utf8mb40900aici

utf8mb40900aici is the compact form of the MySQL collation name utf8mb4_0900_ai_ci. It denotes a Unicode-aware collation for the utf8mb4 character set, using the Unicode Collation Algorithm (UCA) version 9.0.0 with accent-insensitive and case-insensitive comparison rules. This collations family was introduced with MySQL 8.0 to provide more linguistically accurate sorting and searching for multilingual data compared to older MySQL collations.

Key features include its ability to compare and sort Unicode strings by their base characters while ignoring diacritics (accents) and case distinctions. This makes operations like sorting, searching, and indexing more predictable across languages that use accented characters. Because it is based on the utf8mb4 character set, it also supports all Unicode code points, including supplementary characters outside the Basic Multilingual Plane.

Usage in database schemas typically involves specifying the collation at the database, table, column, or connection level. Examples include creating a database with DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci, converting tables or columns to utf8mb4 with the same collation, or setting the connection to use this collation. It is commonly chosen as a default for new schemas in MySQL 8.0 due to its broad multilingual compatibility.

It is important to note that utf8mb4_0900_ai_ci is not language-specific; certain languages benefit from language-specific collations (for example, Turkish-specific rules). For cases requiring language-aware distinctions, alternative collations such as utf8mb4_turkish_ci may be more appropriate.