How Can I Create a Locally Managed SYSTEM Tablespace

How can I create a Locally Managed SYSTEM Tablespace? When you specify the EXTENT MANAGEMENT LOCAL clause in the CREATE DATABASE statement, you cause Oracle to create a locally managed SYSTEM tablespace wherein Oracle determines extent sizes. The COMPATIBLE initialization parameter must be set to 9.2 or higher for this statement to be successful. If you do not specify the EXTENT MANAGEMENT LOCAL clause, the default is to create a dictionary-managed SYSTEM tablespace. Locally managed tablespaces provide better performance and greater ease of management over dictionary-managed tablespaces. A locally managed SYSTEM tablespace is created AUTOALLOCATE by default, meaning that it is system managed with extent sizes determined and controlled by Oracle. You may notice an increase in the initial size of objects created in a locally managed SYSTEM tablespace because of the autoallocate policy. It is not possible to create a locally managed SYSTEM tablespace and specify UNIFORM extent size. When you create your database with a locally managed SYSTEM tablespace, ensure the following conditions are met: There must be a default temporary tablespace, and that tablespace cannot be the SYSTEM tablespace. You must not create rollback segments in dictionary-managed tablespaces. Attempting to create a rollback segment in a dictionary-managed tablespace will fail if the SYSTEM tablespace is locally managed. To meet the first condition, you can specify the DEFAULT TEMPORARY TABLESPACE clause in the CREATE DATABASE statement, or you cannot include the clause and allow Oracle to create the tablespace for you using a default name and in a default location. For fulfilling the second condition, Oracle recommends that instead of using rollback segments to manage the database's undo records, that you use automatic undo management. You can include the UNDO TABLESPACE clause in the CREATE DATABASE statement to create a specific undo tablespace, or if you do not include the clause, Oracle creates a locally managed undo tablespace for you using the default name and in a default location. How Oracle Manages Diagnostic Traces and Statistics? Oracle traces various types of diagnostic and statistical information useful to the users and support groups. 01. For the Database Oracle maintains Alert Log File with an ability to the user to set which events are to be traced and which are not to. To identify critical errors and tracing the errors the user is enabled to define

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Transcript of How Can I Create a Locally Managed SYSTEM Tablespace

How can I create a Locally Managed SYSTEM Tablespace?When you specify the EXTENT MANAGEMENT LOCAL clause in the CREATE DATABASE statement you cause O!acle to c!eate a locally mana"e# S$STEM ta%lespace &he!ein O!acle#ete!mines e'tent si(es) The COM*AT+BLE initiali(ation pa!amete! must %e set to ,)- o! hi"he! fo! this statement to %e successful) +f you #o not specify the EXTENT MANAGEMENT LOCAL clause the #efault is to c!eate a #ictiona!y.mana"e# S$STEM ta%lespace)Locally mana"e# ta%lespaces p!o/i#e %ette! pe!fo!mance an# "!eate! ease of mana"ement o/e! #ictiona!y.mana"e# ta%lespaces) A locally mana"e# S$STEM ta%lespace is c!eate# A0TOALLOCATE %y #efault meanin" that it is system mana"e# &ith e'tent si(es #ete!mine#an# cont!olle# %y O!acle) $ou may notice an inc!ease in the initial si(e of o%1ects c!eate# in a locally mana"e# S$STEM ta%lespace %ecause of the autoallocate policy) +t is not possi%le to c!eate a locally mana"e# S$STEM ta%lespace an# specify 0N+2ORM e'tent si(e)When you c!eate you! #ata%ase &ith a locally mana"e# S$STEM ta%lespace ensu!e the follo&in" con#itions a!e met3The!e must %e a #efault tempo!a!y ta%lespace an# that ta%lespace cannot %e the S$STEM ta%lespace)$ou must not c!eate !oll%ac4 se"ments in #ictiona!y.mana"e# ta%lespaces) Attemptin" to c!eate a !oll%ac4 se"ment in a #ictiona!y.mana"e# ta%lespace &ill fail if the S$STEM ta%lespace is locally mana"e#)To meet the fi!st con#ition you can specify the DE2A0LT TEM*ORAR$ TABLES*ACE clause inthe CREATE DATABASE statement o! you cannot inclu#e the clause an# allo& O!acle to c!eate the ta%lespace fo! you usin" a #efault name an# in a #efault location)2o! fulfillin" the secon# con#ition O!acle !ecommen#s that instea# of usin" !oll%ac4 se"ments to mana"e the #ata%ase5s un#o !eco!#s that you use automatic un#o mana"ement) $ou can inclu#e the 0NDO TABLES*ACE clause in the CREATE DATABASE statement to c!eate a specific un#o ta%lespace o! if you #o not inclu#e the clause O!acle c!eates a locally mana"e# un#o ta%lespace fo! you usin" the #efault name an# in a #efault location)How Oracle Manages Diagnostic Traces and Statistics?O!acle t!aces /a!ious types of #ia"nostic an# statistical info!mation useful to the use!s an# suppo!t "!oups)67) 2o! the Data%ase O!acle maintains Ale!t Lo" 2ile &ith an a%ility to the use! to set &hich e/ents a!e to %e t!ace# an# &hich a!e not to) To i#entify c!itical e!!o!s an# t!acin" the e!!o!sthe use! is ena%le# to #efine #estinations fo! #epositin" the t!ace files %y O!acle) They a!e "ene!ally calle# #ump #estinations)Bac4"!oun# #ump #estination0se! #ump #estinationCo!e #ump #estination6-) Net&o!4 #ia"nostic t!ace files a!e "ene!ate# at the #efault #estinations un#e! ORACLE89OME:net&o!4:lo"Settin" a##itional e/ents to t!ac4 the e!!o!s an# #ia"nose the !easons use! has the a%ility toset e/ents at session system an# #ata%ase le/el) Depen#in" upon the natu!e of the e/ent an# the le/el of t!ace some e/ents can %e set at the session le/el some at system le/el an#some at #ata%ase le/el)The +nitiali(ation *a!amete!s that impact the O!acle t!ace "ene!ation;7< ORACLE8TRACE8COLLECT+ON8S+=EORACLE8TRACE8COLLECT+ON8S+=E specifies ;in %ytes< the ma'imum si(e of the O!acle T!ace collection file ;)#at!#%ms>a#min>utl'plan)sDl )) fo! W+NDOWS platfo!msWhen the plan ta%le is populate# then use this Due!y to fetch the #ata fo!matte#) So thatyou un#e!stan# ho& o!acle is plannin" #ata access pathsselect P f!om ta%le;#%ms8'plan)#isplay