OLAP and OLTP \
oltp are the transaction based db systems where you focus on transactions like create , update , read , delete and ensure that a transaction happens atomicity and consistency these are the row oriented db and used for most of the services to handle data , olap on the other hand are focused on the data analysis , these are column oriented
chap 2
data organisation in general , most of the time read is larger than writes
how you write has different performance issue than how you read so we have to look into tradeoffs
on write it takes effort , but on read which is large number of operations that will be easier
binary search trees why not use this for db always
io devices work with pages like 8 kb chunks
b+ trees
each node can fit in a 8,16 kb page on disk
sometimes leaf node can contain the data sometime only the pointer to the location of data
mysql stores data in clustered index ,
row data is stored in leaf
postgres does this differently
l-3