Mastering PostgreSQL 9.6电子书

Title Page

Copyright

Credits

About the Author

About the Reviewer

www.PacktPub.com

Customer Feedback

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

PostgreSQL Overview

What is new in PostgreSQL 9.6?

Understanding new database administration functions

Killing idle sessions

Finding more detailed information in pg_stat_activity

Tracking vaccum progress

Improving vacuum speed

Digging into new SQL and developer-related functions

Using new backup and replication functionality

Streamlining wal_level and monitoring

Using multiple synchronous standby servers

Understanding performance-related features

Improving relation extensions

Checkpoint sorting and kernel interaction

Using more advanced foreign data wrappers

Introducing parallel queries

Adding snapshot too old

Summary

Understanding Transactions and Locking

Working with PostgreSQL transactions

Handling errors inside a transaction

Making use of savepoints

Transactional DDLs

Understanding basic locking

Avoiding typical mistakes and explicit locking

Considering alternative solutions

Making use of FOR SHARE and FOR UPDATE

Understanding transaction isolation levels

Considering SSI transactions

Observing deadlocks and similar issues

Utilizing advisory locks

Optimizing storage and managing cleanup

Configuring VACUUM and autovacuum

Digging into transaction wraparound-related issues

A word on VACUUM FULL

Watching VACUUM at work

Making use of snapshot too old

Summary

Making Use of Indexes

Understanding simple queries and the cost model

Making use of EXPLAIN

Digging into the PostgreSQL cost model

Deploying simple indexes

Making use of sorted output

Using more than one index at a time

Using bitmap scans effectively

Using indexes in an intelligent way

Improving speed using clustered tables

Clustering tables

Making use of index only scans

Understanding additional B-tree features

Combined indexes

Adding functional indexes

Reducing space consumption

Adding data while indexing

Introducing operator classes

Hacking up an operator class for a B-tree

Creating new operators

Creating operator classes

Testing custom operator classes

Understanding PostgreSQL index types

Hash indexes

GiST indexes

Understanding how GiST works

Extending GiST

GIN indexes

Extending GIN

SP-GiST indexes

BRIN indexes

Extending BRIN indexes

Adding additional indexes

Achieving better answers with fuzzy searching

Taking advantage of pg_trgm

Speed up LIKE queries

Handling regular expressions

Understanding full-text search - FTS

Comparing strings

Defining GIN indexes

Debugging your search

Gathering word statistics

Taking advantage of exclusion operators

Summary

Handling Advanced SQL

Introducing grouping sets

Loading some sample data

Applying grouping sets

Investigating performance

Combining grouping sets with the FILTER clause

Making use of ordered sets

Understanding hypothetical aggregates

Utilizing windowing functions and analytics

Partitioning data

Ordering data inside a window

Using sliding windows

Abstracting window clauses

Making use of onboard windowing functions

rank and dense_rank functions

ntile() function

lead() and lag() functions

first_value(), nth_value(), and last_value() functions

row_number() function

Writing your own aggregates

Creating simple aggregates

Adding support for parallel queries

Improving efficiency

Writing hypothetical aggregates

Summary

Log Files and System Statistics

Gathering runtime statistics

Working with PostgreSQL system views

Checking live traffic

Inspecting databases

Inspecting tables

Making sense of pg_stat_user_tables

Digging into indexes

Tracking the background worker

Tracking, archiving, and streaming

Checking SSL connections

Inspecting transactions in real time

Tracking vacuum progress

Using pg_stat_statements

Creating log files

Configuring postgresql.conf file

Defining log destination and rotation

Configuring syslog

Logging slow queries

Defining what and how to log

Summary

Optimizing Queries for Good Performance

Learning what the optimizer does

Optimizations by example

Evaluating join options

Nested loops

Hash joins

Merge joins

Applying transformations

Inlining the view

Flattening subselects

Applying equality constraints

Exhaustive searching

Trying it all out

Making the process fail

Constant folding

Understanding function inlining

Join pruning

Speedup set operations

Understanding execution plans

Approaching plans systematically

Making EXPLAIN more verbose

Spotting problems

Spotting changes in runtime

Inspecting estimates

Inspecting buffer usage

Fixing high buffer usage

Understanding and fixing joins

Getting joins right

Processing outer joins

Understanding the join_collapse_limit variable

Enabling and disabling optimizer settings

Understanding genetic query optimization

Partitioning data

Creating partitions

Applying table constraints

Modifying inherited structures

Moving tables in and out of partitioned structures

Cleaning up data

Adjusting parameters for good query performance

Speeding up sorting

