Rules and Guidelines for Functions in Pushdown Optimization

• •To push TRUNC(DATE) to Amazon Redshift, you must define the date and format arguments. Otherwise, the agent does not push the function to Amazon Redshift.
• •The aggregator functions for Amazon Redshift accept only one argument, a field set for the aggregator function. The filter condition argument is not honored. In addition, make sure that all fields mapped to the target are listed in the GROUP BY clause.
• •To push TO_CHAR() to Amazon Redshift, you must define the date and format arguments.
• •Do not specify a format for SYSTIMESTAMP() to push the SYSTIMESTAMP to Amazon Redshift. The Amazon Redshift database returns the complete time stamp.
• •To push INSTR() to Amazon Redshift, you must only define string, search_value, and start arguments. Amazon Redshift does not support occurrence and comparison_type arguments.
• •The flag argument is ignored when you push TO_BIGINT and TO_INTEGER to Amazon Redshift.
• •The CaseFlag argument is ignored when you push IN() to Amazon Redshift.
• •If you use the NS format as part of the ADD_TO_DATE() function, the agent does not push the function to Amazon Redshift.
• • If you use any of the following formats as part of the TO_CHAR() and TO_DATE() functions, the agent does not push the function to Amazon Redshift:
• - NS
• - SSSS
• - SSSSS
• - RR
• • To push TRUNC(DATE), GET_DATE_PART(), and DATE_DIFF() to Amazon Redshift, you must use the following formats:
• - D
• - DDD
• - HH24
• - MI
• - MM
• - MS
• - SS
• - US
• - YYYY