Faster PostgreSQL: Improved Writes

This paper will mainly talk about the write performance improvements done in PostgreSQL 9.6 and will share the experiments showing the extra WAL data written due to the current algorithm used to write WAL.

This paper will discuss about weakness of current locking strategy for various locks used at Commit-time and new algorithm used to improve the situation along with performance data. I will then talk about the situations where this algorithm can be used at other places in PostgreSQL. It will also describe about the performance improvements being currently worked on like bulk-load and others that are done for 9.6.

It will also discuss about the weakness of current WAL writing algorithm due to which it writes much more amount of WAL than required and some ideas to improve the algorithm which will lead to reduced amount of WAL writes. I will also share the data showing the extra writes and some experiments done by me to reduce the same and the pros and cons of each approach used to reduce the WAL-writes.