| Licensing | Enterprise Edition; Workgroup Edition; Express Edition; Free Developer and Innovator-C editions available with limitations | Completely free and open source under PostgreSQL License with no licensing fees or usage limitations | Provides cost-effective migration by eliminating the need for expensive IBM Informix licenses; reduces migration costs by up to 50% through automation |
| Ownership | Owned by IBM Corporation, while HCL Software manages development and support through a long-term partnership agreement | Open source project maintained by PostgreSQL Global Development Group | Ispirer LLC |
| SQL Language | Uses Informix SQL with extensions to ANSI SQL standard; supports SPL (Stored Procedure Language) | Uses standard SQL with PL/pgSQL procedural language and supports multiple procedural languages including PL/Python, PL/Perl, and PL/Tcl | Automatically converts Informix SQL syntax to PostgreSQL-compatible SQL; converts SPL stored procedures to PL/pgSQL with 75-95% automation; handles ANSI SQL extensions conversion |
| Data Types | Rich set including BSON, JSON, BIGINT, BIGSERIAL, BYTE, CHAR, DATE, DATETIME, DECIMAL, FLOAT, INTEGER, INTERVAL, MONEY, TEXT, VARCHAR, and specialized types | Extensive data types including NUMERIC, INTEGER variants, native arrays, JSON, JSONB, UUID, geometric types, and custom user-defined types | Provides intelligent data type mapping from Informix to PostgreSQL equivalents; automatically converts BSON/JSON to PostgreSQL JSON/JSONB; handles custom data type conversions with customization rules |
| Indexing Options | B-tree (default), R-tree, functional indexes, forest of trees (FOT) indexes, and DataBlade module indexes for user-defined data | B-tree (default), GIN, GiST, BRIN, SP-GiST indexes; supports partial/conditional indexes and specialized indexing for various data types | Converts and recreates indexes from Informix to PostgreSQL; maps B-tree and R-tree indexes to appropriate PostgreSQL index types; preserves index performance characteristics |