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Sat Sep 09 00:15:42 HKT 2017


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Mon Jan 07 22:17:37 HKT 2008 From /weblog/database


Nice article of discussing pros and cons of using stored procedures:[..]uments-for-and-against-using-stored.html

I still like to prevent it as most SP still look ugly in my own opinons.... here is another article that mostly against SP -[..]yth-of-stored-procedures-preference.aspx

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Sat Dec 15 18:42:26 HKT 2007 From /weblog/database


Amazon simple DB service

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Wed Nov 14 19:05:19 HKT 2007 From /weblog/database


An arguement of use / not use RDBMS[..]gView?showComments=true&entry=3366636502 .

Hsql is a very nice tool for development: fast, support most sql standard, easy to setup. In addition, there is a one really nice feature. It will store the INSERT, UPDATE and DELETE statement in a script file to persist the database status. This make debug a lot simpler. Highly recommend!

Besides, a nice introduction of SQLite and Java Berkeley DB -[..]operWorks/cn/java/l-embed-db/index.shtml

A solution of close don't commit data to disk:[..]ion-close-doesnt-write-to-disk-solution/ but for me this is feature than bug, as I can easily keep my data back to the copy I want.

A document base DB, it is not hold a table ( or relation ) , it hold a Document , what I understand it is a map -

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Mon Oct 15 19:32:55 HKT 2007 From /weblog/database/sql

ansi joining

A nice article about standard ANSI joining syntax:

Recognizing well known patterns involving outer joins will form a ground-level vocabulary for your further explorations of your data. This article examined syntax, surprises, and rules of thumb with respect to the usage of joins.

A blog with nice graphic show how join work -

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Wed Jun 13 23:34:34 HKT 2007 From /weblog/database/sql

solve sudoku in sql

A very complicate TSQL sample... in my opinions:

Even more implementation -

which introduce some interesting function in vendor specific SQL, like Oracle MODEL -[..]erver.102/b14223/sqlmodel.htm#sthref1855

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Wed Apr 11 00:51:38 HKT 2007 From /weblog/database


The one I long for is the SQL Exception Handling Enhancements, look like I don't need to issue an select everytime before insert or delete to prevent SQL exception from duplicate record or foreign key constraint

However, not sure why we need Annotation-Based SQL Queries, better than putting SQL as String?[..]day/2007/04/10/whats-new-in-jdbc-40.html

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Fri Mar 30 19:22:20 HKT 2007 From /weblog/database/transaction

Transactionless system

Improve scalability via turn off transaction... do you think it will work?

I think this Idempotency help a lot if we like to implement system in this way: or example is soft update

Follow up discussion -

Already get two comments from friends, there is the key points:

=== Rob
Not if everything works as intended. But if something goes wrong you might get an unexpected state in the database. Then you have to do more work in other places to deal with the fact that the database might be in a state that wasn't intended, but is theoretically possible because you didn't use transactions.
=== Rex
Rex: exactly the thing what i did in last year to boost up performance from 700 txn per second to more than 10K txn per second.
Carfield Yim: handle rollback yourself you mean?
u've to understand what is a system before talking the details...
different application can apply different rollback.
online/batch different are different.

Rule 1. make your txn simple.
if it can't be simple, your design must have problem

u have to understand your capacity & limitation..... such article is meaningless if you have no actual requirement...
if client is requiring 500 txn, that's no pt to have it like that.

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Fri Dec 15 16:28:23 HKT 2006 From /weblog/database

model tree in set

We usually format tree structure using adjacency list, however, it also able to present in a set. Which spend more work on [create, delete, update] operations, but achieve much better query performance.[..]com/tip/1,289483,sid13_gci537290,00.html[..]com/tip/1,289483,sid13_gci801943,00.html[..]firefox-a&rls=org.mozilla:en-US:official

Java example -

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Mon Nov 06 01:50:35 HKT 2006 From /weblog/database

regression test

Automate data test -

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Wed Oct 18 16:17:25 HKT 2006 From /weblog/database


Various problems from various databases

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Thu Oct 12 17:33:03 HKT 2006 From /weblog/database/objective

Transparent persistent

Transparent Persistence is a marketing term (that means "lie"), it isn't. However, because you need to spend far less effort on persistence you tend to really want it to be true, and code as if it is.
Probably, what we all need to do, is to remove the word "transparent" from "transparent o/r mapping" and admit that it is simply a high level tool, be up front about the design considerations, and talk a lot more about how to design applications using these tools rather than what the tools can do.

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Wed Jun 07 16:40:48 HKT 2006 From /weblog/database

Order-by side effect

Do not use ORDER BY if the query has a DISTINCT or GROUP BY on the same set of terms, because they have the side effect of ordering rows

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Sun May 28 18:34:11 HKT 2006 From /weblog/database

jdbc proxy

a list of jdbc proxy:[..]/debugging-jdbc-with-logging-driver.html

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Fri Jan 20 12:30:07 HKT 2006 From /weblog/database

Managing PetaByte Database

Nice to read:[..]06/01/worlds-largest-database-babar.html

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Mon Nov 28 17:33:19 HKT 2005 From /weblog/database

Gavin King interview

Interview Hibernate creator, a nice reading

JPT: Have your original ideas about O/R mapping changed much since you embarked on this project?

Gavin King: I went into this knowing very little about ORM, and even very little about databases. One of my first tasks was to go out and buy a book to learn SQL properly. All my understanding of the problem comes from what our users have taught us over the last two years.

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Sat Nov 19 17:23:24 HKT 2005 From /weblog/database

Tip to remove duplication

Fix for: Missing primary key + duplication record + large table

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Fri Nov 18 12:45:05 HKT 2005 From /weblog/database

Myth Of Data Integrity

A nice blog discuss about data integrity

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Wed Oct 26 17:11:22 HKT 2005 From /weblog/database

domain object cache

Discuss about ehcache, I think this is a nice discussion about possible issue of disk base caching (e.g.: persist generated HTML at disk so that don't need to waste time to generate HTML again and again)

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Mon Oct 24 18:16:27 HKT 2005 From /weblog/database

commit before close

Just know that calling Connection.close() can result in either commit or rollback. It depend DBMS only

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