Class: Traject::HorizonReader

Inherits:

Object

• Object
• Traject::HorizonReader

Defined in:

lib/traject/horizon_reader.rb

Overview

Settings

Connection

horizon.jdbc_url

JDBC connection URL using jtds. Should include username, but not password. See ‘horizon.jdbc_password` setting, kept seperate so we can try to suppress it from logging. Eg: “jdbc:jtds:sybase://horizon.lib.univ.edu:2025/dbname;user=dbuser”

• In command line, you’ll have to use quotes: -s ‘horizon.jdbc_url=jdbc:jtds:sybase://horizon.lib.univ.edu:2025/dbname;user=dbuser’

horizon.jdbc_password

Password to use for JDBC connection. We’ll try to suppress it from being logged.

What to export

Normally exports the entire horizon database, for diagnostic or batch purposes you can export just one bib, or a range of bibs instead.

horizon.first_bib

Greater than equal to this bib number. Can be combined with horizon.last_bib

horizon.last_bib

Less than or equal to this bib number. Can be combined with horizon.first_bib

horizon.only_bib

Only this single bib number.

You can also control whether to export staff-only bibs, copies, and items.

horizon.public_only

Default true. If set to true, only includes bibs that are NOT staff_only, also only include copy/item that are not staff-only if including copy/item.

You can also exclude certain tags:

horizon.exclude_tags

Default nil. A comma-seperated string (so easy to supply on command line)

of tag names to exclude from export. You probably want to at least include the tags
you are using for horizon.item_tag and horizon.copy_tag, to avoid collision
from tags already in record.

Item/Copy Inclusion

The HorizonReader can export MARC with holdings information (horizon items and copies) included in the MARC. Each item or copy record will be represented as one marc field – the tags used are configurable. You can configure how individual columns from item or copy tables map to MARC subfields in that field – and also include columns from other tables joined to item or copy.

horizon.include_holdings

• false, nil, or empty string: Do not include holdings. (DEFAULT)

• all: include copies and items

• items: only include items

• copies: only include copies

• direct: only include copies OR items, but not both; if bib has include copies, otherwise include items if present.

Each item or copy will be one marc field, you can configure what tags these fields will have.

horizon.item_tag

Default “991”.

horizon.copy_tag

Default “937”

Which columns from item or copy tables will be mapped to which subfields in those fields is controlled by hashes in settings, hash from column name (with table prefix) to subfield code. There are defaults, see HorizonReader.default_settings. Example for item_map default:

“horizon.item_map” => {

  "item.call_reconstructed"   => "a",
  "collection.call_type"      => "b",
  "item.copy_reconstructed"   => "c",
  "call_type.processor"       => "f",
  "item.item#"                => "i",
  "item.collection"           => "l",
  "item.location"             => "m",
  "item.notes"                => "n",
  "item.staff_only"           => "q"
}

horizon.item_map

horizon.copy_map

The column-to-subfield maps can include columns from other tables joined in, with a join clause configured in settings too. By default both item and copy join to: collection, and call_type – using some clever SQL to join to call_type on the item/copy fk, OR the associated collection fk if no specific item/copy one is defined.

horizon.item_join_clause

horizon.copy_join_clause

Character Encoding

The HorizonReader can convert from Marc8 to UTF8. By default ‘horizon.source_encoding` is set to “MARC8” and `horizon.destination_encoding` is set to “UTF8”, which will make it do that conversion, as well as set the leader byte for char encoding properly.

Any other configuration of those settings, and no transcoding will take place, HorizonReader is not currently capable of doing any other transcoding. Set or ‘horizon.destination_encoding` to nil if you don’t want any transcoding to happen – you’d only want this for diagnostic purposes, or if your horizon db is already utf8 (is that possible? We don’t know.)

horizon.codepoint_translate

translates from Horizon’s weird <U+nnnn> unicode

codepoint escaping to actual UTF-8 bytes. Defaults to true. Will be ignored
unless horizon.destination_encoding is UTF8 though.

Misc

horizon.batch_size

Batch size to use for fetching item/copy info on each bib. Default 400.

debug_ascii_progress

if true, will output a “<” and a “>” to stderr around every copy/item

subsidiary fetch. See description of this setting in docs/settings.md

jtds.jar_path

Normally we’ll use a distribution of jtds bundled with this gem. But specify a filepath of a directory containing jtds jar(s), and all jars in that dir will be loaded instead of our bundled jtds.

