online learning techniques are related to streaming algorithmswhere you see every data point only once think about incoming twitter datait gets loaded into the algorithmsand then the observation (tweetis discarded because the sheer number of incoming tweets of data might soon overwhelm the hardware online learning algorithms differ from streaming algorithms in that they can see the same observations multiple times truethe online learning algorithms and streaming algorithms can both learn from observations one by one where they differ is that online algorithms are also used on static data source as well as on streaming data source by presenting the data in small batches (as small as single observation)which enables you to go over the data multiple times this isn' the case with streaming algorithmwhere data flows into the system and you need to do the calculations typically immediately they're similar in that they handle only few at time dividing large matrix into many small ones whereas in the previous we barely needed to deal with how exactly the algorithm estimates parametersdiving into this might sometimes help by cutting large data table into small matricesfor instancewe can still do linear regression the logic behind this matrix splitting and how linear regression can be calculated with matrices can be found in the sidebar it suffices to know for now that the python libraries we're about to use will take care of the matrix splittingand linear regression variable weights can be calculated using matrix calculus block matrices and matrix formula of linear regression coefficient estimation certain algorithms can be translated into algorithms that use blocks of matrices instead of full matrices when you partition matrix into block matrixyou divide the full matrix into parts and work with the smaller parts instead of the full matrix in this case you can load smaller matrices into memory and perform calculationsthereby avoiding an out-of-memory error figure shows how you can rewrite matrix addition into submatrices aj, an, an, , , bj, bj, bj + , bj + , aj + , aj + , bn, aj, , bn, , , an, , an, , +ba , bn, bn, figure block matrices can be used to calculate the sum of the matrices and