Oracle's x$ Tables

select kqftanam from x$kqfta;

x$activeckpt

x$bh

Information on buffer headers.

Contains a record (the buffer header) for each block in the buffer cache.

This select statement lists how many blocks are Available, Free and Being Used.

select count(*), State from (
    select decode (state, 
       0, 'Free',
       1, decode (lrba_seq,
          0, 'Available',
             'Being Used'),
       3, 'Being Used',
          state) State
     from x$bh )
    group by state

The meaning of state:

0	FREE	no valid block image
1	XCUR	a current mode block, exclusive to this instance
2	SCUR	a current mode block, shared with other instances
3	CR	a consistent read (stale) block image
4	READ	buffer is reserved for a block being read from disk
5	MREC	a block in media recovery mode
6	IREC	a block in instance (crash) recovery mode

The meaning of tch: tch is the touch count. A high touch count indicates that the buffer is used often. Therefore, it will probably be at the head of the MRU list. See also touch count.

The meaning of tim: touch time.

class represents a value designated for the use of the block.

set_ds maps to addr on x$kcbwds.

le_addr can be outer joined on x$le.le_addr.

flag is a bit array.

x$bufqm

x$class_stat

x$context

x$globalcontext

x$hofp

x$hs_session

The x$kc... tables

x$kcbbhs

x$kcbmmav

x$kcbsc

x$kcbwait

x$kcbwbpd

Buffer pool descriptor, the base table for v$buffer_pool.

How is the buffer cache split between the default, the recycle and the keep buffer pool.

x$kcbwds

Set descriptor, see also x$kcbwbpd

The column id can be joined with v$buffer_pool.id.

The column bbwait corresponds to the buffer busy waits wait event.

Information on working set buffers

addr can be joined with x$bh.set_ds.

set_id will be between lo_setid and hi_setid in v$buffer_pool for the relevant buffer pool.

x$kccal

x$kccbf

x$kccbi

x$kccbl

x$kccbp

x$kccbs

x$kcccc

x$kcccf

x$kccdc

x$kccdi

x$kccdl

x$kccfc

x$kccfe

x$kccfn

x$kccic

x$kccle

Controlfile logfile entry. Use

select max(lebsz) from x$kccle

to find out the size of a log block. The log block size is the unit for the following init params: log_checkpoint_interval, _log_io_size, and max_dump_file_size.

x$kcclh

x$kccor

x$kcccp

Checkpoint Progress:

The column cpodr_bno displays the current redo block number. Multiplied with the OS Block Size (usually 512), it returns the amount of bytes of redo currently written to the redo logs. Hence, this number is reset at each log switch.

k$kcccp can (together with x$kccle) be used to monitor the progress of the writing of online redo logs. The following query does this.

select
  le.leseq                        "Current log sequence No",
  100*cp.cpodr_bno/le.lesiz       "Percent Full",
  cp.cpodr_bno                    "Current Block No",
  le.lesiz                        "Size of Log in Blocks"
from
  x$kcccp cp,
  x$kccle le
where
  LE.leseq =CP.cpodr_seq
  and bitand(le.leflg,24)=8;

bitand(le.leflg,24)=8 makes sure we get the current log group

How much redo is written by Oracle uses a variation of this SQL statement to track how much redo is written by different DML Statements.

x$kccrs

x$kccrt

x$kccsl

x$kcctf

x$kccts

x$kcfio

x$kcftio

x$kckce

x$kckty

x$kclcrst

x$kcrfx

x$kcrmf

x$kcrmx

x$kcrralg

x$kcrrarch

x$kcrrdest

x$kcrrdstat

x$kcrrms

x$kcvfh

x$kcvfhmrr

x$kcvfhonl

x$kcvfhtmp

x$kdnssf

The x$kg... tables

KG stands for kernel generic

x$kghlu

This view shows one row per shared pool area. If there's a java pool, an additional row is displayed.

x$kgicc

x$kgics

x$kglcursor

x$kgldp

x$kgllk

This table lists all held and requested library object locks for all sessions. It is more complete than v$lock.

The column kglnaobj displays the first 80 characters of the name of the object.

select 
  kglnaobj, kgllkreq
from 
  x$kgllk x join v$session s on 
    s.saddr = x.kgllkses;

kgllkreq = 0 means, the lock is held, while kgllkreq > 0 means that the lock is requested.

x$kglmem

x$kglna

x$kglna1

x$kglob

Library Cache Object

x$kglsim

x$kglst

x$kgskasp

x$kgskcft

x$kgskcp

x$kgskdopp

x$kgskpft

x$kgskpp

x$kgskquep

x$kjbl

x$kjbr

x$kjdrhv

x$kjdrpcmhv

x$kjdrpcmpf

x$kjicvt

x$kjilkft

x$kjirft

x$kjisft

x$kjitrft

x$kksbv

x$kkscs

x$kkssrd

x$klcie

x$klpt

x$kmcqs

x$kmcvc

x$kmmdi

x$kmmrd

x$kmmsg

x$kmmsi

x$knstacr

x$knstasl

x$knstcap

x$knstmvr

x$knstrpp

x$knstrqu

x$kocst

The x$kq... tables

x$kqfco

This table has an entry for each column of the x$tables and can be joined with x$kqfta.

