Debbie asked a question about why a comparison wasn’t working in the Microsoft Excel SUMIF function when the initial array value was empty. This post answers that question.

The SUMIF function takes a lookup range, which anticipates a one column with a lookup value and another column with a value. The SUMIFS function works along the same line but accepts multiple lookups against a series of lookup list columns.

select *
from keys;

TYPE DESCRIPTION
--------- -----------------------------------
Primary The premier way to locate a row
Foreign Xenophilic links to other tables
Candidate Wished it could be primary, but had
to settle for uniqueness
Whis The amber nectar that keeps me sane
A database without any of the first three constraints
causes me to pour a large glass of the fourth!

create sequence of_endlessly_repeating_digits
cache 2 cycle maxvalue 10;

select of_endlessly_repeating_digits.nextval
from dual
connect by level <= 100;
I've never found a particularly good use for cycling sequences, but I guess they must come in handy somewhere...

select *
from bitmap_index;

DESCRIPTION
-------------------------------------------
Using 1s and 0s to represent data values
A treasure hunter's missing piece nightmareIn both cases the bit[of a]map helps people with their searches!