What is a log block?
The smallest unit of data storage in SQL Server is a page which is 8 kb in size. SQL Server manages space as Extents, which are made of eight contiguous pages. When it comes to Transaction Log, the fundamental unit of IO is a log block. The size of the log
block is *NOT* fixed and it varies from 512 bytes to 60 kb. Virtual log files known as VLFs are made up of log blocks. And the Transaction Log is made up many VLFs, which are variable in size. For more details on the log block, refer Paul’s post listed
below.
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