SQL & PL/SQL

We just migrated to a new dev environment in Linux REDHAT5, and now the query is very slow, and I used the TOAD to run the query, it took like 700 msecond to finish, however from any server connection, the sql query takes hours to finish.

I checked toad monitor, it said need to increase db_buffer_cache and shared pool too small.

Also three red alert from toad is:
1. Library Cache get hit ratio: Dynamic or unsharable sql
2. Chained fetch ratio: PCT free too low for a table
3. parse to execute ratio: HIgh parse to execute ratio.

App team said it ran real quick in the old AIX system, however I ran it in old system, and monitored in the toad, it gave me all same 5 red alerts in old system, and it did provide query results a lot quicker though.

Here is the parameters in the old system (11gr1 on AIX):
SQL> show parameter target

NAME TYPE VALUE
-------------------------------- archive_lag_target integer 0
db_flashback_retention_target integer 1440
fast_start_io_target integer 0
fast_start_mttr_target integer 0
memory_max_target big integer 0
memory_target big integer 0
pga_aggregate_target big integer 278928K
sga_target big integer 0
SQL> show parameter shared

NAME TYPE VALUE
-------------------------------- hi_shared_memory_address integer 0
max_shared_servers integer
shared_memory_address integer 0
shared_pool_reserved_size big integer 31876710
shared_pool_size big integer 608M
shared_server_sessions integer
shared_servers integer 0
SQL> show parameter db_buffer
SQL> show parameter buffer

NAME TYPE VALUE
-------------------------------- buffer_pool_keep string
buffer_pool_recycle string
db_block_buffers integer 0
log_buffer integer 2048000
use_indirect_data_buffers boolean FALSE
SQL>

In new 11gr2 Linux REDHAT parameter:

NAME TYPE VALUE
----------- archive_lag_target integer 0
db_flashback_retention_target integer 1440
fast_start_io_target integer 0
fast_start_mttr_target integer 0
memory_max_target big integer 2512M
memory_target big integer 2512M
parallel_servers_target integer 192
pga_aggregate_target big integer 0
sga_target big integer 1648M
SQL> show parameter shared

NAME TYPE VALUE
----------- hi_shared_memory_address integer 0
max_shared_servers integer
shared_memory_address integer 0
shared_pool_reserved_size big integer 28M
shared_pool_size big integer 0
shared_server_sessions integer
shared_servers integer 1
SQL> show parameter buffer

NAME TYPE VALUE
----------- buffer_pool_keep string
buffer_pool_recycle string
db_block_buffers integer 0
log_buffer integer 18857984
use_indirect_data_buffers boolean FALSE
SQL>

Please help. Thanks in advance.