É o mais recente dele, o "Cost Based Oracle: Fundamentals", a home page do livro é http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html. É um livro muito bom, mas muito detalhado, realmente não é de forma alguma um guia de referência rápido, eu estou navegando beeeem lenta por ele....
[]s Chiappa --- Em oracle_br@yahoogrupos.com.br, Welvis Douglas Silva Moreto <[EMAIL PROTECTED]> escreveu > > Chiappa qual o nome do Livro do Jonathan Lewis que > voce está lendo?? > > ha muito obrigado pela ajuda vlw, > > att > > Welvis Douglas > > > --- jlchiappa <[EMAIL PROTECTED]> escreveu: > > > Tá explicado, OCP (e OCA, claro) é uma coisa, e a > > vida real é outra, > > é assim mesmo, ao estudar pra OCP não tem conversa, > > vc tem MESMO que > > decorar & engolir um monte de info que na prática > > real nem sempre é > > verdadeira e recomendável... Sem mais o que, pra > > estudar pra OCP é > > assim mesmo. > > > > []s > > > > Chiappa > > > > --- Em oracle_br@yahoogrupos.com.br, Welvis Douglas > > Silva Moreto > > <[EMAIL PROTECTED]> escreveu > > > > > > Chiappa, segue o trecho que coloquei no emal > > passado > > > do livro que estou lendo, é um livro ficado para > > > certificação OCA 10G, o livro é o > > > > > > Sybex - OCA Oracle 10g Administration I Study > > Guide > > > > > > acho que tem lá no amazom.com > > > > > > Choosing Extent Management > > > You can use tablespaces with either local extent > > > management or the older technique of dictionary > > > extent management. With dictionary extent > > management, > > > the database tracks free and > > > used extents in the data dictionary, changing the > > FET$ > > > and UET$ tables with recursive SQL. With > > > local extent management, the database tracks > > extents > > > through the use of bitmaps, eliminating > > > the recursive SQL. Local extent management is the > > > default if not specified and is generally the > > > preferred technique. > > > With locally managed tablespaces, you have two > > options > > > for how extents are allocated: > > > UNIFORM or AUTOALLOCATE. The UNIFORM option tells > > the > > > database to allocate and deallocate > > > extents in the tablespace with the same unvarying > > size > > > that you can specify or let extents default > > > to 1MB. UNIFORM is the default for temporary > > > tablespaces and cannot be specified for undo > > > tablespaces. To create consistent 100MB extents, > > use > > > the clause EXTENT MANAGEMENT LOCAL > > > UNIFORM SIZE 100M in the CREATE TABLESPACE > > statement. > > > Here is an example: > > > CREATE TABLESPACE hist2004apr > > > DATAFILE '/ORADATA/PROD/HIST2004APR.DBF' SIZE 25G > > > EXTENT MANAGEMENT LOCAL UNIFORM SIZE 100M; > > > AUTOALLOCATE, on the other hand, tells the > > database to > > > vary the size of extents for each segment. > > > For example, on Windows and Linux with 8KB data > > > blocks, each segment starts out with > > > 140 Chapter 3 Database Storage and Schema > > Objects > > > 64KB extents for the first 16 extents, and then > > > extents increase in size to 1MB for the next 63 > > > extents. The size then increases to 8MB for the > > next > > > 120 extents, then 64MB, and so on as the > > > segment grows. This algorithm allows small > > segments to > > > remain small and large segments to > > > grow without gaining too many extents. > > AUTOALLOCATE is > > > best used for a general-purpose mixture > > > of small and large tables. Here is an example of > > > creating a tablespace using AUTOALLOCATE: > > > CREATE TABLESPACE hist2004apr > > > DATAFILE '/ORADATA/PROD/HIST2004APR.DBF' SIZE 25G > > > EXTENT MANAGEMENT LOCAL AUTOALLOCATE; > > > You can convert a tablespace from dictionary > > extent > > > management to local extent management > > > and back with the Oracle-supplied PL/SQL package > > > DBMS_SPACE_ADMIN. The SYSTEM > > > tablespace and any temporary tablespaces, however, > > > cannot be converted from local to the > > > older style dictionary management. > > > > > > Choosing Segment Space Management > > > For tablespaces that have local extent management, > > you > > > can use either manual or automatic segment > > > space