Paimon catalog

Introduction

Apache Gravitino provides the ability to manage Apache Paimon metadata.

Requirements

info

Builds with Apache Paimon 0.8.0.

Catalog

Catalog capabilities

• Works as a catalog proxy, supporting FilesystemCatalog.

• Supports DDL operations for Paimon schemas and tables.

• Doesn't support JdbcCatalog and HiveCatalog catalog backend now.

• Doesn't support alterSchema.

Catalog properties

Property name	Description	Default value	Required	Since Version
catalog-backend	Catalog backend of Gravitino Paimon catalog. Only supports filesystem now.	(none)	Yes	0.6.0
uri	The URI configuration of the Paimon catalog. thrift://127.0.0.1:9083 or jdbc:postgresql://127.0.0.1:5432/db_name or jdbc:mysql://127.0.0.1:3306/metastore_db. It is optional for FilesystemCatalog.	(none)	required if the value of catalog-backend is not filesystem.	0.6.0
warehouse	Warehouse directory of catalog. file:///user/hive/warehouse-paimon/ for local fs or hdfs://namespace/hdfs/path for HDFS.	(none)	Yes	0.6.0
authentication.type	The type of authentication for Paimon catalog backend, currently Gravitino only supports Kerberos and simple.	simple	No	0.6.0
authentication.kerberos.principal	The principal of the Kerberos authentication.	(none)	required if the value of authentication.type is Kerberos.	0.6.0
authentication.kerberos.keytab-uri	The URI of The keytab for the Kerberos authentication.	(none)	required if the value of authentication.type is Kerberos.	0.6.0
authentication.kerberos.check-interval-sec	The check interval of Kerberos credential for Paimon catalog.	60	No	0.6.0
authentication.kerberos.keytab-fetch-timeout-sec	The fetch timeout of retrieving Kerberos keytab from authentication.kerberos.keytab-uri.	60	No	0.6.0

Any properties not defined by Gravitino with gravitino.bypass. prefix will pass to Paimon catalog properties and HDFS configuration. For example, if specify gravitino.bypass.table.type, table.type will pass to Paimon catalog properties.

Catalog operations

Please refer to Manage Relational Metadata Using Gravitino for more details.

Schema

Schema capabilities

• Supporting createSchema, dropSchema, loadSchema and listSchema.

• Supporting cascade drop schema.

• Doesn't support alterSchema.

Schema properties

• Doesn't support specify location and store any schema properties when createSchema for FilesystemCatalog.
• Doesn't return any schema properties when loadSchema for FilesystemCatalog.
• Doesn't support store schema comment for FilesystemCatalog.

Schema operations

Please refer to Manage Relational Metadata Using Gravitino for more details.

Table

Table capabilities

• Supporting createTable, purgeTable, alterTable, loadTable and listTable.

• Supporting Column default value through table properties, such as fields.{columnName}.default-value, not column expression.

• Doesn't support dropTable.

• Doesn't support table distribution and sort orders.

info

Gravitino Paimon Catalog does not support dropTable, because the dropTable in Paimon will both remove the table metadata and the table location from the file system and skip the trash, we should use purgeTable instead in Gravitino.

info

Paimon does not support auto increment column.

Table changes

• RenameTable
• AddColumn
• DeleteColumn
• RenameColumn
• UpdateColumnComment
• UpdateColumnNullability
• UpdateColumnPosition
• UpdateColumnType
• UpdateComment
• SetProperty
• RemoveProperty

Table partitions

• Only supports Identity partitions, such as day, hour, etc.

Please refer to Paimon DDL Create Table for more details.

Table sort orders

• Doesn't support table sort orders.

Table distributions

• Doesn't support table distributions.

Table indexes

• Only supports primary key Index.

info

We cannot specify more than one primary key Index, and a primary key Index can contain multiple fields as a joint primary key.

info

Paimon Table primary key constraint should not be same with partition fields, this will result in only one record in a partition.

Table column types

Gravitino Type	Apache Paimon Type
Sturct	Row
Map	Map
Array	Array
Boolean	Boolean
Byte	TinyInt
Short	SmallInt
Integer	Int
Long	BigInt
Float	Float
Double	Double
Decimal	Decimal
String	VarChar(Integer.MAX_VALUE)
VarChar	VarChar
FixedChar	Char
Date	Date
Time	Time
TimestampType withZone	LocalZonedTimestamp
TimestampType withoutZone	Timestamp
Binary	Binary
Fixed	VarBinary

info

Gravitino doesn't support Paimon MultisetType type.

Table properties

You can pass Paimon table properties to Gravitino when creating a Paimon table.

The Gravitino server doesn't allow passing the following reserved fields.

Configuration item	Description
comment	The table comment.
owner	The table owner.
bucket-key	The table bucket-key.
merge-engine	The table merge-engine.
sequence.field	The table sequence.field.
rowkind.field	The table rowkind.field.
primary-key	The table primary-key.
partition	The table partition.

Table operations

Please refer to Manage Relational Metadata Using Gravitino for more details.

HDFS configuration

You can place core-site.xml and hdfs-site.xml in the catalogs/lakehouse-paimon/conf directory to automatically load as the default HDFS configuration.

caution

When reading and writing to HDFS, the Gravitino server can only operate as the specified Kerberos user and doesn't support proxying to other Kerberos users now.