Major Features: Postgres 9.6

BRUCE MOMJIAN

POSTGRESQL is an open-source, full-featured relational database.This presentation gives an overview of the Postgres 9.6 release.Creative Commons Attribution License http://momjian.us/presentationsLast updated: September, 2016

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PostgreSQL the database…

! Open Source Object Relational DBMS since 1996

! Distributed under the PostgreSQL License

! Similar technical heritage as Oracle, SQL Server & DB2

! However, a strong adherence to standards (ANSI-SQL 2008)

! Highly extensible and adaptable design

! Languages, indexing, data types, etc.! E.g. PostGIS, JSONB, SQL/MED

! Extensive use throughout the world for applications andorganizations of all types

! Bundled into Red Hat Enterprise Linux, Ubuntu, CentOSand Amazon Linux

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PostgreSQL the community…

! Independent community led by a Core Team of six

! Large, active and vibrant community

! www.postgresql.org

! Downloads, Mailing lists, Documentation

! Sponsors sampler:

! Google, Red Hat, VMWare, Skype, Salesforce, HP andEnterpriseDB

! http://www.postgresql.org/community/

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EnterpriseDB the company…

! Leading worldwide provider of Postgres software and services

! More than 3,500 enterprises, governments, and otherorganizations worldwide

! EDB Postgres Platform with:

! PostgreSQL and EDB Postgres Advanced Server includingadditional enterprise functionaility

! Tool Suites for Management, Integration, and Migration,including High Availability and Disaster Recovery

! Professional Services, 24/7 global support, and Remote DBA! Training and Certification

! Citizenship

! Contributor of key features: Materialized Views, JSON, &more

! Nine community members on staff

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EnterpriseDB the company…

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EnterpriseDB Is a Leader

The Gartner report, Magic Quadrant for Operational Database Management Systems, by

Donald Feinberg, Merv Adrian, Nick Heudecker, Adam Ronthal, and Terilyn Palanca was

published October 12, 2015.6 / 20

9.6 Feature Outline1. Parallel execution of sequential scans, joins and aggregates

2. Avoid scanning pages unnecessarily during vacuum freezeoperations

3. Synchronous replication now allows multiple standby serversfor increased reliability

4. Full-text search can now search for phrases (multipleadjacent words)

5. postgres_fdw now supports remote joins, sorts, UPDATEs,and DELETEs

6. Substantial performance improvements, especially in thearea of scalability on multi-CPU-socket servers

7. Allow limiting of snapshot age

8. New monitoring capabilities

9. Allow long-idle transactions to be cancelled

Full item list at http://www.postgresql.org/docs/devel/static/release-9-6.html

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1. Parallel Execution of Sequential Scans,Joins and Aggregates

CREATE TABLE partest (x INTEGER);

INSERT INTO partest

SELECT * FROM generate_series(1, 2000000);

EXPLAIN SELECT count(*) FROM partest;QUERY PLAN

-----------------------------------------------------------------------Aggregate (cost=37059.38..37059.39 rows=1 width=8)

-> Seq Scan on partest (cost=0.00..31417.50 rows=2256750 width=0)

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Parallel Aggregate and Sequential Scan

SET max_parallel_workers_per_gather = 8;

EXPLAIN SELECT count(*) FROM partest;QUERY PLAN

-----------------------------------------------------------------Finalize Aggregate (cost=21604.12..21604.13 rows=1 width=8)

-> Gather (cost=21603.90..21604.11 rows=2 width=8)Workers Planned: 2-> Partial Aggregate (cost=20603.90..20603.91 row…

-> Parallel Seq Scan on partest (cost=0.00..…

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2. Avoid Scanning Pages UnnecessarilyDuring Vacuum Freeze Operations

! Freezing of tables is occasionally necessary to guarantee safetransaction id wraparound

! Usually performed by autovacuum

! Previously it scanned all heap pages! Now, only pages modified since the last freeze are scanned

! Great benefit for rarely-written tables

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3. Synchronous Replication Now Allows MultipleStandby Servers for Increased Reliability

! synchronous_standby_names controls which standby serversthe primary waits for to confirm commit

! Previously, if multiple were specified, only the first connectedstandby was waited for

! Now, you can specify the number of connected standbys towait for, e.g. 2 (standby1, standby2, standby3)

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4. Full-text Search Can Now Searchfor Phrases (Multiple Adjacent Words)

! You can now search for words positioned relative to otherwords

! ’ice <-> cream’ matches strings with ’ice’ and ’cream’adjacent and in order

! ’mutually <2> destruction’ matches a word in between

! phraseto_tsquery() creates a tsquery with <-> betweeneach supplied word

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5. postgres_fdw Now Supports RemoteJoins, Sorts, UPDATEs, and DELETEs

SQL Queries

Join, Sort

PG FDW

UPDATE, DELETE

Foreign Server Foreign Server Foreign Server

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6. Substantial Performance Improvements,Especially in the Area of Scalabilityon Multi-CPU-Socket Servers

! Sorting

! Locking, especially for shared buffers

! Checkpoints

! Aggregates

! File growth! Process title updates on Windows

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7. Allow Limiting of Snapshot Age

Seession 1 Session 2

SHOW old_snapshot_threshold;

1min

CREATE TABLE snaptest (x int);

INSERT INTO snaptest VALUES (1);

BEGIN WORK;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SELECT * FROM snaptest;

1

UPDATE SNAPTEST SET x = 2;

SELECT pg_sleep(300);

VACUUM snaptest;

SELECT * FROM snaptest;

ERROR: snapshot too old

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8. New Monitoring Capabilities

! pg_stat_activity wait-type reporting

! Vacuum progress reporting

! pg_config system view

! pg_control values exposed

! New system view to monitor WAL receiver status

! Notification queue monitoring

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9. Allow Long-idle Transactions To Be Cancelled

SET idle_in_transaction_session_timeout = ’2s’;

BEGIN WORK;-- sit idle for 3 secondsSELECT 1;FATAL: terminating connection due to idle-in-transaction timeoutserver closed the connection unexpectedly

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Possible 10 Features

! Additional parallelism

! FDW enhancements for sharding! Partitioning syntax

! Built-in logical replication

! HOT improvements

! Multivariate statistics

! Client-side failover

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Additional Resources…

! Postgres Downloads:

! www.enterprisedb.com/downloads

! Product and Services information:

! info@enterprisedb.com

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Conclusion

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