LUW: Linux & Unix & Windows platfoms
SQL optimize
Where -> Group -> Having -> Oder -> Select
Index Usage: Index -> Table Space-> Stage 1 -> Stage 2
SQLCA: SQL Conmmunication Area
SQLDA: SQL Describtion Area
QMF: some version for windows platform, press F12 to set and print report
Spufi
SELECT FROM A,B meant A*B
Don`t use SELECT *, LIKE '%_A3DF', DELETE FROM, if you want to empty a table, you`d better to load a empty file to this table, this aproach can avoid fullfilling logfile in your own space.
PL1: EBCDIC, TABLE: UNIONCODE, this difference may couse SQLCODE=-000 when you are going to unload a table as a warning, then the load activity is terminated.
(comm/12): stage 2
One plan has many connections, the different connections can contain packages with the same name. The when a program is calling package, it will get the first one, for example package 1 -> package 2.
CURSOR: FETCH CORSOR ... ORDER BY... it will load data into a temporary file to do this order, very slowly if big data.
JAVA -> JDBC -> RUN TIME ENVIRONMENT
