Thinking About Contexts

Ewald Cress has started a new series on system internals:

Per-processor partitioning of certain thread management functions makes perfect sense, since we’d aim to minimise the amount of global state. Thus each processor would have its own dispatcher state, its own timer list… And hang on, this is familiar territory we know from SQLOS! The only difference is that SQLOS operates on the premise of virtualising a CPU in the form of a Scheduler, whereas the OS kernel deals with physical CPUs, or at least what it honestly believes to be physical CPUs even in the face of CPU virtualisation.

This is a start to a very interesting series.

Related Posts

The Bitmap Operator

Hugo Kornelis describes a new operator: The Bitmap operator is used to build a bitmap that, based on a hash, represents which values may be present in a data flow. Due to the chance of hash collisions in the hash function used, the Bitmap process can produce false positives but not false negatives – so a match based on […]

Read More

Visualizing Merge Joins

Bert Wagner continues his series on physical join operators: The base algorithm works as follows: SQL Server compares the first rows from both sorted inputs.  It then continues comparing the next rows from the second input as long as the values match the first input’s value.Once the values no longer match, SQL Server increments the […]

Read More

Categories

February 2017
MTWTFSS
« Jan Mar »
 12345
6789101112
13141516171819
20212223242526
2728