Note: Could probably make this even faster by using a thread pool – the bottleneck is probably processing into MARC, not the database query and streaming. But it’s a bit tricky to refactor for concurrency there. Perhaps pull all the raw row values out and batch them in groups by bib#, then feed those lists to a threadpool. And then we’d just be fighting for CPU time with the threadpool for mapping, not sure if overall throughput increase would happen, would depend on exact environment.

Instance Attribute Summary

• #settings ⇒ Object readonly

  Returns the value of attribute settings.

• #things_to_close ⇒ Object readonly

  Returns the value of attribute things_to_close.

Class Method Summary

• .default_settings ⇒ Object

Instance Method Summary

• #convert_marc8_to_utf8? ⇒ Boolean
• #convert_text!(text, error_handler) ⇒ Object

  Converts from Marc8 to UTF8 if neccesary.

• #each ⇒ Object

  Read rows from horizon database, assemble them into MARC::Record’s, and yield each MARC::Record to caller.

• #enhance_batch!(conn, record_batch) ⇒ Object

  Pass in an array of MARC::Records’, adds fields for copy and item info if so configured.

• #fetch_result_set!(conn) ⇒ Object
• #fix_leader!(leader) ⇒ Object

  Mutate string passed in to fix leader bytes for marc21.

• #get_joined_table(conn, batch, options = {}) ⇒ Object

  Can be used to fetch a batch of subsidiary info from other tables: Used to fetch item or copy information.

• #include_some_holdings? ⇒ Boolean
• #initialize(iostream, settings) ⇒ HorizonReader constructor

  We ignore the iostream even though we get one, we’re gonna read from a Horizon DB!.

• #logger ⇒ Object
• #open_connection! ⇒ Object
• #process_batch(batch) ⇒ Object
• #require_jars! ⇒ Object

  Requires marc4j and jtds, and java_import’s some classes.

Constructor Details

#initialize(iostream, settings) ⇒ HorizonReader

We ignore the iostream even though we get one, we’re gonna read from a Horizon DB!

# File 'lib/traject/horizon_reader.rb', line 133

def initialize(iostream, settings)
  # we ignore the iostream, we're fetching from Horizon db

  @settings = Traject::Indexer::Settings.new( self.class.default_settings).merge(settings)

  require_jars!
end

Instance Attribute Details

#settings ⇒ Object (readonly)

Returns the value of attribute settings.

# File 'lib/traject/horizon_reader.rb', line 128

def settings
  @settings
end

#things_to_close ⇒ Object (readonly)

Returns the value of attribute things_to_close.

# File 'lib/traject/horizon_reader.rb', line 129

def things_to_close
  @things_to_close
end

Class Method Details

.default_settings ⇒ Object

# File 'lib/traject/horizon_reader.rb', line 598

def self.default_settings
  {
    "horizon.batch_size" => 400,

    "horizon.public_only" => true,

    "horizon.source_encoding"      => "MARC8",
    "horizon.destination_encoding" => "UTF8",
    "horizon.codepoint_translate"  => true,

    "horizon.item_tag"          => "991",
    # Crazy isnull() in the call_type join to join to call_type directly on item
    # if specified otherwise calltype on colleciton. Phew!
    "horizon.item_join_clause"  => "LEFT OUTER JOIN collection ON item.collection = collection.collection LEFT OUTER JOIN call_type ON isnull(item.call_type, collection.call_type) = call_type.call_type",
    "horizon.item_map"          => {
      "item.call_reconstructed"   => "a",
      "call_type.processor"       => "f",
      "call_type.call_type"      => "b",
      "item.copy_reconstructed"   => "c",
      "item.staff_only"           => "q",
      "item.item#"                => "i",
      "item.collection"           => "l",
      "item.notes"                => "n",
      "item.location"             => "m"
    },

