Oracle Internals Notes

Cache Layer Block Types

This is a list of the block type numbers found in cache layer block headers.

CodeBlock TypeVersions1Undo header block (limited extents)all, but superseded by type 14 from 8.0 2Undo data blockall3Save undo header block (limited extents)all, but superseded by type 15 from 8.04Save undo data blockall5Data segment header block (limited extents, no freelist groups)all, but superseded by type 16 from 8.06Table/cluster/index segment data blockall7Temporary segment data blockall8Sort key blockall9Sort run blockall10Free list blockall, but superseded by type 22 from 8.011Data file header blockall12Data segment header block (limited extents, with freelist groups)all, but superseded by type 17 from 8.013Compatibility segmentall14Undo header block (unlimited extents)from 7.315Save undo header block (unlimited extents)from 7.316Data segment header block (unlimited extents, no freelist groups)from 7.317Data segment header block (unlimited extents, with freelist groups) from 7.318Extent map blockfrom 7.319Backup set piece headerfrom 8.020Backup set directory blockfrom 8.021Controlfile blockfrom 8.022Free list block with free block countfrom 8.023LOB segment header blockfrom 8.024LOB segment freelist blockfrom 8.025LOB segment space usage index blockfrom 8.026LOB segment space usage bitmap blockfrom 8.027LOB segment chunk data blockfrom 8.028don't know 29LMT space map header blockfrom 8.130LMT space map blockfrom 8.131don't know 32ASSM level 1 bitmap blockfrom 9.033ASSM level 2 bitmap blockfrom 9.034ASSM level 3 bitmap blockfrom 9.035ASSM segment header blockfrom 9.036ASSM extent map blockfrom 9.037don't know 38System managed undo header blockfrom 9.0

 

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