Oracle 内核层代码缩写以及释义 - Oracle Kernel Database Layers
KS: Kernel Services
KX: Kernel Execution
K2: Kernel Distributed Transactions
KK: Kernel Compilation
KZ: Kernel Security
KQ: Kernel Query
KA: Kernel Access
KD: Kernel Data
KT: Kernel Transactions
KC: Kernel Cache
KJ: Kernel Locking
KG: Kernel Generic
下面是对这些内核层的简短说明，以便更好地理解 x$ 表与数据库内核之间的关系。 内核服务层为数据库内核堆栈中的所有其他层提供所需的数据库服务。
例如，它为会话和实例级别调节数据库中的初始化参数，以及管理数据库并发操作的锁定、闩锁操作和数据库和实例级别统计的等待事件管理。 接下来要介绍的是内核执行层。
The Kernel Execution layer performs code executions from the Kernel Compilation layer (KK) and handles bind operations for PL/SQL code as well as recursive calls within the shared pool area for the Oracle 11g SGA.
The Kernel Distributed Transaction(K2) layer manages operations involved within distributed transactions including two-phase commit tasks within the Oracle 11g database.
The Kernel Compilation (KK) layer is responsible for managing the compilation of PL/SQL objects along with tasks performed by the Oracle optimizer.
Next is the Kernel Security layer (KZ) which manages role and system privileges within the Oracle 11g database for security operations.
The Kernel Query (KQ) layer handles row caching operations from the data dictionary. It provides critical tasks so that the Kernel Security (KZ) and Kernel Compilation (KK) layers are able to receive data from the query results performed at this Kernel Query layer.
Kernel Access (KA) provides operations that permit access to database segments as well as routing information to other kernel layers within the Oracle 11g database kernel stack.
Kernel Data(KD) manages the storage layer for segments and data retrieval as well as formatting operations of database segments for storage of table data and index data.
Kernel Transactions (KT) manages freelist operations along with rollback segments including interested transaction list (ITL) allocation for operations that occur within data blocks, undo tasks, and transaction consistency based on the ACID model for relational databases.
Kernel Cache (KC) handles operations around the database buffer cache for Oracle 11g. It works hand-in-hand with system functions to manage shared memory resources including the buffer cache and redo log memory operations.
Kernel Locking (KJ) provides for lock management for RAC environments. It does not manage single instance non-RAC lock operations.
The Kernel Generic layer performs basic database kernel operations.
Following is a brief summary of the different kernel services available for review via the x$ tables. First to be examined are the x$ tables around the Kernel Services (KS) layer for Oracle 11g.
Oracle 12c 的信息说明：Here is a list of the "important" x$ tables in Oracle 12c:
|
x$activeckpt |
active checkpoint |
|
x$bh |
buffer header |
|
x$ckptbuf |
checkpoint buffer (queue) |
|
x$dbgalertext |
debug alert extented |
|
x$dbglogext |
debug log extended |
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x$dbgricx, x$dbgrifx, x$dbgrikx, x$dbgripx |
debug tables |
|
x$dbkece |
debug kernel error, critical error |
|
x$dbkefefc |
debug kernel error, fatal error flood control |
|
x$dglparam |
data guard logical parameters |
|
x$diag_alert_ext |
diagnostics alert extended |
|
x$diag_hm_run, x$diag_vhm_run |
diagnostics health monitor runs |
|
x$diag_ips_configuration |
diagnostics incident packaging service configuration |
|
x$dnfs_meta |
