The Ultimate Guide to Building Efficient Queries for SQL server DBA. PostgreSQL becomes more and mor popular (DB-Engines Ranking)
I will give quick overview about PostgreSQL editions and tuning tools : Open Source, EDB PostgreSQL, Percona PostgreSQL and Azure Database for PostgreSQL Flexible Server and tuning tools and features vs SQL Server from real world experience. Then I will teach you to optimize your queries based on your previous knowledge from SQL Serve as follows:
Optimizing OLTP and OLAP: PostgreSQL Specifics

Algorithm Cost Models
Data Access Algorithms: Full Scan, Index-Based Table Access, Index-Only Scan
B-Tree Indexes and Selection Criteria Other Kinds of Indexes
Combining Relations: Nested Loops, Hash-Based Algorithms, Sort-Merge Algorithm and compration

Understanding Execution Plans
Short Queries and Indexes
What are short queries?
Selection Criteria: Index Selectivity &Unique Indexes and Constraints
Indexes and Non-equal Conditions and Column Transformations
Indexes and the like Operator
Using Multiple Indexes
Compound Indexes
Partial Indexes
Indexes and Join Order
Why Does PostgreSQL Ignore Index?
Let PostgreSQL choose Right Indexes
Build the Right Index(es)

Long Queries and Full Scans
What are long queries?
Full Scans & Hash Joins
Long Queries and the Order of Joins: Semi-joins and Join Order, Anti-join. Semi- and Anti-joins Using the JOIN Operator, When to Specify Join Order
Grouping: Filter First, Group Last & Grouping: Group First, Select Last
Using SET Operations
Avoiding Multiple Scans

More Long Queries Techniques
Temporary Tables and CTEs
Views: Why Use Views?
Creating, using, Refreshing and Optimizing Materialized Views
Partitioning