Version: 0.14.0

SQL DDL

This page describes support for creating and altering tables using SQL across various engines.

Spark SQL

Create table

You can create tables using standard CREATE TABLE syntax, which supports partitioning and passing table properties.

CREATE TABLE [IF NOT EXISTS] [db_name.]table_name
  [(col_name data_type [COMMENT col_comment], ...)]
  [COMMENT table_comment]
  [PARTITIONED BY (col_name, ...)]
  [ROW FORMAT row_format]
  [STORED AS file_format]
  [LOCATION path]
  [TBLPROPERTIES (property_name=property_value, ...)]
  [AS select_statement];

NOTE:

For users running this tutorial locally and have a Spark-Hive(HMS) integration in their environment: If you use default database or if you don't provide [LOCATION path] with the DDL statement, Spark will return java.io.IOException: Mkdirs failed to create file:/user/hive/warehouse/hudi_table/.hoodie error. To get around this, you can follow either of the two options mentioned below:

Create a database i.e. CREATE DATABASE hudidb; and use it i.e. USE hudidb; before running the DDL statement.
Or provide a path using LOCATION keyword to persist the data with the DDL statement.

Create non-partitioned table

Creating a non-partitioned table is as simple as creating a regular table.

-- create a Hudi table
CREATE TABLE IF NOT EXISTS hudi_table (
  id INT,
  name STRING,
  price DOUBLE
) USING hudi;

Create partitioned table

A partitioned table can be created by adding a partitioned by clause. Partitioning helps to organize the data into multiple folders based on the partition columns. It can also help speed up queries and index lookups by limiting the amount of metadata, index and data scanned.

CREATE TABLE IF NOT EXISTS hudi_table_partitioned (
  id BIGINT,
  name STRING,
  dt STRING,
  hh STRING
) USING hudi
TBLPROPERTIES (
  type = 'cow'
)
PARTITIONED BY (dt);

note

You can also create a table partitioned by multiple fields by supplying comma-separated field names. When creating a table partitioned by multiple fields, ensure that you specify the columns in the PARTITIONED BY clause in the same order as they appear in the CREATE TABLE schema. For example, for the above table, the partition fields should be specified as PARTITIONED BY (dt, hh).

Create table with record keys and ordering fields

As discussed here, tables track each record in the table using a record key. Hudi auto-generated a highly compressed key for each new record in the examples so far. If you want to use an existing field as the key, you can set the primaryKey option. Typically, this is also accompanied by configuring a preCombineField option to deal with out-of-order data and potential duplicate records with the same key in the incoming writes.

note

You can choose multiple fields as primary keys for a given table on a need basis. For eg, "primaryKey = 'id, name'", and this materializes a composite key of the two fields, which can be useful for exploring the table.

Here is an example of creating a table using both options. Typically, a field that denotes the time of the event or fact, e.g., order creation time, event generation time etc., is used as the preCombineField. Hudi resolves multiple versions of the same record by ordering based on this field when queries are run on the table.

CREATE TABLE IF NOT EXISTS hudi_table_keyed (
  id INT,
  name STRING,
  price DOUBLE,
  ts BIGINT
) USING hudi
TBLPROPERTIES (
  type = 'cow',
  primaryKey = 'id',
  preCombineField = 'ts'
);

Create table from an external location

Often, Hudi tables are created from streaming writers like the streamer tool, which may later need some SQL statements to run on them. You can create an External table using the location statement.

CREATE TABLE hudi_table_external
USING hudi
LOCATION 'file:///tmp/hudi_table/';

tip

You don't need to specify the schema and any properties except the partitioned columns if they exist. Hudi can automatically recognize the schema and configurations.

Create Table As Select (CTAS)

Hudi supports CTAS(Create table as select) to support initial loads into Hudi tables. To ensure this is done efficiently, even for large loads, CTAS uses bulk insert as the write operation

# create managed parquet table
CREATE TABLE parquet_table
USING parquet
LOCATION 'file:///tmp/parquet_dataset/';

# CTAS by loading data into Hudi table
CREATE TABLE hudi_table_ctas
USING hudi
TBLPROPERTIES (
  type = 'cow',
  preCombineField = 'ts'
)
PARTITIONED BY (dt)
AS SELECT * FROM parquet_table;

You can create a non-partitioned table as well

# create managed parquet table
CREATE TABLE parquet_table
USING parquet
LOCATION 'file:///tmp/parquet_dataset/';

# CTAS by loading data into Hudi table
CREATE TABLE hudi_table_ctas
USING hudi
TBLPROPERTIES (
  type = 'cow',
  preCombineField = 'ts'
)
AS SELECT * FROM parquet_table;

If you prefer explicitly setting the record keys, you can do so by setting primaryKey config in table properties.

