Data and Schema Import

Migrating schemas and data from JDBC-compatible databases or Apache Iceberg into a GridGain 8 cluster with the Data and Schema Import wizard.

The Data and Schema Import feature lets you migrate database schemas and data from external JDBC-compatible databases (PostgreSQL, MySQL, and others) or Apache Iceberg into a GridGain 8 cluster. It generates DDL statements for table creation and COPY statements for data migration.

You can open Import Schema/Import Data from:

• The Import Schemas menu option, accessible via the user profile menu.

• The Queries screen — via the Import Schema/Import Data action button.

The import process consists of up to six steps:

1. Connection

2. Schemas & Tables

3. Table Settings

4. Column Settings

5. Data Import

6. Overview

You can open Data Import directly from the Queries screen without going through the schema setup steps. Do this when the target tables already exist in the GridGain cluster and you only need to load or reload data.

Connection

Configure how Control Center connects to the source database.

Control Center Connector

Select the Control Center Connector through which the connection to the cluster will be established. The connector must have network access to the source database.

Connection Type

Choose the type of source system:

• JDBC — for relational databases such as PostgreSQL, MySQL, MariaDB, and other JDBC-compatible databases.

• Apache Iceberg — for Iceberg tables accessed via a REST or JDBC catalog.

JDBC Connection

Connection step — JDBC

When JDBC is selected, provide the following:

Field	Description
Driver JAR	Select a preloaded driver JAR from the list, or upload a custom one.
Driver class	The JDBC driver class name. Populated automatically when a known driver is selected.
JDBC URL	The JDBC connection string for the source database (for example, jdbc:mysql://localhost:3307).
Username / Password	Optional credentials for the source database. Passwords are never stored by Control Center.

Preloaded JDBC drivers are provided for MariaDB, MySQL and PostgreSQL. When using a custom driver, ensure the connector.schema-import.jdbc-drivers configuration property points to the directory containing the JAR file.

Click Test Connection to verify that the connection settings are correct before proceeding.

If the connection test fails, an error is shown in the right-side Summary panel. Review the JDBC URL, credentials, and network accessibility of the source database.

Apache Iceberg Connection

When Apache Iceberg is selected, choose the catalog type:

• JDBC — connect via a JDBC-backed Iceberg catalog.

• REST — connect via an Iceberg REST catalog endpoint.

Connection step — Apache Iceberg REST

For REST catalogs, provide the following:

Field	Description
REST URL	The base URL of the Iceberg REST catalog (for example, http://localhost:8181).
Warehouse path	Path to the Iceberg warehouse (for example, s3://iceberg.warehouse).
Catalog name	The name of the catalog to connect to.
ID implementation	The FileIO implementation to use: HadoopFileIO or S3FileIO.
Username / Password	Optional credentials. Passwords are never stored.

Click Test Connection to verify the Iceberg catalog is reachable before proceeding.

Schemas & Tables

After a successful connection, Control Center lists all schemas and tables available in the source database.

1. In the Configuration name field, enter a name for this import configuration. The name is used to save your progress and identify this import job.

2. Expand schemas in the tree and select the tables you want to import. Use Select all to select everything, or expand individual schemas to pick specific tables.

At least one schema and one table must be selected to proceed.

Schemas & Tables step

The imported schema will be loaded into one of the existing GridGain 8 clusters.

Table Settings

Configure GridGain-specific storage settings for each selected table, choose the target cluster, and define how to handle naming conflicts.

Target Cluster

Select the GridGain 8 cluster into which the schema will be imported. Only clusters in an active state are available. If no active cluster is available, click Save and Close to save your configuration and resume the import when a cluster becomes available.

Conflict Resolution

If a schema with the same name already exists in the target cluster, select how to proceed:

• Merge with existing schema is set by default. When selected, the imported tables are added to the existing schema. Existing tables and data are not affected.

  

  Conflict Resolution
• When Rename schema is selected, the imported schema is renamed by adding a configurable prefix and/or suffix, avoiding any conflict with the existing schema.

  

  Table Settings step — rename conflict resolution
• When Drop and recreate is selected, note that all existing data will be lost:

  

  Table Settings step — drop and recreate conflict resolution

Per-Table Storage Configuration

Expand any table row to configure GridGain-specific storage parameters for that table. These parameters map to the options of the GridGain 8 CREATE TABLE command.

