Souloist

Keybase proof

I hereby claim:

• I am souloist on github.
• I am souloist (https://keybase.io/souloist) on keybase.
• I have a public key ASB332VIgKQnhCRSm7vTwIzmXzGlxwJfizbmMB50e8e1WQo

To claim this, I am signing this object:

Souloist

Query Optimization

• When optimizing query performance; the EXPLAIN and EXPLAIN ANALYZE commands are used to display how the postgres query planner decided to run a given query.

• The query planner resolves a query by building a tree structure of plan nodes for each step involved in determining the optimal way of fetching data from the database.

• EXPLAIN will not actually run the given query. It will only display the cost estimates that the planner uses for each node.

• EXPLAIN ANALYZE will display the cost estimates as well as actual time in milliseconds for each node.

• The query planner's output should be read inside-out, (bottom to top) to determine the order of the query plan.

• Sample EXPLAIN ANALYZE output:

 Sort  (cost=49150.97..49150.98 rows=2 width=29) (actual time=196.216..196.219 rows=85 loops=1)

Souloist

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.