db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Rajesh Kartha (JIRA)" <derby-...@db.apache.org>
Subject [jira] Commented: (DERBY-384) Doc Review: Tuning Derby
Date Fri, 24 Jun 2005 00:10:10 GMT
    [ http://issues.apache.org/jira/browse/DERBY-384?page=comments#action_12314373 ] 

Rajesh Kartha commented on DERBY-384:

I started reviewing the Tuning Derby manual and here are some of the suggestions I have so

Page Number:                                             Changes

page -  9: 'In the derby.properties file'  heading could be made 'The derby.properties file'
page - 13:  See Index, index, index for more information. (multiple mention of the word 'index')

page - 18:  1. Index, index, index  (multiple mention of the word 'index')

page - 18:  Index, index, index 	(multiple mention of the word 'index')

page - 18: Note: For a complete discussion of how indexes work and when they are useful
		(including pictures) [there are no pictures in the manual??]

page - 18: Note: Derby does not support indexing long columns. 
	  (Could be misleading. Need Examples. Hence the statment can be made
	"Note: Derby does not support indexing long columns like CLOB and BLOB")

	[ <reference>
	HERE IS AN EXAMPLE that works for bigint and long varchar for bit data:
	ij> create table TBIGINT(id bigint, c long varchar for bit data);
	0 rows inserted/updated/deleted
	ij> create index id1 on tbigint(id);
	0 rows inserted/updated/deleted
	ij> create index id2 on tbigint(c);
	0 rows inserted/updated/deleted 

	Here is one that does not work - using CLOB

	ij> create table TCLOB(id bigint, c clob);
	0 rows inserted/updated/deleted
	ij> create index id3 on tclob(c);
	ERROR X0X67: Columns of type 'CLOB' may not be used in CREATE INDEX, ORDER BY, G
	ROUP BY, UNION, INTERSECT, EXCEPT or DISTINCT statements because comparisons are
	 not supported for that type.

page - 19: Difference between an descending and an ascending index ? This needs to confirmed,
 the reasons cited
                    is not convincing. A ascending index can also 1) get min and max values
2) be useful for sorting data

page - 19: The example under "Think about order" and the description does not match. The example
	   select with a joing of flights and flightavailability tables whereas the description talks
	   about hotels and hotelavailability. Also there is reference to the toursDB database.

page - 19: Example:
	-- CREATE INDEX c_id_desc ON Citites(city_id DESC)
		SELECT * FROM Cities ORDER BY citiy_id DESC 
      should be 
      -- CREATE INDEX c_id_desc ON Cities(city_id DESC)
		SELECT * FROM Cities ORDER BY city_id DESC 
More as I read along...

> Doc Review: Tuning Derby
> ------------------------
>          Key: DERBY-384
>          URL: http://issues.apache.org/jira/browse/DERBY-384
>      Project: Derby
>         Type: Improvement
>   Components: Documentation
>  Environment: all
>     Reporter: Jeff Levitt
>     Priority: Minor
>      Fix For:

> This issue tracks comments for the manual known as Tuning Derby. The deadline for posting
comments is Tuesday, June 28, noon Pacific time.
> Some guidelines to follow when posting comments to this issue are:
> - Try to make clear and concise comments about what you want changed whenever possible.
 Provide concrete comments that say "Please change <original> to <modified>" instead
of generic comments like "This section needs to be rewritten."
> - If you're reviewing the HTML Files copy, include the URL for the page in the review
comment. Obtain the URL like this:
>     * highlight the topic in the left frame
>     * right click
>     * choose "Properties"
>     * copy and paste the address in the pop up box.
> - If you're reviewing the PDF copy, in the review comment:
>     * Include the page number for the PDF, and indicate whether the number is the PDF
sheet number or the printed page number.
>     * Include the title of the section that the problem occurs in. If it's in a subsection,
try to include the hierarchy of titles.
> - Please don't review the HTML Book copy -- it'll be time consuming to match up that
copy with the underlying DITA source.

This message is automatically generated by JIRA.
If you think it was sent incorrectly contact one of the administrators:
For more information on JIRA, see:

View raw message