dNFS metadata |
|
x$dra_failure |
data recovery advisor failures |
|
x$drm_history, x$drm_history_stats |
dynamic remastering history, stats |
|
x$jskjobq |
job scheduling ?, job queue |
|
x$k2gte, |
kernel 2-phase commit, global transaction entry |
|
x$kbrpstat |
kernel backup recovery process(?) statistics |
|
x$kcbbes |
kernel cache, buffer ? |
|
x$kcbbf |
kernel cache, buffer buffer_handles |
|
x$kcbfwait |
kernel cache, buffer file wait |
|
x$kcbkpfs |
kernel cache, buffer ckpt prefetch statistics |
|
x$kcbkwrl |
kernel cache, buffer write list |
|
x$kcbldrhist |
kernel cache, buffer load direct read history |
|
x$kcbobh |
kernel cache, buffer, objectqueue buffer header |
|
x$kcboqh |
kernel cache, buffer, object queue header |
|
x$kcbsw |
kernel cache, buffer statistics why |
|
x$kcbuwhy |
kernel cache, buffer why |
|
x$kcbwbpd |
kernel cache, buffer workingset buffer pool descriptor |
|
x$kcbwds |
kernel cache, buffer workingset descriptors |
|
x$kcbwh |
kernel cache, buffer where/why |
|
x$kcccf |
kernel cache, controlfilemanagement control file |
|
x$kcccp |
kernel cache, controlfile checkpoint progress |
|
x$kccdi |
kernel cache, controlfilemanagement database information |
|
x$kccle |
kernel cache, controlfile logfile entry |
|
x$kccnrs, x$kccrsp |
kernel cache, controlfile non-guaranteed restorepoint; kernel cache, controlfile restore point |
|
x$kcfis* |
kernel cache, file intelligent scan |
|
x$kclcrst |
kernel cache, (RAC) lock, consistent read statistics |
|
x$kclfh |
kernel cache, (RAC) lock file hashtable |
|
x$kclfi |
kernel cache, (RAC) lock file index |
|
x$kclfx |
kernel cache, (RAC) lock (element) freelist statistics |
|
x$kcluh |
kernel cache, (RAC) lock undo header |
|
x$kclui |
kernel cache, (RAC) lock undo index |
|
x$kcmscn |
kernel cache, maximum SCN |
|
x$kcrfstrand |
kernel cache, redo file strand |
|
x$kcrfx |
kernel cache, redo file context |
|
x$kcrrlns |
kernel cache, recovery process LNS |
|
x$kdxst |
kernel data, index status |
|
x$kdxhs |
kernel data, index histogram |
|
x$kewrtb |
kernel server (manageability), workload repository tables |
|
x$kfdat |
kernel file, disk allocation table? |
|
x$kffxp |
kernel file, file extent map |
|
x$kfklib |
kernel file, - library |
|
x$kghlu |
kernel generic, heap LRUs |
|
x$kglcursor |
kernel generic, librarycache cursor |
|
x$kgllk |
kernel generic, librarycache lock |
|
x$kglob |
kernel generic, librarycache object |
|
x$kglpn |
kernel generic, librarycache pin |
|
x$kglrd |
kernel generic, librarycache readonly dependency |
|
x$kglst |
kernel generic, librarycache statistics |
|
x$kgltr |
kernel generic, librarycache translation |
|
x$kgskvft |
kernel generic, service, ?? fixed table |
|
x$kjxm |
kernel RAC cross-instance (?) messaging |
|
x$kjznhangs, x$kjznhangses |
kernel RAC diag node hang session |
|
x$kmgsct |
kernel memory, granule scoreboard ? |
|
x$kmgstfr |
kernel memory, granule - transfer |
|
x$knstmvr |
kernel replication, statistics materialized view refresh |
|
x$kqdpg |
kernel query, dictionary PGA |
|
x$kqfco |
kernel query, fixed table columns |
|
x$kqfdt |
kernel query, fixed derived table |
|
x$kqfp |
kernel query, fixed package |
|
x$kqfsz |
kernel query, fixed size (size of fixed objects in current version of Oracle) |
|
x$kqfta |
kernel query, fixed table |
|
x$kqfvi |
kernel query, fixed view |
|
