Update explain code in mysql (only removes deprecation warnings

lib/arjdbc/mysql/adapter.rb

@@ -97,15 +97,27 @@ def write_query?(sql) # :nodoc:
  !READ_QUERY.match?(sql)
  end
 
- def explain(arel, binds = [])
- sql = "EXPLAIN #{to_sql(arel, binds)}"
- start = Concurrent.monotonic_time
- result = exec_query(sql, "EXPLAIN", binds)
- elapsed = Concurrent.monotonic_time - start
+ def explain(arel, binds = [], options = [])
+ sql = build_explain_clause(options) + " " + to_sql(arel, binds)
+ start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+ result = internal_exec_query(sql, "EXPLAIN", binds)
+ elapsed = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
 
  MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
  end
 
+ def build_explain_clause(options = [])
+ return "EXPLAIN" if options.empty?
+
+ explain_clause = "EXPLAIN #{options.join(" ").upcase}"
+
+ if analyze_without_explain? && explain_clause.include?("ANALYZE")
+ explain_clause.sub("EXPLAIN ", "")
+ else
+ explain_clause
+ end
+ end
+
  def each_hash(result) # :nodoc:
  if block_given?
  # FIXME: This is C in mysql2 gem and I just made simplest Ruby
@@ -185,6 +197,11 @@ def discard! # :nodoc:
  #
 
  private
+ # https://mariadb.com/kb/en/analyze-statement/
+ def analyze_without_explain?
+ mariadb? && database_version >= "10.1.0"
+ end
+
  def text_type?(type)
  TYPE_MAP.lookup(type).is_a?(Type::String) || TYPE_MAP.lookup(type).is_a?(Type::Text)
  end