Notes on memory / storage
In SQL Server basic Unit of Storage is page & size is 8 KB.
1 KB= 1024 Bytes
8 * 1024 = 8192 Bytes.
1 Bit =0 0r 1
1 Nibble = 4 Bit
1 Byte= 8 bit
8 KB= 8192 Bytes = 1 SQL page
it contains Data + Page Header + Row Offset
8192 Bytes
96 - available for the page header
8060 - available for the Data
36 Bytes Segregation below, 10 - reserved for heap forward-record backpointer
14 - reserved for versioning tag pointing to the version store in tempdb
12 - available for the slot array
8 kb * 8 pages = 1 extent = 64 KB
Extents
Extents are the basic unit in which space is managed, An extent is eight physically contiguous pages, or 64 KB.
uniform - Uniform extents are owned by a single object, eight pages in the extent can only be used by the owning object.
Mixed - Mixed extents are shared by up to eight objects, Each of the eight pages in the extent can be owned by a different object.
64 KB * 16 = 1024 KB = 1 MB
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