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4.1 DDL The American National Standards Institute (ANSI) and the International Organization of Standardization (ISO) have jointly established a set of industry standards for the Structured Query Language (SQL). Most relational database management systems (RDBMSs) are either fully compliant or conform to one of the SQL standards. Many features of Informix comply with the SQL-92 Intermediate and Full Level and X/Open SQL Common Applications Environment (CAE) standards. Informix also contains many core features of the SQL99 standard, and many features that are beyond the SQL99 Core are partially or completely supported. However, there are no commands to change the SQL compliance level. SQL Server complies with the entry level of the ANSI SQL-92 standard and with the Federal Information Processing Standards (FIPS 127-2), as established by the US National Institute of Standards and Technology (NIST). You can use the SET FIPS_FLAGGER and SET ANSI_DEFAULTS commands to change the level of compliance and SQL92 behavior. Because both SQL Server and Informix are SQL-92 compliant at a certain level, you can convert many SQL statements and queries written for SQL Server to Informix without modification. However, certain SQL syntax and semantic