Implemented PostgreSQL-like ILIKE Operator for ClickHouse

Why it matters

The ILIKE operator solves the problem of performing case-insensitive pattern matching in SQL queries, making it easier and more intuitive for users coming from PostgreSQL or requiring case-insensitive filtering of string data.

How to use it

Use the ILIKE operator in your SQL queries similarly to LIKE but with case-insensitive matching, for example:

SELECT * FROM table WHERE column ILIKE '%pattern%'