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IBM Db2 for z/OS to Amazon RDS for PostgreSQL conversion settings - Amazon Database Migration Service
Example: Configure IBM Db2 for z/OS to PostgreSQL settings
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IBM Db2 for z/OS to Amazon RDS for PostgreSQL conversion settings

Important

DMS Schema Conversion doesn't provide a Amazon Web Services Management Console experience for the IBM Db2 for z/OS to Amazon RDS for PostgreSQL conversion path. You can't create or configure these migration projects in the Amazon Web Services Management Console, so you configure every setting on this page with the Amazon CLI or the Amazon Database Migration Service API. Because there is no Amazon Web Services Management Console for this conversion path, each setting is identified only by its API and Amazon CLI parameter name, not by a Amazon Web Services Management Console label.

The following settings apply when the source is IBM Db2 for z/OS and the target is Amazon RDS for PostgreSQL or Amazon Aurora PostgreSQL. Configure these settings using the ModifyConversionConfiguration API operation or the Amazon CLI.

This topic covers settings specific to the IBM Db2 for z/OS to PostgreSQL conversion path. In addition to these settings, DMS Schema Conversion provides settings that apply to all source and target pairs, such as the severity level for action-item comments in converted SQL and the option to use generative AI for conversion. For those settings, see Common conversion settings.

When you use the API or Amazon CLI, specify conversion path settings under the section names DB2ZOS_TO_POSTGRESQL, DB2ZOS_TO_POSTGRESQL_14, or DB2ZOS_TO_POSTGRESQL_15. All three versioned sections accept the same keys. To find which section names your project uses, call DescribeConversionConfiguration first and update only the sections present in the response.

Data type and schema settings
ConvertNumberToBigint

Controls how IBM Db2 for z/OS numeric columns without explicit precision are mapped on the target.

  • false — Numeric columns are mapped to PostgreSQL NUMERIC.

  • true — Numeric columns without explicit precision are mapped to PostgreSQL BIGINT. Use this when these columns hold integer values and you want the most efficient integer type.

Type: Boolean (true | false)

Default: false

SchemaNameTemplate

Controls how the target PostgreSQL schema name is generated from the IBM Db2 for z/OS database and schema names.

API/CLI value Generated target schema name
DB_SCHEMA database_schema. Use when migrating multiple databases to the same PostgreSQL instance to avoid name collisions.
DB database
SCHEMA schema. Use when migrating a single database and you want clean schema names without a database prefix.

Type: String (enum)

Default: DB_SCHEMA

Code and constraint settings
GenerateUniqueNamesForConstraints

Controls whether constraint names are made unique across all schemas on the target.

  • true — DMS Schema Conversion appends a hash suffix to each constraint name to guarantee uniqueness across schemas.

  • false — Constraint names are kept as-is, which might cause naming conflicts in multi-schema migrations.

Type: Boolean (true | false)

Default: true

KeepStatementElementsLayout

Controls whether the original whitespace and formatting of SQL statement elements is preserved in the converted output.

  • YES — The original layout is preserved. Converted SQL retains the indentation and line breaks of the source.

  • NO — Statement elements are reformatted using the standard DMS Schema Conversion output style.

Type: String (enum: YES | NO)

Default: YES

DynamicResultSetsToRefcursorsArray

Controls how IBM Db2 for z/OS stored procedures that return dynamic result sets are converted.

  • false — Dynamic result sets are left as action items.

  • true — Dynamic result sets are converted using a PostgreSQL refcursor array, which lets the caller iterate over multiple result sets.

Type: Boolean (true | false)

Default: false

Partition settings
ExcludeTablePartitions

Controls whether table partition definitions are included in the converted DDL.

  • false — Table partition definitions are converted.

  • true — Table partition definitions are excluded from the converted DDL. Use this when your target instance doesn't need partition-level DDL or when you manage partitioning separately.

Type: Boolean (true | false)

Default: false

ParttnedTabPkUnqToSecondaryIdx

Controls how primary key and unique constraints on partitioned tables are converted.

  • false — Primary key and unique constraints are kept as constraints on the target.

  • true — Primary key and unique constraints on partitioned tables are converted to secondary indexes instead of constraints.

Type: Boolean (true | false)

Default: false

Note

Use the exact spelling ParttnedTabPkUnqToSecondaryIdx when you call the API or Amazon CLI.

PartitionCount

The default number of partitions to use when converting partitioned tables.

Type: Integer

Default: 50

PartitionMaxCount

The maximum number of partitions allowed when converting partitioned tables.

Type: Integer

Default: 100

TableSize

The table size threshold, in megabytes, that DMS Schema Conversion uses to determine the partitioning strategy during conversion.

Type: Number (MB)

Default: 100.0

UseEnforcePartition

Controls whether DMS Schema Conversion generates explicit partition enforcement clauses in the converted DDL for partitioned tables.

  • false — Partition enforcement clauses are not generated.

  • true — DMS Schema Conversion generates partition enforcement clauses for tables larger than the TableSize threshold.

Type: Boolean (true | false)

Default: false

UsePartitionsProportionally

Controls whether DMS Schema Conversion scales the number of generated partitions in proportion to table size.

  • false — A fixed number of partitions is used.

  • true — The number of partitions increases proportionally with table size.

Type: Boolean (true | false)

Default: false

Date and time format settings
StringRepresentationOfDate

Controls the string format used when representing IBM Db2 DATE values in converted code.

API/CLI value Format Example
ISO YYYY-MM-DD 2024-01-15
EUR DD.MM.YYYY 15.01.2024
USA MM/DD/YYYY 01/15/2024
JIS YYYY-MM-DD 2024-01-15

Type: String (enum)

Default: ISO

StringRepresentationOfTime

Controls the string format used when representing IBM Db2 TIME values in converted code.

API/CLI value Format Example
ISO HH:MM:SS 14:30:00
EUR HH.MM.SS 14.30.00
USA HH:MM AM/PM 02:30 PM
JIS HH:MM:SS 14:30:00

Type: String (enum)

Default: ISO

Schema tree view settings

The following settings control which schemas and databases appear in the schema tree view. They affect what you can select for conversion; they don't change the converted SQL output.

TreeSettingsHideEmpty

Controls whether schemas that contain no objects appear in the schema tree view.

  • true — Empty schemas are hidden.

  • false — All schemas are shown, including empty ones.

Type: Boolean (true | false)

Default: true

TreeSettingsHideEmptyDb

Controls whether databases that contain no objects appear in the schema tree view.

  • true — Empty databases are hidden.

  • false — All databases are shown, including empty ones.

Type: Boolean (true | false)

Default: true

TreeSettingsSystemSchemas

Controls whether system schemas appear in the schema tree view alongside user schemas.

  • false — Only user schemas are shown.

  • true — System schemas are shown alongside user schemas.

Type: Boolean (true | false)

Default: false

Example: Configure IBM Db2 for z/OS to PostgreSQL settings

The following example sets the partition count and the date format. Apply the same settings to each section name that your project uses (check the output of DescribeConversionConfiguration first).

{
  "DB2ZOS_TO_POSTGRESQL_15": {
    "PartitionCount": 20,
    "StringRepresentationOfDate": "EUR"
  },
  "DB2ZOS_TO_POSTGRESQL_14": {
    "PartitionCount": 20,
    "StringRepresentationOfDate": "EUR"
  },
  "DB2ZOS_TO_POSTGRESQL": {
    "PartitionCount": 20,
    "StringRepresentationOfDate": "EUR"
  }
}