eliminate_ctes raises OptimizeError on Snowflake GENERATOR() without explicit alias

[ricky-ho]

Issue:
eliminate_ctes raises OptimizeError: Alias already used: (with an empty-string alias) when the SQL contains a Snowflake GENERATOR() table function without an explicit alias (e.g., SELECT 1 FROM TABLE(GENERATOR(10))).

This seemed to be working in a previous version 28.5.0 but when I upgraded to 28.10.1, the error started happening.

Fully reproducible code snippet

import sqlglot
from sqlglot.optimizer import eliminate_ctes

sql = "SELECT 1 FROM TABLE(GENERATOR(10))"
parsed = sqlglot.parse_one(sql, read="snowflake")
eliminate_ctes.eliminate_ctes(parsed)
# sqlglot.errors.OptimizeError: Alias already used: 

sql = "SELECT 1 FROM GENERATOR(10)"
parsed = sqlglot.parse_one(sql, read="snowflake")
eliminate_ctes.eliminate_ctes(parsed)
# sqlglot.errors.OptimizeError: Alias already used: 

[georgesittas]

Optimizer rules shouldn't be used on their own, there are implicit dependencies between them.

This works if you use the full optimize:

>>> from sqlglot.optimizer import optimize
>>> optimize("SELECT 1 FROM TABLE(GENERATOR(10))", dialect="snowflake").sql("snowflake")
...
'SELECT 1 AS "1" FROM TABLE(GENERATOR(ROWCOUNT => 10)) AS "_0"'