Opening many BDB tables at the same time may be quite slow. If you are going to use BDB tables, you should not have a very large table cache (for example, with a size larger than 256) and you should use the --no-auto-rehash option when you use the mysql client.

SHOW TABLE STATUS does not provide some information for BDB tables:

mysql> SHOW TABLE STATUS LIKE 'bdbtest'\G
*************************** 1. row ***************************
           Name: bdbtest
         Engine: BerkeleyDB
        Version: 10
     Row_format: Dynamic
           Rows: 154
 Avg_row_length: 0
    Data_length: 0
Max_data_length: 0
   Index_length: 0
      Data_free: 0
 Auto_increment: NULL
    Create_time: NULL
    Update_time: NULL
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options:
        Comment:

Optimize performance.

Change to use no page locks for table scanning operations.