目录
Hive集成表引擎
Hive引擎允许对HDFS Hive表执行 SELECT 查询。目前它支持如下输入格式:
-文本:只支持简单的标量列类型,除了 Binary
- ORC:支持简单的标量列类型,除了char; 只支持 array 这样的复杂类型
- Parquet:支持所有简单标量列类型;只支持 array 这样的复杂类型
创建表
- CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
- (
- name1 [type1] [ALIAS expr1],
- name2 [type2] [ALIAS expr2],
- ...
- ) ENGINE = Hive('thrift://host:port', 'database', 'table');
- PARTITION BY expr
复制代码 表的结构可以与原来的Hive表结构有所不同:
- 列名应该与原来的Hive表相同,但你可以使用这些列中的一些,并以任何顺序,你也可以使用一些从其他列计算的别名列。
- 列类型与原Hive表的列类型保持一致。
- “Partition by expression”应与原Hive表保持一致,“Partition by expression”中的列应在表结构中。
引擎参数
- thrift://host:port — Hive Metastore 地址
- database — 远程数据库名.
- table — 远程数据表名.
使用示例
如何使用HDFS文件系统的本地缓存
我们强烈建议您为远程文件系统启用本地缓存。基准测试显示,如果使用缓存,它的速度会快两倍。
在使用缓存之前,请将其添加到 config.xml- <local_cache_for_remote_fs>
- <enable>true</enable>
- <root_dir>local_cache</root_dir>
- <limit_size>559096952</limit_size>
- <bytes_read_before_flush>1048576</bytes_read_before_flush>
- </local_cache_for_remote_fs>
复制代码
- enable: 开启后,ClickHouse将为HDFS (远程文件系统)维护本地缓存。
- root_dir: 必需的。用于存储远程文件系统的本地缓存文件的根目录。
- limit_size: 必需的。本地缓存文件的最大大小(单位为字节)。
- bytes_read_before_flush: 从远程文件系统下载文件时,刷新到本地文件系统前的控制字节数。缺省值为1MB。
当ClickHouse为远程文件系统启用了本地缓存时,用户仍然可以选择不使用缓存,并在查询中设置 use_local_cache_for_remote_storage = 0, use_local_cache_for_remote_storage 默认为 1。
查询 ORC 输入格式的Hive 表
在 Hive 中建表
- hive > CREATE TABLE `test`.`test_orc`(
- `f_tinyint` tinyint,
- `f_smallint` smallint,
- `f_int` int,
- `f_integer` int,
- `f_bigint` bigint,
- `f_float` float,
- `f_double` double,
- `f_decimal` decimal(10,0),
- `f_timestamp` timestamp,
- `f_date` date,
- `f_string` string,
- `f_varchar` varchar(100),
- `f_bool` boolean,
- `f_binary` binary,
- `f_array_int` array<int>,
- `f_array_string` array<string>,
- `f_array_float` array<float>,
- `f_array_array_int` array<array<int>>,
- `f_array_array_string` array<array<string>>,
- `f_array_array_float` array<array<float>>)
- PARTITIONED BY (
- `day` string)
- ROW FORMAT SERDE
- 'org.apache.hadoop.hive.ql.io.orc.OrcSerde'
- STORED AS INPUTFORMAT
- 'org.apache.hadoop.hive.ql.io.orc.OrcInputFormat'
- OUTPUTFORMAT
- 'org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat'
- LOCATION
- 'hdfs://testcluster/data/hive/test.db/test_orc'
- OK
- Time taken: 0.51 seconds
- hive > insert into test.test_orc partition(day='2021-09-18') select 1, 2, 3, 4, 5, 6.11, 7.22, 8.333, current_timestamp(), current_date(), 'hello world', 'hello world', 'hello world', true, 'hello world', array(1, 2, 3), array('hello world', 'hello world'), array(float(1.1), float(1.2)), array(array(1, 2), array(3, 4)), array(array('a', 'b'), array('c', 'd')), array(array(float(1.11), float(2.22)), array(float(3.33), float(4.44)));
- OK
- Time taken: 36.025 seconds
- hive > select * from test.test_orc;
- OK
- 1 2 3 4 5 6.11 7.22 8 2021-11-05 12:38:16.314 2021-11-05 hello world hello world hello world true hello world [1,2,3] ["hello world","hello world"] [1.1,1.2] [[1,2],[3,4]] [["a","b"],["c","d"]] [[1.11,2.22],[3.33,4.44]] 2021-09-18
- Time taken: 0.295 seconds, Fetched: 1 row(s)
复制代码 在 ClickHouse 中建表
ClickHouse中的表,从上面创建的Hive表中获取数据:- CREATE TABLE test.test_orc
- (
- `f_tinyint` Int8,
- `f_smallint` Int16,
- `f_int` Int32,
- `f_integer` Int32,
- `f_bigint` Int64,
- `f_float` Float32,
- `f_double` Float64,
- `f_decimal` Float64,
- `f_timestamp` DateTime,
- `f_date` Date,
- `f_string` String,
- `f_varchar` String,
- `f_bool` Bool,
- `f_binary` String,
- `f_array_int` Array(Int32),
- `f_array_string` Array(String),
- `f_array_float` Array(Float32),
- `f_array_array_int` Array(Array(Int32)),
- `f_array_array_string` Array(Array(String)),
- `f_array_array_float` Array(Array(Float32)),
- `day` String
- )
- ENGINE = Hive('thrift://localhost:9083', 'test', 'test_orc')
- PARTITION BY day
复制代码- SELECT * FROM test.test_orc settings input_format_orc_allow_missing_columns = 1\G
复制代码- SELECT *
- FROM test.test_orc
- SETTINGS input_format_orc_allow_missing_columns = 1
- Query id: c3eaffdc-78ab-43cd-96a4-4acc5b480658
