Links

http://www.techonthenet.com/oracle/sys_tables/ -- Commonly used Oracle System Tables

My Interview Questions :)

IF : more than one if/elsif condition satisfied then all or first ?
FOR i IN 3..3 LOOP statement1; END LOOP; -- how many times?
Null AND FALSE?
NULL OR TRUE?

Interview Questions

set operators

My weak concepts...

constraints for calling functions in sql

Open Questions

When do we use " instead of '?
A PL/SQL program is terminated and executed by a slash (/) on a line by itself.

Notes

Oracle9i can scale tens of thousands of concurrent users, support up to 512 petabytes of data (a petabyte is 1,000 terabytes), and can handle any type of data, including text, spatial, image, sound, video, and time series as well as traditional structured data.
Prior to Oracle9i, user defined functions can be only single-row functions. Starting with Oracle9i, user-defined functions can also be defined as aggregate functions.

Conceptual Info.

• Explain that BETWEEN … AND … is actually translated by the Oracle server to a pair of AND conditions (a >= lower limit) and (a <= higher limit) and IN ( … ) is translated by the Oracle server to a set of OR conditions (a = value1 OR a = value2 OR a = value3). So using BETWEEN … AND … , IN(…) has no performance benefits; the benefit is logical simplicity.
• Oracle issues an implicit commit before and after any data definition language (DDL) statement. So, even if your DDL statement does not execute successfully, you cannot roll back the previous statement because the server issued a commit.
• Tables can have up to 1,000 columns
• Table names and column names (tough to remember terms only):

1. Must begin with a letter
2. Must be 1–30 characters long
3. Must contain only A–Z, a–z, 0–9, _, $, and #