From: Jim Cain <jecain@...>
Date: 2007-04-03T06:08:17+09:00
Subject: Re: Using transactions with secondary indexes in bdb

I've updated my previous example to include transactions:

  BDB::Hash.open('models.db', nil, BDB::CREATE | BDB::TRUNCATE) {}
  BDB::Hash.open('makes.db', nil, BDB::CREATE | BDB::TRUNCATE,
:set_flags => BDB::DUP | BDB::DUPSORT) {}

  env = BDB::Env.new('/home/jim/eclipse/testRuby',
BDB::CREATE|BDB::INIT_TRANSACTION)
  models = env.open_db(BDB::HASH, 'models.db', nil, BDB::CREATE)
  makes = env.open_db(BDB::HASH, 'makes.db', nil, BDB::CREATE,
:set_flags => BDB::DUP | BDB::DUPSORT)

  env.begin(models, makes) do |tx, tx_models, tx_makes|
    tx_models.associate(tx_makes) { |sdb, key, value| value }
    tx.commit
  end

  puts '===== Before'
  puts '----- models'
  models.each { |key, value| puts "#{key} = #{value}" }
  puts '----- makes'
  makes.each_primary { |skey, pkey, pvalue| p [skey, pkey, pvalue] }

  env.begin(BDB::TXN_COMMIT, models, makes) do |tx, tx_models, tx_makes|
    tx_models['Civic'] = 'Honda'
    tx_models['Accord'] = 'Honda'
    tx_models['S2000'] = 'Honda'
    tx_models['Camry'] = 'Toyota'
    tx_models['Solara'] = 'Toyota'
  end

  env.begin(models, makes) do |tx, tx_models, tx_makes|
    puts '===== After'
    puts '----- models'
    tx_models.each { |key, value| puts "#{key} = #{value}" }
    puts '----- makes'
    tx_makes.each_primary { |skey, pkey, pvalue| p [skey, pkey, pvalue] }
  end

  env.begin(BDB::TXN_COMMIT, models, makes) do |tx, tx_models, tx_makes|
    tx_makes.close
    tx_models.close
  end

  env.close

Here is the output:

===== Before
----- models
----- makes
===== After
----- models
Civic = Honda
Accord = Honda
Camry = Toyota
Solara = Toyota
S2000 = Honda
----- makes

It doesn't appear to be updating the secondary index. What have I done wrong?

Cheers,
Jim