This page is for reviewing the 10.2 ''Derby Tuning Guide''.

This page just has initial Section Summary and Sub Section Details set up. The Reference Manual has a complete review setup.

Section Summary

Please list the sections you intend to review in the summary table below:

Section Name

Reviewers

Status

Working with Derby properties

Performance tips and tricks

Tuning databases and applications

DML statements and performance

Selectivity and cardinality statistics

Rajesh

Complete

Derby properties

Rajesh

Complete

Internal language transformations

Rajesh

In Progress

Sub Section Details

As you spot issues please add specific comments to the tables below, paying attention to the guidelines. For very extensive comments, please post to derby-dev or Jira instead, then include the URL in the Comment field.

Working with Derby properties :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Performance tips and tricks :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Tuning databases and applications :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

DML statements and performance :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Selectivity and cardinality statistics :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Derby properties :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Internal language transformations :

Sub Section

HTML Url or PDF Page

Reviewer

Comment

Resolution

Unknown parameter

http://db.apache.org/derby/docs/dev/tuning/rtuntransform472.html

Rajesh

There is a mention of rewriting queries - "Users can work around this possibility by writing the query like this (which is not optimizable):(country... ) LIKE ?". But this does not mention the rationale for doing so, which could be benefical for the users in understanding the transformation.

Derby-1946 opened to address this issue https://issues.apache.org/jira/browse/DERBY-1946

Predicates pushed into views or derived tables

http://db.apache.org/derby/docs/dev/tuning/ctuntransform36623.html

Rajesh

Typo - "Pushing down means that the qualification described by the predicate can be evaluation..." should be "Pushing down means that the qualification described by the predicate can be evaluated..."

Fixed (Laura)

Predicates pushed into views or derived tables

http://db.apache.org/derby/docs/dev/tuning/ctuntransform36623.html

Rajesh

Query - "SELECT a, b FROM (SELECT sales_person, MAX(sales) from Sales WHERE city_id = 2 GROUP BY city_id) v1(a, b)" does not seem correct, I think the correct one is "SELECT a, b FROM (SELECT sales_person, MAX(sales) from Sales WHERE sales_person = 'LUCCHESSI' GROUP BY sales_person) v1(a, b)"

Fixed (Laura)

TuningTenTwo (last edited 2009-09-20 22:12:04 by localhost)