CREATE TABLE hudi_table_ctas
USING hudi
TBLPROPERTIES (
  type = 'cow',
  primaryKey = 'id'
)
PARTITIONED BY (dt)
AS
SELECT 1 AS id, 'a1' AS name, 10 AS price, 1000 AS dt;

You can also use CTAS to copy data across external locations

# create managed parquet table
CREATE TABLE parquet_table
USING parquet
LOCATION 'file:///tmp/parquet_dataset/*.parquet';

# CTAS by loading data into hudi table
CREATE TABLE hudi_table_ctas
USING hudi
LOCATION 'file:///tmp/hudi/hudi_tbl/'
TBLPROPERTIES (
  type = 'cow'
)
AS SELECT * FROM parquet_table;

Setting Hudi configs

There are different ways you can pass the configs for a given hudi table.

Using set command

You can use the set command to set any of Hudi's write configs. This will apply to operations across the whole spark session.

set hoodie.insert.shuffle.parallelism = 100;
set hoodie.upsert.shuffle.parallelism = 100;
set hoodie.delete.shuffle.parallelism = 100;

Using table properties

You can also configure table options when creating a table. This will be applied only for the table and override any SET command values.

CREATE TABLE IF NOT EXISTS tableName (
  colName1 colType1,
  colName2 colType2,
  ...
) USING hudi
TBLPROPERTIES (
  primaryKey = '${colName1}',
  type = 'cow',
  ${hoodie.config.key1} = '${hoodie.config.value1}',
  ${hoodie.config.key2} = '${hoodie.config.value2}',
  ....
);

e.g.
CREATE TABLE IF NOT EXISTS hudi_table (
  id BIGINT,
  name STRING,
  price DOUBLE
) USING hudi
TBLPROPERTIES (
  primaryKey = 'id',
  type = 'cow',
  hoodie.cleaner.fileversions.retained = '20',
  hoodie.keep.max.commits = '20'
);

Table Properties

Users can set table properties while creating a table. The important table properties are discussed below.

Parameter Name	Default	Description
type	cow	The table type to create. `type = 'cow'` creates a COPY-ON-WRITE table, while `type = 'mor'` creates a MERGE-ON-READ table. Same as `hoodie.datasource.write.table.type`. More details can be found here
primaryKey	uuid	The primary key field names of the table separated by commas. Same as `hoodie.datasource.write.recordkey.field`. If this config is ignored, hudi will auto-generate primary keys. If explicitly set, primary key generation will honor user configuration.
preCombineField		The pre-combine field of the table. It is used for resolving the final version of the record among multiple versions. Generally, `event time` or another similar column will be used for ordering purposes. Hudi will be able to handle out-of-order data using the preCombine field value.

note

primaryKey, preCombineField, and type and other properties are case-sensitive.

Passing Lock Providers for Concurrent Writers

Hudi requires a lock provider to support concurrent writers or asynchronous table services. Users can pass these table properties into TBLPROPERTIES as well. Below is an example for a Zookeeper based configuration.

-- Properties to use Lock configurations to support Multi Writers
TBLPROPERTIES(
  hoodie.write.lock.zookeeper.url = "zookeeper",
  hoodie.write.lock.zookeeper.port = "2181",
  hoodie.write.lock.zookeeper.lock_key = "tableName",
  hoodie.write.lock.provider = "org.apache.hudi.client.transaction.lock.ZookeeperBasedLockProvider",
  hoodie.write.concurrency.mode = "optimistic_concurrency_control",
  hoodie.write.lock.zookeeper.base_path = "/tableName"
)

Enabling Column Stats / Record Level Index for the table

Hudi provides the ability to leverage rich metadata and index about the table, speed up DMLs and queries. For e.g: collection of column statistics can be enabled to perform quick data skipping or a record-level index can be used to perform fast updates or point lookups using the following table properties.

For more, see Metadata Configurations

TBLPROPERTIES(
  'hoodie.metadata.index.column.stats.enable' = 'true'
  'hoodie.metadata.record.index.enable' = 'true' 
)

Spark Alter Table

Syntax

-- Alter table name
ALTER TABLE oldTableName RENAME TO newTableName;

-- Alter table add columns
ALTER TABLE tableIdentifier ADD COLUMNS(colAndType [, colAndType]);

Examples

--rename to:
ALTER TABLE hudi_table RENAME TO hudi_table_renamed;

--add column:
ALTER TABLE hudi_table ADD COLUMNS(remark STRING);

Modifying Table Properties

Syntax

-- alter table ... set|unset
ALTER TABLE tableIdentifier SET|UNSET TBLPROPERTIES (table_property = 'property_value');

