What's new in version 11.70.xC8 of IBM Informix:

Migration
Server changes

Changes to online notes

Installation
Windows

Easier installation of 32-bit programs on Windows 64-bit operating systems

Uninstall Informix programs on Windows by using the Control Panel

Administration
Error handling

New event alarm for network failures
IBM OpenAdmin Tool (OAT) for Informix

Customized help is not available

Find what you need by searching OAT
Back up and restore

Optimize backups for data deduplication

Enhanced support for IBM Tivoli Storage Manager features

ON-Bar activity log timestamps
Configuration

Compare onconfig files (UNIX, Linux)

Control the duration and frequency of connection attempts

Performance
Faster operations

In-place alter operations on serial data types
Dynamic tuning

Dynamic private memory caches for CPU virtual processors

Application development
New syntax for queries

Joins with lateral references
Foreign-key constraints

Temporarily prevent constraint validation

Faster creation of foreign-key constraints
Basic text searching

Enhanced basic text searching
New default

Defining separators for fractional seconds in date-time values

High availability
Connection Manager

Improvements to Connection Manager
Monitoring

View log-staging information on RS secondary servers

Enterprise Replication
Easier setup

Simplified schema changes for replicated tables
Configuration

Control the replication of large objects

Custom checksum function for consistency checking

Security
Connectivity

Transport Layer Security (TLS) versions 1.0, 1.1 and 1.2 enabled by default

ВыбегаллоЧота я эту фишку с LATERAL не понимаю. Нафига она введена, и что дает такого, что нельзя было написать раньше ?

Я так понял, что введено для совместимости со стандартами ISO/ANSI, поскольку уже есть в других БД, точно знаю, есть в Oracle.
Требуется, чтобы сделать join во from-е между двумя derived tables (запрос как таблица).
Пример из доки: