GeezerVison

What

Adds support for the SQL Server (T-SQL) OPTION (...) query hint clause at the end of SELECT (including after set operations and FOR XML), UPDATE and DELETE statements, modelled as a new OptionClause holding a list of OptionHints.

Why

The grammar has no production for query hints (#161), so statements like SELECT CustomerID, PersonID, StoreID FROM cte OPTION (MAXRECURSION 2) fail to parse, although this is everyday T-SQL for query tuning.

How

• New OptionClause() production attached in four places (after ForClause in PlainSelect, before LIMIT in the Select wrapper, after LIMIT in Update/Delete), following the Hints (Transact-SQL) - Query Hints documentation.
• OptionHintName() collects (possibly multi-word) keyword names (RECOMPILE, HASH JOIN, OPTIMIZE FOR UNKNOWN, ...) from identifiers, the non-reserved word range and an explicit list of reserved words usable inside hint keywords (JOIN, FOR, ORDER, UNION, EXCEPT, INTERSECT, USE, OPTIMIZE, FORCE, UNKNOWN).
• A hint takes no argument, a single value (FAST 100, MAXDOP 4, MAX_GRANT_PERCENT = 25) or a parenthesized argument list (USE HINT ('...'), OPTIMIZE FOR (@p = 1), TABLE HINT (t, INDEX (i))), kept generically as name + value/parameters because SQL Server keeps adding new hints with every release.
• K_OPTION is a non-reserved keyword; isAliasAhead() treats K_OPTION followed by ( as a clause start rather than a table alias, so option remains usable as a column and table name.
• Like ORDER BY/LIMIT, the clause is hoisted from the last PlainSelect onto the SetOperationList, so SELECT ... UNION SELECT ... ORDER BY ... OPTION (...) deparse in the right order.
• AST classes OptionClause/OptionHint plus wiring in Select, Update, Delete, the three deparsers and the three validators.

Root cause

Missing feature: the grammar has no production for the T-SQL query hint clause, so such statements always threw a ParseException.

Testing

• New OptionClauseTest (13 cases): the issue's SQL plus AST assertions, all hint shapes (keyword / value / equals / parameter list), UNION, FOR XML, UPDATE, DELETE, and option as column/table name; ./gradlew test --tests ...OptionClauseTest passes.
• Full local gate ./gradlew spotlessApply check on the branch: 4816 tests, 0 failures.

Verification of the original issue

Before (master 406a4d4): CCJSqlParserUtil.parse("SELECT CustomerID, PersonID, StoreID FROM cte OPTION (MAXRECURSION 2)") throws a ParseException.
After: parses into PlainSelect with getOption().getOptionHints().get(0) = name MAXRECURSION, value 2, and the deparse round-trips unchanged. All other query hint forms currently documented by Microsoft parse and round-trip as well.

Grammar change, paired gradle jmh runs (JSQLParserBenchmark.parseSQLStatements on performance.sql, version=latest, 10 forks x 10 iterations = 100 samples each, 32-core host), two interleaved pairs:

In both pairs the delta (+0.6%) is smaller than the combined confidence interval -> not statistically significant, no regression.

Limitation: T-SQL also allows OPTION (...) after INSERT and MERGE statements, and the OPTIMIZE FOR (@var UNKNOWN) parameter form; these are not covered yet (the latter needs an AST representation for a variable followed by the bare UNKNOWN keyword, e.g. a dedicated expression type or a nullable-value VariableAssignment; both can be added in follow-ups without changing the modeling introduced here).

Fixes #161