**Use case**
A friend wants to show me a set of queries, but is afraid to reveal the names of columns (domain area) and the values of constants.

**Describe the solution you'd like**
A simple ad-hoc solution that will be mostly acceptable.

Use Lexer to tokenize query and replace tokens. Use a list of english nouns or similar words for replacements. The user will specify a salt in command line to make deterministic pseudorandom unpredictable replacement.

Split identifiers to words according to their style (snake_case, CamelCase, ALL_CAPS). If identifier is too complex, treat it as a single word. These words will be replaced with english nouns selected by the value of a SipHash from the word and the salt. Save all replacements in a map to track collisions. In case of collision, add 1 to the salt and repeat to select another noun. Keep the style of replaced identifiers for convenience. Keep some words like `id`, `num`, `value` unreplaced.

For literals in a query: for numbers, dates, datetimes, apply a model similar to clickhouse-obfuscator. For string literals, keep punctuation charaters as is to keep the meaning of LIKE and regexp. Replace alphanumeric parts to a gibberish of similar length (maybe keeping alpha and numerics). Replace valid UTF-8 to another valid UTF-8 while keeping the number of leading zeros in bytes.

Keep the keywords in the query as is. (Lexer does not know about keywords, so we have to list them explicitly).
{
        String limit_str = toString(suggestion_limit);
        query <<
            " UNION ALL "
            "SELECT name FROM system.databases LIMIT " << limit_str
            << " UNION ALL "
            "SELECT DISTINCT name FROM system.tables LIMIT " << limit_str
            << " UNION ALL "
            "SELECT DISTINCT name FROM system.dictionaries LIMIT " << limit_str
            << " UNION ALL "
            "SELECT DISTINCT name FROM system.columns LIMIT " << limit_str;
    }
    query << ") WHERE notEmpty(res)";
    fetch(connection, timeouts, query.str());
}
void Suggest::fetch(Connection & connection, const ConnectionTimeouts & timeouts, const std::string & query)
{
    connection.sendQuery(timeouts, query);
    while (true)
    {
        Packet packet = connection.receivePacket();
        switch (packet.type)
        {
            case Protocol::Server::Data:
                fillWordsFromBlock(packet.block);
                continue;
            case Protocol::Server::Progress:
                continue;
            case Protocol::Server::ProfileInfo:
                continue;