x$kqlfsqce |
kernel query, librarycache fixedtable sql cursor environment |
|
x$kqrpd |
kernel query, rowcache parent definition |
|
x$kqrsd |
kernel query, rowcache subordinate definition |
|
x$krbmsft |
kernel recovery, - search file ? |
|
x$krcfh, x$krcfde, x$krcfbh, x$krcbit |
kernel recovery, changetracking file, header, descriptor, bitmap header, bitmap block |
|
x$ksbdd |
kernel service, background detached (process) definition |
|
x$ksbsrvdt |
kernel service, background server detached (process) |
|
x$ksbtabact |
kernel service, background - action |
|
x$ksimsi |
kernel service, instance management serial (and) instance (numbers) |
|
x$ksipc_info and x$ksipc_proc_stats |
kernel service IPC info and process stats |
|
x$ksi_reuse_stats |
kernel service, instance, reuse stats |
|
x$ksled, x$kslei, x$ksles |
kernel service, lock, event descriptors, events for instance, events for session |
|
x$kslemap |
kernel service, lock, event map |
|
x$kslhot |
kernel service, lock, hot (blocks) |
|
x$ksllclass |
kernel service, lock,, latch class |
|
x$ksllw |
kernel service, lock, latch where |
|
x$kslpo |
kernel service, latch posting |
|
x$ksmdd |
kernel service, memory segmented (array) definition |
|
x$ksmfs |
kernel service, memory fixed SGA |
|
x$ksmfsv |
kernel service, memory fixed SGA variables |
|
x$ksmhp |
kernel service, memory heap |
|
x$ksmjch, x$ksmjs |
kernel service, memory, java chunks, java (pool) statistics |
|
x$ksmlru |
kernel service, memory LRU |
|
x$ksmls |
kernel service, memory large (pool) statistics |
|
x$ksmmem |
kernel service, memory |
|
x$ksmns |
kernel service, memory numa (pool) statistics |
|
x$ksmpgdst |
kernel service, memory PGA detailed statistics |
|
x$ksmpp |
kernel service, memory pga heap |
|
x$ksmsp |
kernel service, memory sga heap |
|
x$ksmspr |
kernel service, memory shared pool reserved |
|
x$ksmsp_dsnew |
kernel service, memory shared pool, - statistics new |
|
x$ksmsp_nwex |
kernel service, memory shared pool ? |
|
x$ksmss |
kernel service, memory sga statistics |
|
x$ksmsst, x$ksmstrs |
kernel service, memory, sga streams (pool), streams (pool) statistics |
|
x$ksmssinfo |
kernel service, memory sga OS (level) info |
|
x$ksmup |
kernel service, memory uga heap |
|
x$ksolsfts |
kernel service, object level statistics, fts? |
|
x$ksppcv |
kernel service, parameter, current (session) value |
|
x$ksppi |
kernel service, parameter, parameter info |
|
x$ksppsv |
kernel service, parameter, system value |
|
x$kspspfh |
kernel service, parameter spfile header |
|
x$ksrcctx, x$ksrcdes |
kernel service, (intra-instance) broadcast, channel context, channel description |
|
x$ksrchdl |
kernel service, (intra-instance) broadcast, channel ? |
|
x$kstex |
kernel service, trace execution |
|
x$ksulop |
kernel service, user long operation |
|
x$ksulv |
kernel service, user locale value |
|
x$ksupgp, x$ksupgs |
kernel service, user, process group, process group sniped |
|
x$ksupl, x$ksuru |
kernel service, user, process (resource) limit, resource usage |
|
x$ksuprlat |
kernel service, user process latch |
|
x$ksuse |
kernel service, user session |
|
x$ksusecon |
kernel service, user session connection |
|
x$ksusm |
kernel service, user session migration |
|
x$ksuvmstat |
kernel service, user virtual memory statistics |
|
x$kswsastab |
kernel service, workgroup services, service table |
