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<\/p>\n<\/p>\n
– Cache Layer Data 20 Bytes (Fixed)<\/span><\/p>\n _ Data Block Address<\/span><\/p>\n _ INC : <\/span>\uc18c\uc18d\ub41c Segment <\/span>\uac00 \ubcc0\uacbd\ub420 \ub54c\ub9c8\ub2e4 \uc99d\uac00 (4 bytes)<\/span><\/span><\/p>\n _ SEQ : Block <\/span>\uc5d0 \ub300\ud55c \uc218\uc815\uc774 \ubc1c\uc0dd\ud560 \ub54c\ub9c8\ub2e4 \uc99d\uac00 (4 bytes)<\/span><\/span><\/p>\n _ Data Struct Version<\/span><\/p>\n _ Block Type<\/span><\/p>\n – Transaction Layer 24 Bytes (Fixed) + 23 Bytes (1 ITL Entry) = _ SCN (System Change Number)<\/span><\/p>\n _ Number of ITLs<\/span><\/p>\n _ Flag (\u2018O\u2019: on the free list, \u2018-\u2018:not on the _ Type of Block (1 : Data, 2:Index)<\/span><\/p>\n _ Data Block Address of the next block on the – Transaction Layer Variable Length. 23 * (Number of ITLs \u2013 1)<\/span><\/p>\n _ Transactin ID<\/span><\/p>\n _ undo block address<\/span><\/p>\n _ flag<\/span><\/p>\n _ Number of rows affected by this transaction<\/span><\/p>\n <\/span><\/p>\n – ITL(Interested _ Block<\/span>\uc744 _ INITRANS : Initial number of ITLs when a _ MAXTRNS <\/span><\/p>\n – Data Layer Fixed 14 bytes (Fixed)<\/span><\/p>\n _ block<\/span>\uc758 data area size<\/span><\/span><\/p>\n _ data layer header size<\/span><\/p>\n _ address pointer to the buffer holding the _ flag<\/span><\/p>\n _ number of tables<\/span><\/p>\n _ number of rows in the block<\/span><\/p>\n _ free space size<\/span><\/p>\n – Data Layer Number of tables * 4 + Number of rows * 2 _ location of row <\/span><\/p>\n – Data Block 4 Bytes (Fixed) consists of INC + SEQ<\/span><\/p>\n Row – Row Header _ row<\/span>\uac00 \uc18d\ud55c table<\/span><\/span><\/p>\n _ row directory <\/span>\uc0c1\uc5d0 \ud45c\ud604\ub41c row index<\/span><\/span><\/p>\n _ row size(header + data)<\/span><\/p>\n _ flag<\/span><\/p>\n _ ITL entry or 0 (if the row is not locked)<\/span><\/p>\n <\/span><\/p>\n * Row – Row<\/span>\uae38\uc774\uac00 block size<\/span>\ub97c \ucd08\uacfc\ud558\ub294 \uacbd\uc6b0 \uba87 \uac1c\uc758 block<\/span>\uc5d0 \uac78\uccd0\uc11c chaining<\/span>\ub41c\ub2e4.<\/span><\/span><\/b><\/p>\n – <\/span>\ud55c row<\/span>\uac00 update<\/span>\ub418\ub294\ub370 – Row Chaining <\/span>\uc774 \ubc1c\uc0dd\ud574\ub3c4 \uc6d0\ub798 Row <\/span>\uc758 ROWID<\/span>\uac12\uc740 \ubcc0\ud558\uc9c0 \uc54a\uc74c<\/span><\/b> (ROWID <\/span>\ub294 ROW <\/span>\uc0dd\uc131\ud6c4 \uc0ad\uc81c\uc2dc\uae4c\uc9c0 \ubcc0\ud558\uc9c0 \uc54a\uc74c)<\/span><\/span><\/b><\/p>\n <\/p>\n <\/b><\/span><\/p>\n – Chaining <\/b><\/span>\uc774 \ub9ce\uc774 \ubc1c\uc0dd\ud558\uba74 <\/span>\ub9ce\uc740 block<\/span>\uc744 access<\/span>\ud558\uc5ec\uc57c \ud558\ubbc0\ub85c I\/O performance<\/span>\uac00 \uc800\ud558\ub41c\ub2e4<\/b>.<\/b><\/span><\/span><\/p>\n – Cache Layer Data Block Header 20 Bytes (Fixed) _ Data Block Address _ INC : \uc18c\uc18d\ub41c Segment \uac00 \ubcc0\uacbd\ub420 \ub54c\ub9c8\ub2e4 \uc99d\uac00 (4 bytes) _ SEQ : Block \uc5d0 \ub300\ud55c \uc218\uc815\uc774 \ubc1c\uc0dd\ud560 \ub54c\ub9c8\ub2e4 \uc99d\uac00 (4 bytes) _ Data Struct Version _ Block Type – Transaction Layer Data Block Header 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<\/span><\/span><\/p>\n
\nBlock Header<\/b><\/span><\/p>\n
<\/span><\/p>\n
\nData Block Header<\/b><\/span><\/p>\n
\n47 Bytes<\/span><\/p>\n
\nfree list)<\/span><\/p>\n
\nfree list<\/span><\/p>\n
<\/span><\/p>\n
\nITL Entries<\/b><\/span><\/p>\n
\nTransaction List) –<\/b><\/span><\/p>\n
\n\ubcc0\uacbd\ud558\ub294 \ubaa8\ub4e0 Transaction <\/span>\uc740 ITL<\/span>\uc744 \ub9cc\ub4e4\uac8c \ub418\uba70, Block <\/span>\ub9c8\ub2e4 \uae30\ub85d\ub428.<\/span><\/span><\/b><\/p>\n
\nsegment is created<\/b><\/span><\/p>\n
\n: Maximum number of ITLs for a given segment block<\/b><\/span><\/p>\n
\nHeader<\/span><\/p>\n
\nblock<\/span><\/p>\n
\nVariable Header<\/span><\/p>\n
\n(Table Directory, Row Dicrectory)<\/span><\/p>\n
\nTrailer (End of Block 4 bytes)<\/span><\/p>\n<\/p>\n
<\/span><\/p>\n
<\/span><\/p>\n
\nStructure in a Block<\/span><\/b><\/span><\/p>\n
<\/span><\/b><\/span><\/p>\n
<\/b><\/span><\/p>\n![](\"https:\/\/i0.wp.com\/oracledba.zapto.org\/wordpress\/wp-content\/uploads\/1\/cfile25.uf.231C8C5055E7C6FD35E7A1.jpg?resize=421%2C369\")
<\/p>\n
<\/span><\/b><\/span><\/p>\n
\nInformation<\/span><\/p>\n
<\/span><\/p>\n
\nChaining<\/span><\/b><\/span><\/p>\n
\n\ud544\uc694\ud55c free space<\/span>\uac00 \ubd80\uc871\ud558\uba74 \uadf8 row<\/span>\ub294 \ub2e4\ub978 block<\/span>\uc73c\ub85c migrate<\/span>\ub41c\ub2e4.<\/span><\/span><\/b><\/p>\n
<\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"