Init parameter in 12c database

Database Initialization Parameters for Oracle E-Business Suite Release 12 (Doc ID 396009.1) has recommendations on parameter values.  Below lists init parameters that are not set as the default to support a R12.1.3 instance with about 300 users at peak time.

NAME	VALUE
_b_tree_bitmap_plans	FALSE
_fast_full_scan_enabled	FALSE
_like_with_bind_as_equality	TRUE
_optimizer_autostats_job	FALSE
_sort_elimination_cost_ratio	5
_sqlexec_progression_cost	2147483647
_system_trig_enabled	TRUE
_use_single_log_writer	TRUE
aq_tm_processes	4
audit_sys_operations	TRUE
audit_trail	DB (default is NONE)
compatible	12.1.0
control_file_record_keep_time	30
control_files	/path/to1/ctrl01.dbf, /path/to2/ctrl02.dbf, /path/to3/ctrl03.dbf
cursor_sharing	EXACT
db_block_checking	FALSE
db_block_checksum	TRUE
db_block_size	8192
db_cache_size	5368709120 (or, 5G)
db_files	1000
db_name	EBSPROD
diagnostic_dest	/path/to/db_ebsprod/admin/EBSPROD_ebsdb1p
dml_locks	10000
filesystemio_options	setall
java_jit_enabled	FALSE
job_queue_processes	20
local_listener	(DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EBSPROD_ipc)))
log_archive_dest	/path/to/EBSPROD/arch/arch.log
log_buffer	10485760 (or, 10M)
log_checkpoint_interval	100000
log_checkpoint_timeout	1200
log_checkpoints_to_alert	TRUE
max_dump_file_size	10000
memory_max_target	25769803776 (or, 24G)
memory_target	25769803776
nls_comp	binary
nls_date_format	DD-MON-RR
nls_language	AMERICAN
nls_length_semantics	BYTE
nls_numeric_characters	.,
nls_sort	binary
nls_territory	AMERICA
olap_page_pool_size	4194304 (or, 4M)
open_cursors	4096
optimizer_adaptive_features	FALSE
optimizer_secure_view_merging	FALSE
os_authent_prefix	ext$
parallel_max_servers	64
parallel_min_servers	0
parallel_servers_target	64
parallel_threads_per_cpu	2
pga_aggregate_limit	0
pga_aggregate_target	0 (this is the default. Could be set to 1G)
plsql_code_type	INTERPRETED
plsql_optimize_level	0
processes	3000
query_rewrite_enabled	true
recovery_parallelism	1
recyclebin	ON
remote_login_passwordfile	NONE
remote_os_authent	FALSE
sec_case_sensitive_logon	FALSE
sec_protocol_error_further_action	drop,3
session_cached_cursors	500
session_max_open_files	100
sessions	4536
sga_max_size	25769803776 (or, 24G)
shared_pool_reserved_size	214748364
shared_pool_size	4294967296 (or, 4G)
sql92_security	TRUE
temp_undo_enabled	TRUE
timed_statistics	TRUE
undo_management	AUTO
undo_retention	43200
undo_tablespace	APPS_UNDO_TBS
utl_file_dir	/path/to/EBSPROD/utl_dir, /usr/tmp
workarea_size_policy	AUTO

The database server is an IBM LPAR configuration. 4 Oracle databases on it share its resources of 6 cores CPUs and 92 GB memory, and it is all virtual.

parallel_max_servers =  Maximum value should be 2 X #of CPUs.
This parameter depends on the number of cores. It uses logical CPUs and 5 cores (4-way SMP).  The SMP threads don’t really replicate a full core.

optimizer_adaptive_features = FALSE
If it is set to true, queries may run OK on a first run, but poorly on subsequent runs. Oracle will try to adapt the plans using cardinality feedback and other features that can be good, but can also cause issues.

parallel_threads_per_cpu = 2
Because the core CPU are 4-way SMP, it shows 4x more CPUs than it really has. If it set to a higher value (say, 16), Oracle will keep overallocating the CPU resources for parallel queries and spinning up too many parallel threads for the memory and CPU that it has.