Iceberg

Iceberg

使用限制

支持 Iceberg V1/V2 表格式。
V2 格式仅支持 Position Delete 方式，不支持 Equality Delete。

创建 Catalog

基于Hive Metastore创建Catalog

和 Hive Catalog 基本一致，这里仅给出简单示例。其他示例可参阅 Hive Catalog。

CREATE CATALOG iceberg PROPERTIES (
    'type'='hms',
    'hive.metastore.uris' = 'thrift://172.21.0.1:7004',
    'hadoop.username' = 'hive',
    'dfs.nameservices'='your-nameservice',
    'dfs.ha.namenodes.your-nameservice'='nn1,nn2',
    'dfs.namenode.rpc-address.your-nameservice.nn1'='172.21.0.2:4007',
    'dfs.namenode.rpc-address.your-nameservice.nn2'='172.21.0.3:4007',
    'dfs.client.failover.proxy.provider.your-nameservice'='org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider'
);

基于Iceberg API创建Catalog

使用Iceberg API访问元数据的方式，支持Hadoop File System、Hive、REST、Glue、DLF等服务作为Iceberg的Catalog。

Hadoop Catalog

CREATE CATALOG iceberg_hadoop PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type' = 'hadoop',
    'warehouse' = 'hdfs://your-host:8020/dir/key'
);

CREATE CATALOG iceberg_hadoop_ha PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type' = 'hadoop',
    'warehouse' = 'hdfs://your-nameservice/dir/key',
    'dfs.nameservices'='your-nameservice',
    'dfs.ha.namenodes.your-nameservice'='nn1,nn2',
    'dfs.namenode.rpc-address.your-nameservice.nn1'='172.21.0.2:4007',
    'dfs.namenode.rpc-address.your-nameservice.nn2'='172.21.0.3:4007',
    'dfs.client.failover.proxy.provider.your-nameservice'='org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider'
);

CREATE CATALOG iceberg_s3 PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type' = 'hadoop',
    'warehouse' = 's3://bucket/dir/key',
    's3.endpoint' = 's3.us-east-1.amazonaws.com',
    's3.access_key' = 'ak',
    's3.secret_key' = 'sk'
);

Hive Metastore

CREATE CATALOG iceberg PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type'='hms',
    'hive.metastore.uris' = 'thrift://172.21.0.1:7004',
    'hadoop.username' = 'hive',
    'dfs.nameservices'='your-nameservice',
    'dfs.ha.namenodes.your-nameservice'='nn1,nn2',
    'dfs.namenode.rpc-address.your-nameservice.nn1'='172.21.0.2:4007',
    'dfs.namenode.rpc-address.your-nameservice.nn2'='172.21.0.3:4007',
    'dfs.client.failover.proxy.provider.your-nameservice'='org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider'
);

AWS Glue

连接Glue时，如果是在非EC2环境，需要将EC2环境里的 ~/.aws 目录拷贝到当前环境里。也可以下载AWS Cli工具进行配置，这种方式也会在当前用户目录下创建.aws目录。

CREATE CATALOG glue PROPERTIES (
    "type"="iceberg",
    "iceberg.catalog.type" = "glue",
    "glue.endpoint" = "https://glue.us-east-1.amazonaws.com",
    "glue.access_key" = "ak",
    "glue.secret_key" = "sk"
);

Iceberg 属性详情参见 Iceberg Glue Catalog
如果在AWS服务（如EC2）中，不填写Credentials相关信息（glue.access_key和glue.secret_key），Doris就会使用默认的DefaultAWSCredentialsProviderChain，它会读取系统环境变量或者InstanceProfile中配置的属性。

阿里云 DLF

参见阿里云DLF Catalog配置

REST Catalog

该方式需要预先提供REST服务，用户需实现获取Iceberg元数据的REST接口。

CREATE CATALOG iceberg PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type'='rest',
    'uri' = 'http://172.21.0.1:8181'
);

如果使用HDFS存储数据，并开启了高可用模式，还需在Catalog中增加HDFS高可用配置：

CREATE CATALOG iceberg PROPERTIES (
    'type'='iceberg',
    'iceberg.catalog.type'='rest',
    'uri' = 'http://172.21.0.1:8181',
    'dfs.nameservices'='your-nameservice',
    'dfs.ha.namenodes.your-nameservice'='nn1,nn2',
    'dfs.namenode.rpc-address.your-nameservice.nn1'='172.21.0.1:8020',
    'dfs.namenode.rpc-address.your-nameservice.nn2'='172.21.0.2:8020',
    'dfs.client.failover.proxy.provider.your-nameservice'='org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider'
);

Google Dataproc Metastore

CREATE CATALOG iceberg PROPERTIES (
    "type"="iceberg",
    "iceberg.catalog.type"="hms",
    "hive.metastore.uris" = "thrift://172.21.0.1:9083",
    "gs.endpoint" = "https://storage.googleapis.com",
    "gs.region" = "us-east-1",
    "gs.access_key" = "ak",
    "gs.secret_key" = "sk",
    "use_path_style" = "true"
);

hive.metastore.uris: Dataproc Metastore 服务开放的接口，在 Metastore 管理页面获取：Dataproc Metastore Services.

Iceberg On Object Storage

若数据存放在S3上，properties中可以使用以下参数：

"s3.access_key" = "ak"
"s3.secret_key" = "sk"
"s3.endpoint" = "s3.us-east-1.amazonaws.com"
"s3.region" = "us-east-1"

数据存放在阿里云OSS上：

"oss.access_key" = "ak"
"oss.secret_key" = "sk"
"oss.endpoint" = "oss-cn-beijing-internal.aliyuncs.com"
"oss.region" = "oss-cn-beijing"

数据存放在腾讯云COS上：

"cos.access_key" = "ak"
"cos.secret_key" = "sk"
"cos.endpoint" = "cos.ap-beijing.myqcloud.com"
"cos.region" = "ap-beijing"

数据存放在华为云OBS上：

"obs.access_key" = "ak"
"obs.secret_key" = "sk"
"obs.endpoint" = "obs.cn-north-4.myhuaweicloud.com"
"obs.region" = "cn-north-4"

列类型映射

和 Hive Catalog 一致，可参阅 Hive Catalog 中 列类型映射 一节。

Time Travel

支持读取 Iceberg 表指定的 Snapshot。

每一次对iceberg表的写操作都会产生一个新的快照。

默认情况下，读取请求只会读取最新版本的快照。

可以使用 FOR TIME AS OF 和 FOR VERSION AS OF 语句，根据快照 ID 或者快照产生的时间读取历史版本的数据。示例如下：

SELECT * FROM iceberg_tbl FOR TIME AS OF "2022-10-07 17:20:37";

SELECT * FROM iceberg_tbl FOR VERSION AS OF 868895038966572;

另外，可以使用 iceberg_meta 表函数查询指定表的 snapshot 信息。