tomcat5 start-stop @winxp

the windows service is not convenient

Solution: bintomcat5.exe, with feature 1

–feature 1: the familiar dos window showing console. U also can see
if the server is running.


log4j.xml quick guide

q: threshold?
A: The “threshold” attribute takes a level value such that all
logging statements with a level equal or below this value are

Q: root?
A: root of the xml tree is CATEGORY, which typicall references
1 or more appenders, 2nd level node in the xml tree.

Q: eg@appenders?
A: console, snmp, syslog,

q: log4j.xml changes need restart?
A: no

Q: category vs logger?
A: say “category” in xml; say “logger” in src code
#1 tip: child logger inherits from parent logger

Q: Category names are FQCN?
A: yes. “Engine” shown in console but “com.domain.Engine” shown in log file.


simplest intro2nested-loop join

A basic but clear understanding of the nested-loop concept is fundamental to correlated queries and join-order tuning.

based on

foreach row r in R do
foreach row s in S do
if r(i) == s(j) then pass the combined row r + s to further processing

R is the driving-table.
r(i) is taken as a constant in the inner loop


each perl class has its namespace

A perl class (always?) has a unique namespace. To clarify things, a novice should try to spell out package qualified identifiers like
— @myClass1::ISA
— myClass2::my_method8

“A class is simply a package”, and (in another post) a package represents a namespace.