Hive存储和压缩结合
官网：+ORC
ORC存储方式的压缩：
| Key | Default | Notes |
|---|---|---|
| orc.compress | ZLIB | high level compression (one of NONE, ZLIB, SNAPPY) |
| orc.compress.size | 262,144 | number of bytes in each compression chunk |
| orc.stripe.size | 67,108,864 | number of bytes in each stripe |
| orc.row.index.stride | 10,000 | number of rows between index entries (must be >= 1000) |
| orc.create.index | true | whether to create row indexes |
| orc.bloom.filter.columns | “” | comma separated list of column names for which bloom filter should be created |
| orc.bloom.filter.fpp | 0.05 | false positive probability for bloom filter (must >0.0 and <1.0) |
- 1）创建一个非压缩的的ORC存储方式
（1）建表语句
create table log_orc_none(
track_time string,
url string,
session_id string,
referer string,
ip string,
end_user_id string,
city_id string
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t'
STORED AS orc tblproperties ("orc.compress"="NONE");
（2）插入数据
insert into table log_orc_none select * from log_text1 ;
（3）查看插入后数据
dfs -du -h /user/hive/warehouse/myhive.db/log_orc_none;
7.7 M /user/hive/warehouse/log_orc_none/123456_0
- 2）创建一个SNAPPY压缩的ORC存储方式
（1）建表语句
create table log_orc_snappy(
track_time string,
url string,
session_id string,
referer string,
ip string,
end_user_id string,
city_id string
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t'
STORED AS orc tblproperties ("orc.compress"="SNAPPY");
（2）插入数据
insert into table log_orc_snappy select * from log_text1 ;
（3）查看插入后数据
dfs -du -h /user/hive/warehouse/myhive.db/log_orc_snappy ;
3.8 M /user/hive/warehouse/log_orc_snappy/123456_0
-
3）上一节中默认创建的ORC存储方式，导入数据后的大小为
2.8 M /user/hive/warehouse/log_orc/123456_0
比Snappy压缩的还小。原因是orc存储文件默认采用ZLIB压缩。比snappy压缩的小。 -
4）存储方式和压缩总结：
在实际的项目开发当中，hive表的数据存储格式一般选择：orc或parquet。压缩方式一般选择snappy。
Hive存储和压缩结合
官网：+ORC
ORC存储方式的压缩：
| Key | Default | Notes |
|---|---|---|
| orc.compress | ZLIB | high level compression (one of NONE, ZLIB, SNAPPY) |
| orc.compress.size | 262,144 | number of bytes in each compression chunk |
| orc.stripe.size | 67,108,864 | number of bytes in each stripe |
| orc.row.index.stride | 10,000 | number of rows between index entries (must be >= 1000) |
| orc.create.index | true | whether to create row indexes |
| orc.bloom.filter.columns | “” | comma separated list of column names for which bloom filter should be created |
| orc.bloom.filter.fpp | 0.05 | false positive probability for bloom filter (must >0.0 and <1.0) |
- 1）创建一个非压缩的的ORC存储方式
（1）建表语句
create table log_orc_none(
track_time string,
url string,
session_id string,
referer string,
ip string,
end_user_id string,
city_id string
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t'
STORED AS orc tblproperties ("orc.compress"="NONE");
（2）插入数据
insert into table log_orc_none select * from log_text1 ;
（3）查看插入后数据
dfs -du -h /user/hive/warehouse/myhive.db/log_orc_none;
7.7 M /user/hive/warehouse/log_orc_none/123456_0
- 2）创建一个SNAPPY压缩的ORC存储方式
（1）建表语句
create table log_orc_snappy(
track_time string,
url string,
session_id string,
referer string,
ip string,
end_user_id string,
city_id string
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t'
STORED AS orc tblproperties ("orc.compress"="SNAPPY");
（2）插入数据
insert into table log_orc_snappy select * from log_text1 ;
（3）查看插入后数据
dfs -du -h /user/hive/warehouse/myhive.db/log_orc_snappy ;
3.8 M /user/hive/warehouse/log_orc_snappy/123456_0
-
3）上一节中默认创建的ORC存储方式，导入数据后的大小为
2.8 M /user/hive/warehouse/log_orc/123456_0
比Snappy压缩的还小。原因是orc存储文件默认采用ZLIB压缩。比snappy压缩的小。 -
4）存储方式和压缩总结：
在实际的项目开发当中，hive表的数据存储格式一般选择：orc或parquet。压缩方式一般选择snappy。
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