- Row 1:
- ──────
- f_tinyint: 1
- f_smallint: 2
- f_int: 3
- f_integer: 4
- f_bigint: 5
- f_float: 6.11
- f_double: 7.22
- f_decimal: 8
- f_timestamp: 2021-12-04 04:00:44
- f_date: 2021-12-03
- f_string: hello world
- f_varchar: hello world
- f_bool: true
- f_binary: hello world
- f_array_int: [1,2,3]
- f_array_string: ['hello world','hello world']
- f_array_float: [1.1,1.2]
- f_array_array_int: [[1,2],[3,4]]
- f_array_array_string: [['a','b'],['c','d']]
- f_array_array_float: [[1.11,2.22],[3.33,4.44]]
- day: 2021-09-18
- 1 rows in set. Elapsed: 0.078 sec.
复制代码 查询 Parquest 输入格式的Hive 表
在 Hive 中建表
- hive >
- CREATE TABLE `test`.`test_parquet`(
- `f_tinyint` tinyint,
- `f_smallint` smallint,
- `f_int` int,
- `f_integer` int,
- `f_bigint` bigint,
- `f_float` float,
- `f_double` double,
- `f_decimal` decimal(10,0),
- `f_timestamp` timestamp,
- `f_date` date,
- `f_string` string,
- `f_varchar` varchar(100),
- `f_char` char(100),
- `f_bool` boolean,
- `f_binary` binary,
- `f_array_int` array<int>,
- `f_array_string` array<string>,
- `f_array_float` array<float>,
- `f_array_array_int` array<array<int>>,
- `f_array_array_string` array<array<string>>,
- `f_array_array_float` array<array<float>>)
- PARTITIONED BY (
- `day` string)
- ROW FORMAT SERDE
- 'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe'
- STORED AS INPUTFORMAT
- 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat'
- OUTPUTFORMAT
- 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
- LOCATION
- 'hdfs://testcluster/data/hive/test.db/test_parquet'
- OK
- Time taken: 0.51 seconds
- hive > insert into test.test_parquet partition(day='2021-09-18') select 1, 2, 3, 4, 5, 6.11, 7.22, 8.333, current_timestamp(), current_date(), 'hello world', 'hello world', 'hello world', true, 'hello world', array(1, 2, 3), array('hello world', 'hello world'), array(float(1.1), float(1.2)), array(array(1, 2), array(3, 4)), array(array('a', 'b'), array('c', 'd')), array(array(float(1.11), float(2.22)), array(float(3.33), float(4.44)));
- OK
- Time taken: 36.025 seconds
- hive > select * from test.test_parquet;
- OK
- 1 2 3 4 5 6.11 7.22 8 2021-12-14 17:54:56.743 2021-12-14 hello world hello world hello world true hello world [1,2,3] ["hello world","hello world"] [1.1,1.2] [[1,2],[3,4]] [["a","b"],["c","d"]] [[1.11,2.22],[3.33,4.44]] 2021-09-18
- Time taken: 0.766 seconds, Fetched: 1 row(s)
复制代码 在 ClickHouse 中建表
ClickHouse 中的表, 从上面创建的Hive表中获取数据:- CREATE TABLE test.test_parquet
- (
- `f_tinyint` Int8,
- `f_smallint` Int16,
- `f_int` Int32,
- `f_integer` Int32,
- `f_bigint` Int64,
- `f_float` Float32,
- `f_double` Float64,
- `f_decimal` Float64,
- `f_timestamp` DateTime,
- `f_date` Date,
- `f_string` String,
- `f_varchar` String,
- `f_char` String,
- `f_bool` Bool,
- `f_binary` String,
- `f_array_int` Array(Int32),
- `f_array_string` Array(String),
- `f_array_float` Array(Float32),
- `f_array_array_int` Array(Array(Int32)),
- `f_array_array_string` Array(Array(String)),
- `f_array_array_float` Array(Array(Float32)),
- `day` String
- )
- ENGINE = Hive('thrift://localhost:9083', 'test', 'test_parquet')
- PARTITION BY day
复制代码- SELECT * FROM test.test_parquet settings input_format_parquet_allow_missing_columns = 1\G
复制代码- SELECT *
- FROM test_parquet
- SETTINGS input_format_parquet_allow_missing_columns = 1
- Query id: 4e35cf02-c7b2-430d-9b81-16f438e5fca9
- Row 1:
- ──────
- f_tinyint: 1
- f_smallint: 2
- f_int: 3
- f_integer: 4
- f_bigint: 5
- f_float: 6.11
- f_double: 7.22
- f_decimal: 8
- f_timestamp: 2021-12-14 17:54:56
- f_date: 2021-12-14
- f_string: hello world
- f_varchar: hello world
- f_char: hello world
- f_bool: true
- f_binary: hello world
- f_array_int: [1,2,3]
- f_array_string: ['hello world','hello world']
- f_array_float: [1.1,1.2]
- f_array_array_int: [[1,2],[3,4]]
- f_array_array_string: [['a','b'],['c','d']]
- f_array_array_float: [[1.11,2.22],[3.33,4.44]]
- day: 2021-09-18
- 1 rows in set. Elapsed: 0.357 sec.