Table Settings step — expanded table row

Parameter	Description
Primary key	The column(s) that uniquely identify each record and determine how data is distributed across the cluster.
Cache group	The name of the cache group the underlying cache belongs to. Caches in the same group share internal storage structures to reduce overhead.
Template	The cache template used to create the underlying cache — PARTITIONED or REPLICATED — controlling how data is distributed.
Atomicity	The atomicity mode of the underlying cache: ATOMIC or TRANSACTIONAL. Determines the write mode for the table. If not set, ATOMIC is used.
Data region	The data region in which the table's data is stored.
Affinity key	A column from the primary key used to colocate related rows on the same nodes for faster joins.
Affinity inline size	The inline size, in bytes, for the affinity field index. Leave empty to use the default.
PK inline size	The inline size, in bytes, for the primary key index. Leave empty to use the default.
Key type	The name of the key type for the underlying cache. If not set, a type name is generated automatically.
Value type	The name of the value type for the underlying cache. If not set, a type name is generated automatically.
Write synchronization mode	The write synchronization mode for the underlying cache: FULL_SYNC, FULL_ASYNC, or PRIMARY_SYNC.

Tables with configuration issues are highlighted. The Summary panel on the right shows the total number of fields with problems. Resolve all required issues before proceeding.

You can leave these fields empty to use cluster defaults. This is useful when you want to import the schema quickly and tune storage settings later.

Column Settings

Review and adjust the mapping of source columns to GridGain column definitions.

Column Settings step

Each table can be expanded to inspect its columns. For each column, the wizard shows the source name and type and lets you review and adjust the GridGain 8 mapping:

Field	Description
Name	The source column name. This field is read-only.
Original type	The column's data type in the source database — for example, VARCHAR, LONGVARCHAR, BIGINT, or TIMESTAMP. This field is read-only.
Type	The target GridGain 8 SQL data type for the column. Control Center maps source types to GridGain types automatically using default rules. Types that cannot be mapped automatically are highlighted in red and must be set manually before proceeding.
Nullable	Whether the column accepts NULL values (YES or NO).
Default value type	The default value applied to the column: No value or NULL.
Length / Precision (optional)	The length for character types or the precision for numeric and temporal types. Leave empty to use the type default shown below the field (for example, Default: 65536 for VARCHAR or Default: 6 for TIMESTAMP).

Columns with unmapped or incompatible types are highlighted in red and require manual resolution before you can advance to the next step.

Column Settings step — column type error

Each table can also be expanded to review its indexes. For each index you can configure:

• Name — the name of the index.

• Columns — the columns included in the index.

• Inline size — the optional index inline size, in bytes.

• Parallel — the optional level of parallelism used to build the index.

For each column in the index, set:

• Column — the indexed column.

• Direction — the sort order, ASC or DESC.

Reorder the index columns by dragging them using the handle on the left.

Column Settings step — index

Data Import

This step is shown when Import data after schema is created is enabled on the Connection step. When the toggle is on, COPY statements are generated and included in the script alongside the DDL for execution in the final step.

Configure the data import parameters for each table:

• Select the Import from format: CSV, Parquet, or Apache Iceberg. When Apache Iceberg is selected, only REST and Glue catalog types are supported.

• Then select the Source type: choose File for a local or mounted path. Choose AWS S3 for a cloud bucket and make sure your warehouse path and credentials are configured.

• Set the Source path: enter the full path to your file. For S3, use the warehouse path format (e.g. s3://bucket/path/).

  An incorrect path will result in an empty import with no error.

• Select the target table.

• Select columns to import.

Data Import step — source/target

You can also configure additional parameters if your files use non-standard formatting — such as a custom delimiter, a non-default quote character, or custom null values.

Data Import step — additional params

Script Overview

This tab displays the generated scripts to review and edit before execution.

Overview

From this step you can:

• Copy the script to the clipboard.

• Download the script as an .sql file for use in future deployments or manual execution.

• Open the script in SQL Notebook: Control Center redirects you to the Queries screen, where this script will be available for editing. After you execute the script, the corresponding tables will be created or updated.

You can track execution progress and results in the Queries log tab. If an error occurs, it will also appear there with detailed logs.

Managing Imported Schemas

To view and manage all saved import configurations, choose the Import Schemas menu option in the user profile menu.

Import Schemas menu option

The screen lists all saved configurations with their name, connection type, dialect, target cluster, and last run date. You can filter the list by name, connection type, dialect, and cluster.

Import Schemas screen

For each configuration, the row-level context menu provides the following actions:

• Edit — reopen the configuration to modify it.

• Rename — rename the configuration.

• Open in SQL Notebook — open the generated script in the Queries screen for review or manual execution.

• Remove — delete the configuration.

To view the generated script and connection details for a configuration, click on a schema name to open the side panel on the right.

You can also start a new import from this screen by using the Import schema or Import data buttons in the top-right corner of the screen.