margin:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.2em!important; direction:ltr!important; display:inline!important; background:none!important">);</code></td> 
  </tr> 
 </tbody> 
</table>

[http_www.cnblogs.com_Richardzhu_p_3613661.html]: http://www.cnblogs.com/Richardzhu/p/3613661.html
[http_www.iteblog.com_archives_1014]: http://www.iteblog.com/archives/1014
[copycode.gif]: /images/20220805/2ac517d5460544d8a67a40291dece46a.png
[ORC File Format]: /images/20220805/578c032d6d494bb6971d4150392605e0.png
[Link 1]: http://www.iteblog.com/archives/1014#viewSource
[Link 2]: http://www.iteblog.com/archives/1014#printSource
[Link 3]: http://www.iteblog.com/archives/1014#about