Examples

ALTER TABLE hudi_table SET TBLPROPERTIES (hoodie.keep.max.commits = '10');
ALTER TABLE hudi_table SET TBLPROPERTIES ("note" = "don't drop this table");

ALTER TABLE hudi_table UNSET TBLPROPERTIES IF EXISTS (hoodie.keep.max.commits);
ALTER TABLE hudi_table UNSET TBLPROPERTIES IF EXISTS ('note');

note

Currently, trying to change the column type may throw an error ALTER TABLE CHANGE COLUMN is not supported for changing column colName with oldColType to colName with newColType., due to an open SPARK issue

Alter config options

You can also alter the write config for a table by the ALTER TABLE SET SERDEPROPERTIES

Syntax

-- alter table ... set|unset
ALTER TABLE tableName SET SERDEPROPERTIES ('property' = 'property_value');

Example

 ALTER TABLE hudi_table SET SERDEPROPERTIES ('key1' = 'value1');

Show and drop partitions

Syntax

-- Show partitions
SHOW PARTITIONS tableIdentifier;

-- Drop partition
ALTER TABLE tableIdentifier DROP PARTITION ( partition_col_name = partition_col_val [ , ... ] );

Examples

--Show partition:
SHOW PARTITIONS hudi_table;

--Drop partition：
ALTER TABLE hudi_table DROP PARTITION (dt='2021-12-09', hh='10');

Caveats

Hudi currently has the following limitations when using Spark SQL, to create/alter tables.

ALTER TABLE ... RENAME TO ... is not supported when using AWS Glue Data Catalog as hive metastore as Glue itself does not support table renames.
A new Hudi table created by Spark SQL will by default set hoodie.datasource.write.hive_style_partitioning=true, for ease of use. This can be overridden using table properties.

Flink

Create Catalog

The catalog helps to manage the SQL tables, the table can be shared among sessions if the catalog persists the table definitions. For hms mode, the catalog also supplements the hive syncing options.

Example

CREATE CATALOG hoodie_catalog
  WITH (
    'type'='hudi',
    'catalog.path' = '${catalog default root path}',
    'hive.conf.dir' = '${directory where hive-site.xml is located}',
    'mode'='hms' -- supports 'dfs' mode that uses the DFS backend for table DDLs persistence
  );

Options

Option Name	Required	Default	Remarks
`catalog.path`	true	--	Default path for the catalog's table storage, the path is used to infer the table path automatically, the default table path: `${catalog.path}/${db_name}/${table_name}`
`default-database`	false	default	default database name
`hive.conf.dir`	false	--	The directory where hive-site.xml is located, only valid in `hms` mode
`mode`	false	dfs	Supports `hms` mode that uses HMS to persist the table options
`table.external`	false	false	Whether to create the external table, only valid in `hms` mode

Create Table

The following is an example of creating a Flink table. Read the Flink Quick Start guide for more examples.

CREATE TABLE hudi_table2(
  id int, 
  name string, 
  price double
)
WITH (
'connector' = 'hudi',
'path' = 's3://bucket-name/hudi/',
'table.type' = 'MERGE_ON_READ' -- this creates a MERGE_ON_READ table, default is COPY_ON_WRITE
);

Alter Table

ALTER TABLE tableA RENAME TO tableB;

Supported Types

Spark	Hudi	Notes
boolean	boolean
byte	int
short	int
integer	int
long	long
date	date
timestamp	timestamp
float	float
double	double
string	string
decimal	decimal
binary	bytes
array	array
map	map
struct	struct
char		not supported
varchar		not supported
numeric		not supported
null		not supported
object		not supported

Spark SQL​

Create table​

Create non-partitioned table​

Create partitioned table​

Create table with record keys and ordering fields​

Create table from an external location​

Create Table As Select (CTAS)​

Setting Hudi configs​

Using set command​

Using table properties​

Table Properties​

Passing Lock Providers for Concurrent Writers​

Enabling Column Stats / Record Level Index for the table​

Spark Alter Table​

Modifying Table Properties​

Alter config options​

Show and drop partitions​

Caveats​

Flink​

Create Catalog​

Options​

Create Table​

Alter Table​

Supported Types​

Spark SQL

Create table

Create non-partitioned table

Create partitioned table

Create table with record keys and ordering fields

Create table from an external location

Create Table As Select (CTAS)

Setting Hudi configs

Using set command

Using table properties

Table Properties

Passing Lock Providers for Concurrent Writers

Enabling Column Stats / Record Level Index for the table

Spark Alter Table

Modifying Table Properties

Alter config options

Show and drop partitions

Caveats

Flink

Create Catalog

Options

Create Table

Alter Table

Supported Types