r14852@rob-kinyons-computer: rob | 2007-01-18 01:29:59 -0500

 More POD explaining undocumented constructor options

diff --git a/lib/DBM/Deep.pod b/lib/DBM/Deep.pod
index adc2fc7..6d05677 100644 (file)
--- a/lib/DBM/Deep.pod
+++ b/lib/DBM/Deep.pod
@@ -193,6 +193,53 @@ See L</FILTERS> below.
 
 =back
 
+The following parameters may be specified in the constructor the first time the
+datafile is created. However, they will be stored in the header of the file and
+cannot be overridden by subsequent openings of the file - the values will be set
+from the values stored in the datafile's header.
+
+=over 4
+
+=item * num_txns
+
+This is the maximum number of transactions that can be running at one time. The
+default is two - the HEAD and one for imports. The minimum is two and the
+maximum is 255. The more transactions, the larger and quicker the datafile grows.
+
+See L</TRANSACTIONS> below.
+
+=item * max_buckets
+
+This is the number of entries that can be added before a reindexing. The larger
+this number is made, the larger a file gets, but the better performance you will
+have. The default and minimum number this can be is 16. There is no maximum, but
+more than 32 isn't recommended.
+
+=item * pack_size
+
+This is the size of the file pointer used throughout the file. The valid values
+are:
+
+=over 4
+
+=item * small
+
+This uses 2-byte offsets, allowing for a maximum file size of 65K
+
+=item * medium (default)
+
+This uses 4-byte offsets, allowing for a maximum file size of 2G.
+
+=item * large
+
+This uses 8-byte offsets, allowing for a maximum file size of 16XB (exabytes).
+
+=back
+
+See L</LARGEFILE SUPPORT> for more information.
+
+=back
+
 =head1 TIE INTERFACE
 
 With DBM::Deep you can access your databases using Perl's standard hash/array
@@ -843,8 +890,10 @@ a future release.
 =head1 TRANSACTIONS
 
 New in 0.99_01 is ACID transactions. Every DBM::Deep object is completely
-transaction-ready - it is not an option you have to turn on. Three new methods
-have been added to support them. They are:
+transaction-ready - it is not an option you have to turn on. You do have to
+specify how many transactions may run simultaneously (q.v. L</num_txns>).
+
+Three new methods have been added to support them. They are:
 
 =over 4
 
@@ -865,7 +914,7 @@ the transaction.
 =back
 
 Transactions in DBM::Deep are done using the MVCC method, the same method used
-by the InnoDB MySQL table type.
+by the InnoDB MySQL engine.
 
 =head1 PERFORMANCE