    "horizon.copy_tag"          => "937",
    # Crazy isnull() in the call_type join to join to call_type directly on item
    # if specified otherwise calltype on colleciton. Phew!
    "horizon.copy_join_clause"  => "LEFT OUTER JOIN collection ON copy.collection = collection.collection LEFT OUTER JOIN call_type ON isnull(copy.call_type, collection.call_type) = call_type.call_type",
    "horizon.copy_map"          => {
      "copy.copy#"           => "8",
      "copy.call"            => "a",
      "copy.copy_number"     => "c",
      "call_type.processor"  => "f",
      "copy.staff_only"      => "q",
      "copy.location"        => "m",
      "copy.collection"      => "l",
      "copy.pac_note"        => "n"
    }
  }
end

Instance Method Details

#convert_marc8_to_utf8? ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/traject/horizon_reader.rb', line 573

def convert_marc8_to_utf8?
  settings['horizon.source_encoding'] == "MARC8" && settings['horizon.destination_encoding'] == "UTF8"
end

#convert_text!(text, error_handler) ⇒ Object

Converts from Marc8 to UTF8 if neccesary. Also replaces horizon <U+nnnn> codes if needed.

# File 'lib/traject/horizon_reader.rb', line 235

def convert_text!(text, error_handler)
  text = AnselToUnicode.new(error_handler, true).convert(text) if convert_marc8_to_utf8?

  # Turn Horizon's weird escaping into UTF8: <U+nnnn> where nnnn is a hex unicode
  # codepoint, turn it UTF8 for that codepoint
  if settings["horizon.codepoint_translate"].to_s == "true" && settings["horizon.destination_encoding"] == "UTF8"
    text.gsub!(/\<U\+([0-9A-F]{4})\>/) do
      [$1.hex].pack("U")
    end
  end

  return text
end

#each ⇒ Object

Read rows from horizon database, assemble them into MARC::Record’s, and yield each MARC::Record to caller.

# File 'lib/traject/horizon_reader.rb', line 251

def each
  # Need to close the connection, teh result_set, AND the result_set.getStatement when
  # we're done.
  connection = open_connection!

  # We're going to need to ask for item/copy info while in the
  # middle of streaming our results. JDBC is happier and more performant
  # if we use a seperate connection for this.
  extra_connection = open_connection! if include_some_holdings?

  # We're going to make our marc records in batches, and only yield
  # them to caller in batches, so we can fetch copy/item info in batches
  # for efficiency.
  batch_size = settings["horizon.batch_size"].to_i
  record_batch = []

  exclude_tags = (settings["horizon.exclude_tags"] || "").split(",")


  rs = self.fetch_result_set!(connection)

  current_bib_id = nil
  record = nil
  record_count = 0

  error_handler = org.marc4j.ErrorHandler.new

  while(rs.next)
    bib_id      = rs.getInt("bib#");

    if bib_id != current_bib_id
      record_count += 1

      if settings["debug_ascii_progress"] &&  (record_count % settings["solrj_writer.batch_size"] == 0)
        $stderr.write ","
      end

      # new record! Put old one on batch queue.
      record_batch << record if record

      # prepare and yield batch?
      if (record_count % batch_size == 0)
        enhance_batch!(extra_connection, record_batch)
        record_batch.each do |r|
          # set current_bib_id for error logging
          current_bib_id = r['001'].value
          yield r
        end
        record_batch.clear
      end

      # And start new record we've encountered.
      error_handler = org.marc4j.ErrorHandler.new
      current_bib_id = bib_id
      record = MARC::Record.new
      record.append MARC::ControlField.new("001", bib_id.to_s)
    end


    tagord      = rs.getInt("tagord");
    tag         = rs.getString("tag")

    # just silently skip it, some weird row in the horizon db, it happens.
    # plus any of our exclude_tags.
    next if tag.nil? || tag == "" || exclude_tags.include?(tag)

    numeric_tag = tag.to_i if tag =~ /\A\d+\Z/

    indicators = rs.getString("indicators")

    # a packed byte array could be in various columns, in order of preference...
    # the xref stuff is joined in from the auth table
    # Have to get it as bytes and then convert it to String to avoid JDBC messing
    # up the encoding marc8 grr
    authtext = rs.getBytes("xref_longtext") || rs.getBytes("xref_text")
    if authtext
      authtext = String.from_java_bytes(authtext)
      authtext.force_encoding("binary")
    end

    text     = rs.getBytes("longtext") || rs.getBytes("text")
    if text
      text = String.from_java_bytes(text)
      text.force_encoding("binary")
    end

    text = Traject::HorizonBibAuthMerge.new(tag, text, authtext).merge!

    next if text.nil? # sometimes there's nothing there, skip it.

