报警日志中的memory项的Ph，PgF都是什么意思

报警日志中的

Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options.
Windows NT Version V6.2  
CPU                 : 32 - type 8664, 32 Physical Cores
Process Affinity    : 0x0x0000000000000000
Memory (Avail/Total): Ph:22813M/49151M, Ph+PgF:437M/196607M 
VM name             : VMWare Version (6)
System parameters with non-default values:
  processes                = 500
  sessions                 = 800
  sga_max_size             = 32G
  _realfree_heap_pagesize_hint= 256K
  _use_realfree_heap       = TRUE
  _kghdsidx_count          = 1
  nls_language             = "SIMPLIFIED CHINESE"
  nls_territory            = "CHINA"
  sga_target               = 18G
  memory_target            = 0
  control_files            = "D:\EAS\EAS\CONTROL01.CTL"
  control_files            = "D:\EAS\FAST_RECOVERY\EAS\CONTROL02.CTL"
  db_block_size            = 8192
  compatible               = "11.2.0.4.0"
  db_recovery_file_dest    = "D:\EAS\fast_recovery"
  db_recovery_file_dest_size= 4182M
  undo_tablespace          = "UNDOTBS1"
  remote_login_passwordfile= "EXCLUSIVE"
  db_domain                = ""
  dispatchers              = "(PROTOCOL=TCP) (SERVICE=EASXDB)"
  audit_file_dest          = "D:\ORACLE\ADMIN\EAS\ADUMP"
  audit_trail              = "DB"
  open_cursors             = 300
  pga_aggregate_target     = 12G
  diagnostic_dest          = "D:\ORACLE"

trace文件中的

*** 2023-04-20 15:14:26.930
ORA-04030: 在尝试分配 485216 字节 (kkoutlCreatePh,ub1 : kkoabr) 时进程内存不足
Trace file D:\ORACLE\diag\rdbms\eas\eas\trace\eas_ora_1900.trc
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Windows NT Version V6.2  
CPU                 : 32 - type 8664, 32 Physical Cores
Process Affinity    : 0x0x0000000000000000
Memory (Avail/Total): Ph:22338M/49151M, Ph+PgF:5M/196607M 
VM name             : VMWare Version (6)
Instance name: eas
Redo thread mounted by this instance: 1
Oracle process number: 28
Windows thread id: 1900, image: ORACLE.EXE (SHAD)

Ph+PgF:5M/196607M

为什么是5m，为什么这么小呢