The column kqfcosiz indicates the size (in bytes?) of the columns.

select
  t.kqftanam "Table Name",
  c.kqfconam "Column Name",
  c.kqfcosiz "Column Size"
from
  x$kqfta t,
  x$kqfco c
where
  t.indx = c.kqfcotab

x$kqfdt

x$kqfsz

x$kqfta

It seems that all x$table names can be retrieved with the following query.

select kqftanam from x$kqfta;

This table can be joined with x$kqfco which contains the columns for the tables:

select
  t.kqftanam "Table Name",
  c.kqfconam "Column Name"
from
  x$kqfta t,
  x$kqfco c
where
  t.indx = c.kqfcotab

x$kqfvi

x$kqfvt

x$kqlfxpl

x$kqlset

x$kqrfp

x$kqrfs

x$kqrst

x$krvslv

x$krvslvs

x$krvxsv

The x$ks... tables

KS stands for kernel services.

x$ksbdd

x$ksbdp

x$ksfhdvnt

x$ksfmcompl

x$ksfmelem

x$ksfmextelem

x$ksfmfile

x$ksfmfileext

x$ksfmiost

x$ksfmlib

x$ksfmsubelem

x$ksfqp

x$ksimsi

x$ksled

x$kslei

x$ksles

x$kslld

x$ksllt

x$ksllw

x$kslwsc

x$ksmfs

x$ksmfsv

x$ksmge

x$ksmgop

x$ksmgsc

x$ksmgst

x$ksmgv

x$ksmhp

x$ksmjch

x$ksmjs

x$ksmlru

Memory least recently used

Whenever a select is performed on x$ksmlru, its content is reset!

This table show which memory allocations in the shared pool caused the throw out of the biggest memory chunks since it was last queried.

x$ksmls

x$ksmmem

This 'table' seems to allow to address (that is read (write????)) every byte in the SGA. Since the size of the SGA equals the size of select sum(value) from v$sga, the following query must return 0 (at least on a four byte architecture. Don't know about 8 bytes.)

select 
  (select sum(value)  from v$sga  ) -
  (select 4*count(*) from x$ksmmem) "Must be Zero!"
from 
  dual;

x$ksmsd

x$ksmsp

x$ksmsp_nwex

x$ksmspr

x$ksmss

x$ksolsfts

x$ksolsstat

x$ksppcv

x$ksppcv2

Contains the value kspftctxvl for each parameter found in x$ksppi. Determine if this value is the default value with the column kspftctxdf.

x$ksppi

This table contains a record for all documented and undocumented (starting with an underscore) parameters. select ksppinm from x$ksppi to show the names of all parameters. Join indx+1 with x$ksppcv2.kspftctxpn.

x$ksppo

x$ksppsv

x$ksppsv2

x$kspspfile

x$ksqeq

x$ksqrs

x$ksqst

Enqueue management statistics by type.

ksqstwat: The number of wait for the enqueue statistics class.
ksqstwtim: Cumulated waiting time. This column is selected when v$enqueue_stat.cum_wait_time is selected.

The types of classes are:

x$kstex

x$ksull

x$ksulop

x$ksulv

x$ksumysta

x$ksupr

x$ksuprlat

x$ksurlmt

x$ksusd

Contains a record for all statistics.

x$ksuse

x$ksusecon

x$ksusecst

x$ksusesta

x$ksusgif

x$ksusgsta

x$ksusio

x$ksutm

x$ksuxsinst

x$ktadm

x$targetrba

x$ktcxb

The SGA transaction table.

x$ktfbfe

x$ktfthc

x$ktftme

x$ktprxrs

x$ktprxrt

x$ktrso

x$ktsso

x$ktstfc

x$ktstssd

x$kttvs

Lists save undo for each tablespace: The column kttvstnm is the name of the tablespace that has saved undo. The column is null otherwise.

x$kturd

x$ktuxe

Kernel transaction, undo transaction entry

x$kvis

Has (among others) a row containing the db block size:

 select kvisval from x$kvis where kvistag = 'kcbbkl'

x$kvit

x$kwddef

x$kwqpd

x$kwqps

x$kxfpdp

x$kxfpns

x$kxfpsst

x$kxfpys

x$kxfqsrow

x$kxsbd

x$kxscc

x$kzrtpd

x$kzspr

x$kzsrt

x$le

Lock element: contains an entry for each PCM lock held for the buffer cache. x$le can be left outer joined to x$bh on le_addr.

x$le_stat

x$logmnr_callback

x$logmnr_contents

x$logmnr_dictionary

x$logmnr_logfile

x$logmnr_logs

x$logmnr_parameters

x$logmnr_process

x$logmnr_region

x$logmnr_session

x$logmnr_transaction

x$nls_parameters

x$option

x$prmsltyx

x$qesmmiwt

x$qesmmsga

x$quiesce

x$uganco

x$version

x$xsaggr

x$xsawso

x$xssinfo

A perlscript to find x$ tables

#!/usr/bin/perl -w

use strict;

open O, ("/appl/oracle/product/9.2.0.2/bin/oracle");
open F, (">x");

my $l;
my $p = ' ' x 40;
my %x;

while (read (O,$l,10000)) {
  $l = $p.$l;

  foreach ($l =~ /(x\$\w{3,})/g) {
   $x{$_}++;
  }

  $p = substr ($l,-40);
}

foreach (sort keys %x) {
  print F "$_\n";
}


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