    # convert from MARC8 to UTF8 if needed
    text = convert_text!(text, error_handler)

    if numeric_tag && numeric_tag == 0
      record.leader = text
      fix_leader!(record.leader)
    elsif numeric_tag && numeric_tag == 1
      # nothing, we add the 001 ourselves first
    elsif numeric_tag && numeric_tag < 10
      # control field
      record.append MARC::ControlField.new(tag, text )
    else
      # data field
      indicator1 = indicators.slice(0)
      indicator2 = indicators.slice(1)

      data_field = MARC::DataField.new(  tag,  indicator1, indicator2 )
      record.append data_field

      subfields  = text.split("\x1F")

      subfields.each do |subfield|
        next if subfield.empty?

        subfield_code = subfield.slice(0)
        subfield_text = subfield.slice(1, subfield.length)

        data_field.append MARC::Subfield.new(subfield_code, subfield_text)
      end
    end
  end
  # last one
  record_batch << record if record

  # yield last batch
  enhance_batch!(extra_connection, record_batch)
  record_batch.each do |r|
    # reset bib_id for error message logging
    current_bib_id = (f = r['001']) && f.value
    yield r
  end
  record_batch.clear

rescue Exception => e
  logger.fatal "HorizonReader, unexpected exception at bib id:#{current_bib_id}: #{Traject::Util.exception_to_log_message(e)}"
  raise e
ensure
  logger.info("HorizonReader: Closing all JDBC objects...")

  # have to cancel the statement to keep us from waiting on entire
  # result set when exception is raised in the middle of stream.
  statement = rs && rs.getStatement
  if statement
    statement.cancel
    statement.close
  end

  rs.close if rs

  # shouldn't actually need to close the resultset and statement if we cancel, I think.
  connection.close if connection

  extra_connection.close if extra_connection

  logger.info("HorizonReader: Closed JDBC objects")
end

#enhance_batch!(conn, record_batch) ⇒ Object

Pass in an array of MARC::Records’, adds fields for copy and item info if so configured. Returns record_batch so you can chain if you want.

# File 'lib/traject/horizon_reader.rb', line 414

def enhance_batch!(conn, record_batch)
  return record_batch if record_batch.nil? || record_batch.empty?

  copy_info = get_joined_table(
    conn, record_batch,
    :table_name  => "copy",
    :column_map  => settings['horizon.copy_map'],
    :join_clause => settings['horizon.copy_join_clause'],
    :public_only => (settings['horizon.public_only'].to_s == "true")
  ) if %w{all copies direct}.include? settings['horizon.include_holdings'].to_s



  item_info = get_joined_table(
    conn, record_batch,
    :table_name  => "item",
    :column_map  => settings['horizon.item_map'],
    :join_clause => settings['horizon.item_join_clause'],
    :public_only => (settings['horizon.public_only'].to_s == "true")
  ) if %w{all items direct}.include? settings['horizon.include_holdings'].to_s



  if item_info || copy_info
    record_batch.each do |record|
      id = record['001'].value.to_s
      record_copy_info = copy_info && copy_info[id]
      record_item_info = item_info && item_info[id]

      record_copy_info.each do |copy_row|
        field = MARC::DataField.new( settings["horizon.copy_tag"] )
        copy_row.each_pair do |subfield, value|
          field.append MARC::Subfield.new(subfield, value)
        end
        record.append field
      end if record_copy_info

      record_item_info.each do |item_row|
        field = MARC::DataField.new( settings["horizon.item_tag"] )
        item_row.each_pair do |subfield, value|
          field.append MARC::Subfield.new(subfield, value)
        end
        record.append field
      end if record_item_info && ((settings['horizon.include_holdings'].to_s != "direct") || record_copy_info.empty?)
    end
  end

