Method parseImpl

src/Parsers/ParserSystemQuery.cpp:244–1071

}

bool ParserSystemQuery::parseImpl(IParser::Pos & pos, ASTPtr & node, Expected & expected)
{
    if (!ParserKeyword{Keyword::SYSTEM}.ignore(pos, expected))
        return false;

    using Type = ASTSystemQuery::Type;

    auto res = make_intrusive<ASTSystemQuery>();

    bool found = false;

    for (const auto & type : magic_enum::enum_values<Type>())
    {
        if (ParserKeyword::createDeprecated(ASTSystemQuery::typeToString(type)).ignore(pos, expected))
        {
            res->type = type;
            found = true;
            break;
        }
    }

    /// SYSTEM DROP [...] CACHE sounds like the statement disables the cache but it merely clears it.
    /// SYSTEM CLEAR [...] CACHE is the preferred syntax but we need to retain support for DROP.
    if (!found)
    {
        static const std::vector<std::pair<std::string_view, Type>> system_aliases = {
            {"DROP DNS CACHE", Type::CLEAR_DNS_CACHE},
            {"DROP CONNECTIONS CACHE", Type::CLEAR_CONNECTIONS_CACHE},
            {"DROP MARK CACHE", Type::CLEAR_MARK_CACHE},
            {"DROP PRIMARY INDEX CACHE", Type::CLEAR_PRIMARY_INDEX_CACHE},
            {"DROP UNCOMPRESSED CACHE", Type::CLEAR_UNCOMPRESSED_CACHE},
            {"DROP INDEX MARK CACHE", Type::CLEAR_INDEX_MARK_CACHE},
            {"DROP INDEX UNCOMPRESSED CACHE", Type::CLEAR_INDEX_UNCOMPRESSED_CACHE},
            {"DROP VECTOR SIMILARITY INDEX CACHE", Type::CLEAR_VECTOR_SIMILARITY_INDEX_CACHE},
            {"DROP TEXT INDEX TOKENS CACHE", Type::CLEAR_TEXT_INDEX_TOKENS_CACHE},
            {"DROP TEXT INDEX HEADER CACHE", Type::CLEAR_TEXT_INDEX_HEADER_CACHE},
            {"DROP TEXT INDEX POSTINGS CACHE", Type::CLEAR_TEXT_INDEX_POSTINGS_CACHE},
            {"DROP TEXT INDEX CACHES", Type::CLEAR_TEXT_INDEX_CACHES},
            {"DROP MMAP CACHE", Type::CLEAR_MMAP_CACHE},
            {"DROP QUERY CONDITION CACHE", Type::CLEAR_QUERY_CONDITION_CACHE},
            {"DROP QUERY CACHE", Type::CLEAR_QUERY_CACHE},
            {"DROP COMPILED EXPRESSION CACHE", Type::CLEAR_COMPILED_EXPRESSION_CACHE},
            {"DROP ICEBERG METADATA CACHE", Type::CLEAR_ICEBERG_METADATA_CACHE},
            {"DROP PARQUET METADATA CACHE", Type::CLEAR_PARQUET_METADATA_CACHE},
            {"DROP FILESYSTEM CACHE", Type::CLEAR_FILESYSTEM_CACHE},
            {"DROP DISTRIBUTED CACHE", Type::CLEAR_DISTRIBUTED_CACHE},
            {"DROP DISK METADATA CACHE", Type::CLEAR_DISK_METADATA_CACHE},
            {"DROP PAGE CACHE", Type::CLEAR_PAGE_CACHE},
            {"DROP SCHEMA CACHE", Type::CLEAR_SCHEMA_CACHE},
            {"DROP FORMAT SCHEMA CACHE", Type::CLEAR_FORMAT_SCHEMA_CACHE},
            {"DROP AVRO SCHEMA CACHE", Type::CLEAR_AVRO_SCHEMA_CACHE},
            {"DROP S3 CLIENT CACHE", Type::CLEAR_S3_CLIENT_CACHE},
        };

        for (const auto & [alias, type] : system_aliases)
        {
            if (ParserKeyword::createDeprecatedPtr(alias)->ignore(pos, expected))
            {