Add REFRESH and MATERIALIZED keywords

[RamiNoodle733]

Fixes #797

This PR adds support for the REFRESH keyword to enable proper detection of REFRESH MATERIALIZED VIEW queries.

Changes:

• Add REFRESH as a DDL keyword so get_type() returns 'REFRESH' for REFRESH statements
• Add MATERIALIZED keyword for complete support
• Add test case for REFRESH query type detection

Example:

import sqlparse
query = 'REFRESH MATERIALIZED VIEW order_summary;'
parsed = sqlparse.parse(query)[0]
print(parsed.get_type())  # Now returns 'REFRESH' instead of 'UNKNOWN'

[Copilot]

Pull request overview

This PR adds support for the REFRESH keyword to enable proper detection of REFRESH MATERIALIZED VIEW queries, addressing issue #797. The PR correctly identifies REFRESH as a DDL keyword and adds MATERIALIZED as a regular keyword. Additionally, it includes an unrelated documentation fix for a typo in the tar command.

Changes:

• Added REFRESH as a DDL keyword in keywords.py for query type detection
• Added MATERIALIZED keyword to support REFRESH MATERIALIZED VIEW syntax
• Added test case to verify REFRESH query type returns correctly
• Fixed typo in documentation (tar command from cvfz to xvfz)

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
sqlparse/keywords.py	Added REFRESH (DDL) and MATERIALIZED keywords, but both are placed incorrectly alphabetically
tests/test_grouping.py	Added test case for REFRESH keyword detection following existing test patterns
docs/source/intro.rst	Fixed tar command typo from create (cvfz) to extract (xvfz)

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[Copilot]

The REFRESH keyword is placed incorrectly in the alphabetical order. It should come after REFERENCING (line 466) and before REINDEX (line 467), not after RESOURCE. Maintaining alphabetical order makes the dictionary easier to navigate and maintain.

[Copilot]

The MATERIALIZED keyword is placed incorrectly in the alphabetical order. It should come before MAXEXTENTS (line 362), not after it. The letter 'T' in MATERIALIZED comes before 'X' in MAXEXTENTS alphabetically. Maintaining alphabetical order makes the dictionary easier to navigate and maintain.