Charlotte SQL Saturday 2019, Presentation on migrating to Postgresql

1. Migrating to Postgresql
For Charlotte SQL Saturday on 12/07/2019
By Ramu Pulipati

2. Thank You to our Sponsors

3. About Me
Cofounder / CTO at Botsplash
Software-as-a-service and hosted
messaging platform to engage
businesses and customers. botsplash.com

4. What is Postgresql?
• Free & Open Source RDMS
• Alternative to Microsoft SQL Server, MySQL, Oracle, Mongo
DB or any RDBMS and NoSQL databases
• Battle tested for over 30 years with continuous
improvements to support modern applications

5. DERIVED
Who uses
PostgreSQL?
EXTENSIONS

6. Why Postgresql?
• BSD License
• Free for Commercial use
• No vendor Lock-in
• Predictable releases & fixes
• Active Community
• Great Performance
• Extensibility
• Hosted options
• Professional Services
Source: postgresql.org

7. Differentiators
• Strong SQL Types
• Rich JSON Support / NoSQL
• Native Table Partitioning
• Full Text Search
• Pubsub
• GIS / Spatial Functionality
• Scalability & Multi-tenancy
• Extensibility
80%
Commercial
Databases
Postgresql

8. Trends
Source: Stackoverflow from
Igal Sapir slides

9. Compare with others
• Replaces
• Mongo Db
• SQL Server
• MySQL
• Oracle
• Complements
• Redis
• Elasticsearch
• Clickhouse
Source: NoSQL Performance Benchmark 02/27/2018

10. History & What’s new Version Major Feature
V12
10/03/2019
JSONB Query & Partition
Improvements, Performance
V11
10/18/2018
Query Parallelism Improvements
Just-in-time compilation
V10
10/05/2017
Declarative Table Partitions
Logical Replication
Improved Monitoring and Control
V9.6
09/29/2016
Parallel Query
Foreign Data Wrappers
Replication
V9.5
07/01/2016
JSONB Modifying Operators
Row level security
UPSERT statement
V9.4
12/18/2014
Introduce JSONB
Materialized View Improvements
Source: Postgresql Releases

11. Getting Started
• Download and Install
• Postgres 11+ supports Windows
2012 R2 deployment.
• Cloud hosting options
• Client
• pgAdmin
• psql command line

12. SQL Support
• Case Sensitive Schema Names
• Case Sensitive Data Storage
• Type casting & Operators
• Date Time formatting
• Common Table Expressions
• Array Data Types
• Upserts
• Stored Procedures
• Multiple languages support

13. Common Data Types
Data Type Commonly Used Names
Number Smallint, integer, Bigint, decimal, Money
Number (auto) Serial, BigSerial
Enum Enum data types stored
Character Char, nchar, Text
Binary Bytea
Date Time Timestamp with timezone, Timestamp without Timezone, interval
Collections Array, JSON, JSONB
Misc Boolean, UUID, Geo Types, Network Address Mac Address, Custom Types
Full Text Search TsVector, TsQuery
See details from tutorials point

14. Special Data Types
• Collections
• Arrays
• Range Types
• Searchable
• Indexable
• Aggregate functions
Credit: Igal Sapir slides

15. JSON Datatypes
• Equivalent to embedded MongoDB
Credit: postgresql documentation
Notable Functions Description
::JSONB Casting
|| or JSONB_SET or
JSONB_BUILD_OBJECT
Build or set JSONB values
JSONB_AGG &
JSONB_BUILD_ARRAY
Aggregate functions
JSONB_PATH_*,
JSONB_EACH,
JSONB_EXTRACT
Path & Extract Functions
JSONB DEMO

16. Advanced Data Types
• Pivot Tables crosstab function
• Materialized Views
• HStore
• EXPLAIN ANALYZE
• Pg_stat
• XML Columns (not much used)

17. Concurrency - MVCC
• Postgres uses “Multi-version concurrency control”.
• Isolation at “read-committed” level
• Row level locks are explicit
• Same technique used in Oracle, CouchDB, etc

18. Indexes
• Index Support
• Single Column / Exact Matches
• Multi Column
• Unique
• Partial Indexes
• Expression Indexes
• Implicit Indexes (PK, UK)
Credit: Igal Sapir slides

19. Disadvantages / Limits
• Database only solution
• Few available tools
compared to commercial
• Limited Talent Pool
Source: https://www.youtube.com/watch?v=6p2TNPabt6M
Source: Postgres limits from sreenstepslive.com

20. Best Practices
• Performance Optimization
• Do not read from Database at all
• Use indexes efficiently
• Use pg_stats collector to monitor usage and performance
• Vacuum regularly to clean up storage
• Bench mark hardware and optimize pg parameters
• Always use SSL for connectivity in untrusted networks

21. Reasons to Fill Out Session Evaluations
Helps Speakers
Helps Organizers
Helps You!

22. References and Follow up
• Postgresql Documentatoin
• Igal Sapir Postgresql Presentation
• Introduction to Postgresql slideshare
• The Internals of Postgresql
• Postgresql excercises
• MVCC: postgres internals or interdb
Questions? Contact me at ramu@botsplash.com