# I am the Watcher. I am your guide through this vast new twtiverse.
#
# Usage:
# https://watcher.sour.is/api/plain/users View list of users and latest twt date.
# https://watcher.sour.is/api/plain/twt View all twts.
# https://watcher.sour.is/api/plain/mentions?uri=:uri View all mentions for uri.
# https://watcher.sour.is/api/plain/conv/:hash View all twts for a conversation subject.
#
# Options:
# uri Filter to show a specific users twts.
# offset Start index for quey.
# limit Count of items to return (going back in time).
#
# twt range = 1 10
# self = https://watcher.sour.is/conv/7yfkzjq
Problem 2: Your SSD-backed database has a usage-pattern that rewards you with a 80% page-cache hit-rate (i.e. 80% of disk reads are served directly out of memory instead of going to the SSD). The median is 50 distinct disk pages for a query to gather its query results (e.g. InnoDB pages in MySQL). What is the expected average query time from your database?
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Share your solution via Twtxt and how you arrived at it and I'll share my solution tomorrow!
#napkin-math
Problem 2: Your SSD-backed database has a usage-pattern that rewards you with a 80% page-cache hit-rate (i.e. 80% of disk reads are served directly out of memory instead of going to the SSD). The median is 50 distinct disk pages for a query to gather its query results (e.g. InnoDB pages in MySQL). What is the expected average query time from your database?
----
Share your solution via Twtxt and how you arrived at it and I'll share my solution tomorrow!
#napkin-math
* Page size 1MB
* Median 50 pages per query
* 80% pages cached
* 200us SSD reads
* 100us Memory reads
* Query time:
* (50x0.80x100)+(50x0.20x200) = 6,000
* 6000us
* 6ms*
* Page size 1MB
* Median 50 pages per query
* 80% pages cached
* 200us SSD reads
* 100us Memory reads
* Query time:
* (50x0.80x100)+(50x0.20x200) = 6,000
* 6000us
* 6ms*
@bender are one of my assumptions off?
@bender are one of my assumptions off?
@bender I reviewed my solution and it's pretty much spot on! 🤣 the order of magnitude performance is anywhere between 1-10ms
@bender I reviewed my solution and it's pretty much spot on! 🤣 the order of magnitude performance is anywhere between 1-10ms