SDF SQL QUERY SUPPORT

This document outlines SQL query syntax supported by SDF configurations.

Depending on the SDF configuration and query schema used, there are two levels of SQL support:

• Adapter level SQL syntax (both at Standard Data View and native source schemas) - This syntax support level applies to EIQ SuperAdapter, and EIQ TurboAdapter configurations.
• Federation level Standard Data View SQL Syntax - This syntax support level applies to EIQ Federation configuration

Apart from the above, applications connecting to EIQ ConventionalAdapter or to a data source using an 'REGDB' connection have to use the native data source supported SQL dialect (SQL Server, Oracle, PostgreSQL, MySQL, DB2, etc.).

SDF uses a customized version of open source PostgreSQL and has the complete SQL capabilities of PostgreSQL underneath (version 14 and later). However, there are a few restrictions on commands that query users can submit based on the configuration they are connecting to.

SDF client queries are generally limited to querying for reading/retrieving data via SEELCT queries, and INSERT, UPDATE and DELETE operations are restricted except in certain cases.

Adapter level SQL syntax supports the full SEELCT syntax of PostgreSQL v14.

Federation level Standard Data View SQL syntax has certain limitations on PostgreSQL SELECT statement when it comes to query optimization. For Federation queries, query execution plans try to push execution to underlying adapters whenever possible, but in some cases data may be retrieved to federation level and processed there.