  return record_batch
end

#fetch_result_set!(conn) ⇒ Object

# File 'lib/traject/horizon_reader.rb', line 172

def fetch_result_set!(conn)
  #fullbib is a view in Horizon, I think it was an SD default view, that pulls
  #in stuff from multiple tables, including authority tables, to get actual
  # text.
  # You might think need an ORDER BY, but doing so makes it incredibly slow
  # to retrieve results, can't do it. We just count on the view returning
  # the rows properly. (ORDER BY bib#, tagord)
  #
  # We start with the fullbib view defined out of the box in Horizon, but
  # need to join in bib_control to have access to the staff_only column.
  #
  sql = <<-EOS
    SELECT b.bib#, b.tagord, b.tag,
     indicators = substring(b.indicators+'  ',1,2)+a.indicators,
     b.text, b.cat_link_type#, b.cat_link_xref#, b.link_type,
     bl.longtext, xref_text     = a.text, xref_longtext = al.longtext,
     b.timestamp, auth_timestamp = a.timestamp,
     bc.staff_only
    FROM bib b
      left join bib_control bc on b.bib# = bc.bib#
      left join bib_longtext bl on b.bib# = bl.bib# and b.tag = bl.tag and b.tagord = bl.tagord
      left join auth a on b.cat_link_xref# = a.auth# and a.tag like '1[0-9][0-9]'
      left join auth_longtext al on b.cat_link_xref# = al.auth# and al.tag like '1[0-9][0-9]'
    WHERE 1 = 1
  EOS

  sql = <<-EOS
    SELECT b.*, bc.staff_only
    FROM fullbib b
    JOIN bib_control bc on b.bib# = bc.bib#
    WHERE 1 = 1
  EOS

  if settings["horizon.public_only"].to_s == "true"
    sql += " AND staff_only != 1"
  end

  # settings should not be coming from untrusted user input not going
  # to bother worrying about sql injection.
  if settings.has_key? "horizon.only_bib"
    sql += " AND b.bib# = #{settings['horizon.only_bib']} "
  elsif settings.has_key?("horizon.first_bib") || settings.has_key?("horizon.last_bib")
    clauses = []
    clauses << " b.bib# >= #{settings['horizon.first_bib']}" if settings['horizon.first_bib']
    clauses << " b.bib# <= #{settings['horizon.last_bib']}" if settings['horizon.last_bib']
    sql += " AND " + clauses.join(" AND ") + " "
  end

  pstmt = conn.prepareStatement(sql);

  # this may be what's neccesary to keep the driver from fetching
  # entire result set into memory.
  pstmt.setFetchSize(10000)


  logger.debug("HorizonReader: Executing query: #{sql}")
  rs = pstmt.executeQuery
  logger.debug("HorizonReader: Executed!")
  return rs
end

#fix_leader!(leader) ⇒ Object

Mutate string passed in to fix leader bytes for marc21

# File 'lib/traject/horizon_reader.rb', line 555

def fix_leader!(leader)
  if leader.length < 24
    # pad it to 24 bytes, leader is supposed to be 24 bytes
    leader.replace(  leader.ljust(24, ' ')  )
  end
  # http://www.loc.gov/marc/bibliographic/ecbdldrd.html
  leader[10..11] = '22'
  leader[20..23] = '4500'

  if settings['horizon.destination_encoding'] == "UTF8"
    leader[9] = 'a'
  end
end

#get_joined_table(conn, batch, options = {}) ⇒ Object

Can be used to fetch a batch of subsidiary info from other tables: Used to fetch item or copy information. Can fetch with joins too. Usually called by passing in settings, but a literal call might look something like this for items:

get_joined_table(jdbc_conn, array_of_marc_records,

:table_name => "item",
:column_map => {"item.item#" => "i", "call_type.processor" => "k"},
:join_clause => "JOIN call_type ON item.call_type = call_type.call_type"

)

Returns a hash keyed by bibID, value is an array of hashes of subfield->value, eg:

{‘343434’ => [

 {
   'i' => "012124" # item.item#
   'k' => 'lccn'   # call_type.processor
 }
]

}

Can also pass in a ‘:public_only => true` option, will add on a staff_only != 1 where clause, assumes primary table has a staff_only column.

