Databases
Relational
sqlite postgres MySQL
innodb storage engine prefetches and caches itself with default 16k record size
https://dev.mysql.com/doc/refman/8.4/en/innodb-locking.html dzfsprefetch disable =1, logbias=throughput, primarycache=metadata, atime=off, xattr=sa, recordsize=16k
innodblog write ahead size =16384, innodbdoublewrite =0, innodbchecksum algorithm =none, innodbflush neighbors =0, innodbuse native aio =0, innodbuse atomic writes =0
increase writes by disabling disk flushing with innodbflush log at trx commit =0 and syncbinlog =0. ZFS disable all explicit disk flushing to any one file system by setting sync=disabled so it flushes every ~5sec
https://enhancedformysql.github.io/The-Art-of-Problem-Solving-in-Software-Engineering_How-to-Make-MySQL-Better/ TiDB
somewhat compatible with MySQL
TiKV for key value storage
distributed db
notes
BTree based DB's are more cache friendly as nodes can have more than 2 children (abseil uses 62 children) unlike Binary Trees
binary tree's (red-black like C++ STL) are better with larger sized nodes (moving pointers) than smaller (moving values)
vitess (mysql compat) is used by planetscale and switched from AST interpreter(like postrgres) to bytecodevm(sqlite)