|
x$ksxafa |
kernel service, execution, - file affinity |
|
x$ksxm_dft |
kernel service, execution, modification dml frequency tracking |
|
x$ksxpclient |
kernel service, ipc, client |
|
x$ksxpif |
kernel service, ipc, interface |
|
x$ksxpping |
kernel service, ipc, ping |
|
x$ksxp_stats |
kernel service, ipc, stats |
|
x$ktcn* |
kernel transaction, change notification * |
|
x$ktcxb |
kernel transaction, control, transaction object |
|
x$ktfbfe |
kernel tablespace, file bitmap free extent |
|
x$ktfbhc |
kernel tablespace, file bitmap header control |
|
x$ktfbnstat |
kernel tablespace, file bigfile - stat |
|
x$ktfbue |
kernel tablespace, file bitmap used extent |
|
x$ktifb, x$ktiff, x$ktifp, x$ktifv |
kernel transaction, in-memory flush, ? |
|
x$ktprhist |
kernel transaction, parallel (transaction) recovery history |
|
x$ktsimapool |
kernel transaction, - in-memory pool |
|
x$ktsj* |
kernel transaction, space job(?) |
|
x$ktskstat |
kernel transaction/tablespace, segment shrink statistics |
|
x$ktslchunk |
kernel transaction/tablespace, space LOB chunk |
|
x$ktspstat |
kernel tablespace, space statistics |
|
x$ktsso |
kernel transaction, sort segment |
|
x$ktugd |
kernel transaction, undo global data |
|
x$ktuqqry |
kernel transaction, undo - query |
|
x$kturhist |
kernel transaction, undo recovery history |
|
x$ktusmst |
kernel transaction, undo system managed, statistics |
|
x$ktuxe |
kernel transaction, undo transaction entry |
|
x$kvii, x$kvit |
kernel (performance) view, instance, initialization, transitory (parameters) |
|
x$kwqbpmt |
kernel OLTP queue ? |
|
x$kxdbio_stats, x$kxdcm*, x$kxdrs |
kernel Exadata, block (level) intelligent operations stats, callback for metrics, resilvering |
|
x$kxfbbox |
kernel execution, fast (parallel process) black box |
|
x$kxfpbs |
kernel execution, fast (parallel) process batch size |
|
x$kxfpcds, x$kxfpcms, x$kxfpcst |
kernel execution, fast (parallel) process, coordinator, dequeue stats, message stats, (query) stats |
|
x$kxfpinstload |
kernel execution, fast (parallel) process instance load |
|
x$kxfpsds, x$kxfpsms, x$kxfpsst |
kernel execution, fast (parallel) process, slave, dequeue stats, message stats, (query) stats |
|
x$kxsbd |
kernel execution, SQL bind data |
|
x$kxttstecs, x$kxttstehs, x$kxttsteis, x$kxttstets |
kernel execution, temporary table stats, column stats, histograms, index stats, table stats |
|
x$kywm* |
kernel - workload management |
|
x$kzspr, x$kzsro |
kernel security, session, privilege, role |
|
x$le |
lock element |
|
x$lobsegstat, x$lobstat, x$logstathist |
LOB (segment) stats, history |
|
x$logbuf_readhist |
Log buffer read histogram |
|
x$messages |
(background process) messages |
|
x$modact_length |
(sql) module action length (limit) |
|
x$qesmmiwt |
query execution, sql memory management ? |
|
x$qesmmsga |
query execution, sql memory management ? |
|
x$qksbgses, x$qksbgsys |
query compilation service, bug session or system |
|
x$qksceses, x$qkscesys |
query compilation service, compilation environment, session or system |
|
x$skgxp_connection, x$skgxp_port |
OS kernel generic interface IPC, connections, ports |
|
x$targetrba |
target RBA |
|
x$trace |
trace |
|
x$uganco |
user global area, network connection |
|
x$xplton, x$xpltoo |
explain plan sql trace(?) operation name, option |
|
x$xs_sessions |
? sessions |
|
x$zasa* |
? |
