19c数据库优化参数
```
alter system set db_file_multiblock_read_count=32 scope=spfile sid='*';
alter system set max_dump_file_size = '500M' scope=spfile sid='*';
alter system set "_memory_imm_mode_without_autosga"=FALSE scope=spfile sid='*';
alter system set job_queue_processes=100 scope=spfile sid='*';
alter system set DB_FILES=4096 scope=spfile sid='*';
alter system set nls_date_format='YYYY-MM-DD HH24:MI:SS' scope=spfile sid='*';
alter system set open_cursors=1000 scope=spfile sid='*';
alter system set open_links_per_instance=48 scope=spfile sid='*';
alter system set open_links=100 scope=spfile sid='*';
alter system set parallel_max_servers=cpu_count*10 scope=spfile sid='*';
alter system set session_cached_cursors=100 scope=spfile sid='*';
alter system set undo_retention=10800 scope=spfile sid='*';
alter system set "_undo_autotune"=false scope=spfile sid='*';
alter system set "_partition_large_extents"=false scope=spfile sid='*';
alter system set "_use_adaptive_log_file_sync"=false scope=spfile sid='*';
alter system set "_optimizer_use_feedback"=false scope=spfile sid='*';
alter system set deferred_segment_creation=false scope=spfile sid='*';
alter system set "_external_scn_logging_threshold_seconds"=600 scope=spfile sid='*';
alter system set "_external_scn_rejection_threshold_hours"=24 scope=spfile sid='*';
alter system set result_cache_max_size=0 scope=spfile sid='*';
alter system set "_cleanup_rollback_entries"=2000 scope=spfile sid='*';
alter system set parallel_force_local=true scope=spfile sid='*'; --rac
alter system set "_gc_policy_time"=0 scope=spfile sid='*';
alter system set "_clusterwide_global_transactions"=false scope=spfile sid='*';
alter system set "_library_cache_advice"=false scope=both sid='*';
alter system set db_cache_advice=off scope=both sid='*';
alter system set filesystemio_options=setall scope=spfile sid='*';
alter system set fast_start_mttr_target=300 scope=spfile sid='*';
alter profile default limit PASSWORD_LIFE_TIME UNLIMITED;
alter profile ORA_STIG_PROFILE limit PASSWORD_LIFE_TIME UNLIMITED;
begin
DBMS_AUTO_TASK_ADMIN.DISABLE(
client_name => 'sql tuning advisor',
operation => NULL,
window_name => NULL);
end;
/
begin
DBMS_AUTO_TASK_ADMIN.DISABLE(
client_name => 'auto space advisor',
operation => NULL,
window_name => NULL);
end;
/
```