The document outlines upcoming performance features in PostgreSQL 8.3, including: 1) Update Without Heap Only Tuples (HOT) which improves update performance by avoiding moving tuples during updates. 2) Asynchronous Commit And Checkpoint Smoothing which improves performance of commits and checkpoints. 3) Synchronized Scans which allows synchronized sequential scans to avoid duplicate work. 4) Autovacuum On By Default which automatically performs vacuum and analyze tasks to avoid performance degradation.

1. Upcoming PostgreSQL Performance Features
BRUCE MOMJIAN,
ENTERPRISEDB
September, 2007
Abstract
This outlines the upcoming performance features of PostgreSQL 8.3.

2. PostgreSQL Evolution
Crash SQL Standards Enterprise
86
96
98
01
07
19
19
19
20
20
11 Years
Enterprise features include:
Improved Performance
Simplified Maintenance and Administration
Efficient 24/7 Operation
Upcoming PostgreSQL Features 1

3. Update Without Heap Only Tuples (HOT)
Index 1 2 3
Page Header Item1 Item2 Item3
8K
UPDATE2
UPDATE1 INSERT Special
Upcoming PostgreSQL Features 2

4. Update With Heap Only Tuples (HOT)
Index 1
Page Header Item1 Item2 Item3
8K
UPDATE1 UPDATE2 Special
Upcoming PostgreSQL Features 3

5. Asynchronous Commit And
Checkpoint Smoothing
Upcoming PostgreSQL Features 4

6. Synchronized Scans
Session 1
Session 2
D D D D D D D D D D D D
A A A A A A A A A A A A
T T T T T T T T T T T T
A A A A A A A A A A A A
Heap
Upcoming PostgreSQL Features 5

7. Autovacuum On By Default
Autovacuum
Dead
Dead
Dead
Dead
Dead
Dead
Dead
Dead
Upcoming PostgreSQL Features 6

8. Short Varlena Headers
Two CHAR(1) fields, 16 bytes
length G padding length T padding
Two CHAR(1) fields, 4 bytes
len
len
G T
gth
gth
Short headers used for lengths less than 128 bytes. Also, the tuple header
is now 23 bytes, 4 bytes shorter.
Upcoming PostgreSQL Features 7

9. Other Performance Improvements
Now possible for LIMIT with ORDER BY to return matching rows
without sorting
New ring buffer for vacuums and large sequential scans avoids cache
wiping
Transaction ids no longer used for read-only transactions; reduces the
need for vacuum to prevent xid wrap-around
Auto-adjusted background writer
Upcoming PostgreSQL Features 8

10. Other Improvements
Full Text Search (tsearch2) installed by default
Updatable cursors (WHERE CURRENT OF)
Data types
– SQL/XML with syntax support
– UUID (universal unique identifier)
– ENUM
Upcoming PostgreSQL Features 9

11. Questions?
Upcoming PostgreSQL Features 10