# File 'lib/traject/horizon_reader.rb', line 487

def get_joined_table(conn, batch, options = {})
  table_name  = options[:table_name]  or raise ArgumentError.new("Need a :table_name option")
  column_map  = options[:column_map]  or raise ArgumentError.new("Need a :column_map option")
  join_clause = options[:join_clause] || ""
  public_only = options[:public_only]


  results = Hash.new {|h, k| h[k] = [] }

  bib_ids_joined = batch.collect do |record|
    record['001'].value.to_s
  end.join(",")

  # We include the column name with prefix as an "AS", so we can fetch it out
  # of the result set later just like that.
  columns_clause = column_map.keys.collect {|c| "#{c} AS '#{c}'"}.join(",")
  sql = <<-EOS
    SELECT bib#, #{columns_clause}
    FROM #{table_name}
    #{join_clause}
    WHERE bib# IN (#{bib_ids_joined})
  EOS

  if public_only
    sql += " AND staff_only != 1"
  end

  $stderr.write "<" if settings["debug_ascii_progress"]

  # It might be higher performance to refactor to re-use the same prepared statement
  # for each item/copy fetch... but appears to be no great way to do that in JDBC3
  # where you need to parameterize "IN" values. JDBC4 has got it, but jTDS is just JDBC3.
  pstmt = conn.prepareStatement(sql);
  rs = pstmt.executeQuery


  while (rs.next)
    bib_id = rs.getString("bib#")
    row_hash = {}

    column_map.each_pair do |column, subfield|
      value = rs.getString( column )

      if value
        # Okay, total hack to deal with the fact that holding notes
        # seem to be in UTF8 even though records are in MARC... which
        # ends up causing problems for exporting as marc8, which is
        # handled kind of not very well anyway.
        # I don't even totally understand what I'm doing, after 6 hours working on it,
        # sorry, just a hack.
        value.force_encoding("BINARY") unless  settings["horizon.destination_encoding"] == "UTF8"

        row_hash[subfield] = value
      end
    end

    results[bib_id] << row_hash
  end

  return results
ensure
  pstmt.cancel if pstmt
  pstmt.close if pstmt
  rs.close if rs
  $stderr.write ">" if settings["debug_ascii_progress"]
end

#include_some_holdings? ⇒ Boolean

Returns:

• (Boolean)

# File 'lib/traject/horizon_reader.rb', line 569

def include_some_holdings?
  ! [false, nil, ""].include?(settings['horizon.include_holdings'])
end

#logger ⇒ Object

# File 'lib/traject/horizon_reader.rb', line 594

def logger
  settings["logger"] || Yell::Logger.new(STDERR, :level => "gt.fatal") # null logger
end

#open_connection! ⇒ Object

# File 'lib/traject/horizon_reader.rb', line 578

def open_connection!
  logger.debug("HorizonReader: Opening JDBC Connection at #{settings["horizon.jdbc_url"]} ...")

  url = settings["horizon.jdbc_url"]
  if settings["horizon.jdbc_password"]
    url += ";password=#{settings['horizon.jdbc_password']}"
  end

  conn =  java.sql.DriverManager.getConnection( url )
  # If autocommit on, fetchSize later has no effect, and JDBC slurps
  # the whole result set into memory, which we can not handle.
  conn.setAutoCommit false
  logger.debug("HorizonReader: Opened JDBC Connection.")
  return conn
end

#process_batch(batch) ⇒ Object

# File 'lib/traject/horizon_reader.rb', line 408

def process_batch(batch)

end

#require_jars! ⇒ Object

Requires marc4j and jtds, and java_import’s some classes.

# File 'lib/traject/horizon_reader.rb', line 142

def require_jars!
    Traject::Util.jruby_ensure_init!("Traject::HorizonReader")

    Traject::Util.require_marc4j_jars(settings)

    # For some reason we seem to need to java_import it, and use
    # a string like this. can't just refer to it by full
    # qualified name, not sure why, but this seems to work.
    java_import "org.marc4j.converter.impl.AnselToUnicode"

    unless defined? Java::net.sourceforge.jtds.jdbc.Driver
      jtds_jar_dir = settings["jtds.jar_path"] || File.expand_path("../../vendor/jtds", File.dirname(__FILE__))

      Dir.glob("#{jtds_jar_dir}/*.jar") do |x|
        require x
      end

      # For confusing reasons, in normal Java need to
      # Class.forName("net.sourceforge.jtds.jdbc.Driver")
      # to get the jtds driver to actually be recognized by JDBC.
      #
      # In Jruby, Class.forName doesn't work, but this seems
      # to do the same thing:
      Java::net.sourceforge.jtds.jdbc.Driver
    end

    # So we can refer to these classes as just ResultSet, etc.
    java_import java.sql.ResultSet, java.sql.PreparedStatement, java.sql.Driver
end