Storage plugin names to be case insensitive (DFS vs dfs, INFORMATION_SCHEMA vs information_schema).
Workspace (schemas) names to be case insensitive (ROOT vs root, TMP vs tmp). Even if user has two directories /TMP and /tmp, he can create two workspaces but not both with tmp name. For example, tmp vs tmp_u.
Table names case sensitivity are treated per plugin. For example, system plugins (information_schema, sys) table names (views, tables) should be case insensitive. Actually, currently for sys plugin table names are case insensitive, information_schema table names are case sensitive. That needs to be synchronized. For file system plugins table names must be case sensitive, since under table name we imply directory / file name and their case sensitivity depends on file system.
https://drill.apache.org/docs/lexical-structure/ should be updated with relevant information.