March 24, 1997

Finding Two Equal Sets of Data

Question: [Joe Celko’s Equal Sets Puzzle]Set theory has two symbols for subsets. One is a “horseshoe” on its side, which means that set A is contained within set B and

Column lengths

Question: Data field objects in OPO can accept any amount of data, but if I send too many characters to the server, I get an error “flushing the row to

Normalized Database: When to Split?

Question: We have several heavily-used tables with lots of columns (average around 30 columns), and the users are getting locked out frequently. We’ve thought about splitting the tables, but didn’t

Lock Conflicts

Question: Our system is experiencing several lock conflicts. We’ve got a consultantlooking at the details, but I was hoping you could explain what’s going onbehind the scenes when records are

Differences Between Join Types

Question: What are the differences between LEFT, RIGHT, INNER and OUTER JOINS? Answer: An INNER JOIN is the most common type: It combines all the data from the tables specified

Data Replication as a WAN Solution

Question: I have nine offices. I want each office to connect across aWAN and run client/server applications with all datacontained on one central server. However, we are finding the delays

BLOB Data Storage

Question: What are the advantages/disadvantages of putting large binary files (1+ MB) in BLOB columns versus storing them on a file server with a reference such as a directory/file spec

Checking for a lost connection

Question: I want to periodically check to see if a user’s database connection has been lost. How can I? Answer: First of all, a solution. You can implement periodic ‘polling’

Improving performance

Question: The repeater in my application seems to be very slow in populating. Is there anything I can do to improve its performance? Answer: Poor performance can be the result