复制代码 查询文本输入格式的Hive表
在Hive 中建表
- hive >
- CREATE TABLE `test`.`test_text`(
- `f_tinyint` tinyint,
- `f_smallint` smallint,
- `f_int` int,
- `f_integer` int,
- `f_bigint` bigint,
- `f_float` float,
- `f_double` double,
- `f_decimal` decimal(10,0),
- `f_timestamp` timestamp,
- `f_date` date,
- `f_string` string,
- `f_varchar` varchar(100),
- `f_char` char(100),
- `f_bool` boolean,
- `f_binary` binary,
- `f_array_int` array<int>,
- `f_array_string` array<string>,
- `f_array_float` array<float>,
- `f_array_array_int` array<array<int>>,
- `f_array_array_string` array<array<string>>,
- `f_array_array_float` array<array<float>>)
- PARTITIONED BY (
- `day` string)
- ROW FORMAT SERDE
- 'org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe'
- STORED AS INPUTFORMAT
- 'org.apache.hadoop.mapred.TextInputFormat'
- OUTPUTFORMAT
- 'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'
- LOCATION
- 'hdfs://testcluster/data/hive/test.db/test_text'
- Time taken: 0.1 seconds, Fetched: 34 row(s)
- hive > insert into test.test_text partition(day='2021-09-18') select 1, 2, 3, 4, 5, 6.11, 7.22, 8.333, current_timestamp(), current_date(), 'hello world', 'hello world', 'hello world', true, 'hello world', array(1, 2, 3), array('hello world', 'hello world'), array(float(1.1), float(1.2)), array(array(1, 2), array(3, 4)), array(array('a', 'b'), array('c', 'd')), array(array(float(1.11), float(2.22)), array(float(3.33), float(4.44)));
- OK
- Time taken: 36.025 seconds
- hive > select * from test.test_text;
- OK
- 1 2 3 4 5 6.11 7.22 8 2021-12-14 18:11:17.239 2021-12-14 hello world hello world hello world true hello world [1,2,3] ["hello world","hello world"] [1.1,1.2] [[1,2],[3,4]] [["a","b"],["c","d"]] [[1.11,2.22],[3.33,4.44]] 2021-09-18
- Time taken: 0.624 seconds, Fetched: 1 row(s)
复制代码 在 ClickHouse 中建表
ClickHouse中的表, 从上面创建的Hive表中获取数据:- CREATE TABLE test.test_text
- (
- `f_tinyint` Int8,
- `f_smallint` Int16,
- `f_int` Int32,
- `f_integer` Int32,
- `f_bigint` Int64,
- `f_float` Float32,
- `f_double` Float64,
- `f_decimal` Float64,
- `f_timestamp` DateTime,
- `f_date` Date,
- `f_string` String,
- `f_varchar` String,
- `f_char` String,
- `f_bool` Bool,
- `day` String
- )
- ENGINE = Hive('thrift://localhost:9083', 'test', 'test_text')
- PARTITION BY day
复制代码- SELECT * FROM test.test_text settings input_format_skip_unknown_fields = 1, input_format_with_names_use_header = 1, date_time_input_format = 'best_effort'\G
复制代码- SELECT *
- FROM test.test_text
- SETTINGS input_format_skip_unknown_fields = 1, input_format_with_names_use_header = 1, date_time_input_format = 'best_effort'
- Query id: 55b79d35-56de-45b9-8be6-57282fbf1f44
- Row 1:
- ──────
- f_tinyint: 1
- f_smallint: 2
- f_int: 3
- f_integer: 4
- f_bigint: 5
- f_float: 6.11
- f_double: 7.22
- f_decimal: 8
- f_timestamp: 2021-12-14 18:11:17
- f_date: 2021-12-14
- f_string: hello world
- f_varchar: hello world
- f_char: hello world
- f_bool: true
- day: 2021-09-18
复制代码 资料分享
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