Speedup administrative tasks

Summary

Writing Stored Procedures

Understanding stored procedure languages

The anatomy of a stored procedure

Introducing dollar quoting

Making use of anonymous code blocks

Using functions and transactions

Understanding various stored procedure languages

Introducing PL/pgSQL

Handling quoting

Managing scopes

Understanding advanced error handling

Making use of GET DIAGNOSTICS

Using cursors to fetch data in chunks

Utilizing composite types

Writing triggers in PL/pgSQL

Introducing PL/Perl

Using PL/Perl for datatype abstraction

Deciding between PL/Perl and PL/PerlU

Making use of the SPI interface

Using SPI for set returning functions

Escaping in PL/Perl and support functions

Sharing data across function calls

Writing triggers in Perl

Introducing PL/Python

Writing simple PL/Python code

Using the SPI interface

Handling errors

Improving stored procedure performance

Reducing the number of function calls

Using cached plans

Assigning costs to functions

Using stored procedures

Summary

Managing PostgreSQL Security

Managing network security

Understanding bind addresses and connections

Inspecting connections and performance

Living in a world without TCP

Managing pg_hba.conf

Handling SSL

Handling instance-level security

Creating and modifying users

Defining database-level security

Adjusting schema-level permissions

Working with tables

Handling column-level security

Configuring default privileges

Digging into row-level security - RLS

Inspecting permissions

Reassigning objects and dropping users

Summary

Handling Backup and Recovery

Performing simple dumps

Running pg_dump

Passing passwords and connection information

Using environment variables

Making use of .pgpass

Using service files

Extracting subsets of data

Handling various data formats

Replaying backups

Handling global data

Summary

Making Sense of Backups and Replication

Understanding the transaction log

Looking at the transaction log

Understanding checkpoints

Optimizing the transaction log

Transaction log archiving and recovery

Configuring for archiving

Confguring the pg_hba.conf file

Creating base backups

Reducing the bandwidth of a backup

Mapping tablespaces

Using different formats

Testing transaction log archiving

Replaying the transaction log

Finding the right timestamp

Cleaning up the transaction log archive

Setting up asynchronous replication

Performing a basic setup

Improving security

Halting and resuming replication

Checking replication to ensure availability

Performing failovers and understanding timelines

Managing conflicts

Making replication more reliable

Upgrading to synchronous replication

Adjusting durability

Making use of replication slots

Handling physical replication slots

Handling logical replication slots

Use cases of logical slots

Summary

Deciding on Useful Extensions

Understanding how extensions work

Checking for available extensions

Making use of contrib modules

Using the adminpack

Applying bloom filters

Deploying btree_gist and btree_gin

Dblink - consider phasing out

Fetching files with file_fdw

Inspecting storage using pageinspect

Investigating caching with pg_buffercache

Encrypting data with pgcrypto

Prewarming caches with pg_prewarm

Inspecting performance with pg_stat_statements

Inspecting storage with pgstattuple

Fuzzy searches with pg_trgm

Connecting to remote servers using postgres_fdw

Handling mistakes and typos

Other useful extensions

Summary

Troubleshooting PostgreSQL

Approaching an unknown database

Inspecting pg_stat_activity

Querying pg_stat_activity

Treating Hibernate statements

Figuring out where queries come from

Checking for slow queries

Inspecting individual queries

Digging deeper with perf

Inspecting the log

Checking for missing indexes

Checking for memory and I/O

Understanding noteworthy error scenarios

Facing clog corruption

Understanding checkpoint messages

Managing corrupted data pages

Careless connection management

Fighting table bloat

Summary

Migrating to PostgreSQL

Migrating SQL statements to PostgreSQL

Using lateral joins

Supporting lateral

Using grouping sets

Supporting grouping sets

Using WITH clause - common table expressions

Supporting WITH clause

Using WITH RECURSIVE clause

Supporting WITH RECURSIVE clause

Using FILTER clause

Supporting FILTER clause

Using windowing functions

Supporting windowing and analytics

Using ordered sets - WITHIN GROUP clause

Supporting WITHIN GROUP clause

Using TABLESAMPLE clause

Supporting TABLESAMPLE clause

Using limit/offset

Supporting FETCH FIRST clause

Using OFFSET

Supporting OFFSET clause

Using temporal tables

Supporting temporal tables

Matching patterns in time series

Moving from Oracle to PostgreSQL

Using the oracle_fdw extension to move data

Using ora2pg to migrate from Oracle

Common pitfalls

Moving from MySQL or MariaDB to PostgreSQL

Handling data in MySQL and MariaDB

Changing column definitions

Handling null values

Expecting problems

Migrating data and schema

Using pg_chameleon

Using foreign data wrappers

Summary