management. Manual segment space management > > > exists for backward compatibility > > > and uses free block lists to identify the data > > blocks > > > available for inserts together with the > > > parameters PCT_FREE and PCT_USED, which control > > when a > > > block is made available for inserts. > > > After each INSERT or UPDATE, the database compares > > the > > > remaining free space in that data > > > block with the segment's PCT_FREE setting. If the > > data > > > block has less than PCT_FREE free space > > > (meaning that it is almost full), it is taken off > > the > > > free block list and is no longer available for > > > inserts. The remaining free space is reserved for > > > update operations that may increase the size of > > > rows in that data block. After each UPDATE or > > DELETE, > > > the database compares the used space in > > > that data block with that segment's PCT_USED > > setting. > > > If the data block has less than PCT_USED > > > used space, the data block is deemed empty enough > > for > > > inserts and is placed on the free block list. > > > To specify manual segment space management, use > > the > > > SEGMENT SPACE MANAGEMENT > > > MANUAL clause of the CREATE TABLESPACE statement, > > or > > > simply omit the SEGMENT SPACE > > > MANAGEMENT clause. Although Oracle strongly > > recommends > > > AUTOMATIC segment space management > > > for permanent, locally managed tablespaces, the > > > default behavior of Oracle 10g is MANUAL. > > > Here is a statement that creates a tablespace with > > > manual segment space management: > > > CREATE TABLESPACE hist2004apr > > > DATAFILE '/ORADATA/PROD/HIST2004APR.DBF' SIZE 25G > > > EXTENT MANAGEMENT LOCAL AUTOALLOCATE > > > SEGMENT SPACE MANAGEMENT MANUAL; > > > When automatic segment space management is > > specified, > > > bitmaps are used instead of free lists to > > > identify which data blocks are available for > > inserts. > > > The parameters PCT_FREE and PCT_USED are > > > ignored for segments in tablespaces with automatic > > > segment space management. Automatic segment > > > space management is available only on tablespaces > > > configured for local extent management; it is not > > > available for temporary or system tablespaces. > > > Automatic segment space management performs better > > > and reduces your maintenance tasks, making it the > > > preferred technique. > > > Managing Tablespaces 141 > > > To specify automatic segment space management, use > > the > > > SEGMENT SPACE MANAGEMENT > > > AUTO clause of the CREATE TABLESPACE statement, > > like > > > this: > > > CREATE TABLESPACE hist2004apr > > > DATAFILE '/ORADATA/PROD/HIST2004APR.DBF' SIZE 25G > > > EXTENT MANAGEMENT LOCAL AUTOALLOCATE > > > SEGMENT SPACE MANAGEMENT AUTO; > > > > > > > > > > > > > > > --- jlchiappa <[EMAIL PROTECTED]> escreveu: > > > > > > > Cara, afirmar de cara limpa, SEM nenhuma > > restrição, > > > > que X é melhor, > > > > independente de qual aplicativo se usa, de > > quaisquer > > > > condições, como > > > > dá a entender a citação que vc faz desse tal > > livro, > > > > é no mínimo > > > > arriscado : de curiosodade, que livro é esse ?? > > > > Bom, vamos pingar os Is aí : pro Extent > > Management > > > > é isso mesmo, > > > > pode ser UNIFORM ou AUTO. A opção de UNIFORM > > indica > > > > que os extents > > > > vão ser sempre do mesmo tamanho, PORTANTO vc a > > usará > > > > quando SABER que > > > > esse tamanho é bom e apropriado, e isso > > INDEPENDE em > > > > grande porção > > > > de "tamanho de tabela", ok ? Tranquilamente vc > > PODE > > > > ter uma tabela > > > > pequena, de alguns poucos milhares de registros > > que > > > === message truncated === > > > > > _______________________________________________________ > Yahoo! Acesso Grátis - Internet rápida e grátis. Instale > o discador agora! > http://br.acesso.yahoo.com > -------------------------------------------------------------------------------------------------------------------------- Atenção! As mensagens deste grupo são de acesso público e de inteira responsabilidade de seus remetentes. 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