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visits member for 2 years, 8 months
seen Dec 19 at 7:48

Nov
24
comment Professor told us to store serialized Java objects as blobs instead of defining relational tables
"The answer by Justin Cave says, that you should go with the second option." That is not true. The answer by Justin Cave said that if you wanted to store serialized objects, you're better off doing it in a (the) file system.
Sep
12
comment DB2 developers can't create table in own schema but SQL and Oracle devs can. Justified?
Well if your agenda is just to dismiss the mainframe as "legacy" technology, there's obviously a lot left for you to learn, and a few comments or answers here won't suffice to do the job. Just be aware that providing isolated environments on the mainframe is most of all an economical (financial) problem, not a technological one.
Sep
11
comment DB2 developers can't create table in own schema but SQL and Oracle devs can. Justified?
Perhaps too philosophical, but the essence of a mainframe is to share. And the software that runs on it typically reflects that essence.
Jul
14
comment Slow DELETE in MySQL with a subquery
Aaaaargh. stackoverflow.com/questions/45494/… Apply solutions suggested over there or switch to a better dbms.
Jul
11
revised Slow DELETE in MySQL with a subquery
spelled out in more detail how to apply suggested changes.
Jul
11
answered Slow DELETE in MySQL with a subquery
May
19
comment How to SELECT multiple COUNT(*) columns with each GROUP BY having a different WHERE clause?
Are you sure RIGHT outer join is the correct thing to use ?
Apr
20
awarded  Yearling
Apr
1
comment Find actual data size from a query?
"Size" is not a property of "data".
Jan
16
answered SQL Server auto-trim of varchar value in equal comparison but not like comparison
Jan
3
comment An example of a relation without any functional dependency?
You should strike through that incorrect sentence where you say "yes, I believe". Then what remains is the correct answer.
Jan
3
comment Find the highest graded student, using Tuple Relational Calculus
"Tuple relational calculus does not have a set difference operator"
Oct
9
comment How to get performance benefits from a view vs subquery?
More importantly, if a CTE is referenced multiple times, this fact by itself is not sufficient to deduce that the optimal access paths for each of the contexts in which they appear are also identical. Think any CTE, with attributes say A and B, being tested once for "does it contain a tuple where A=1" and elsewhere being tested for "does it contain a tuple where B=7". The CTE is the same, the optimal access paths for the two usages of the CTE most likely aren't, and neither of them necessarily involves full evaluation.
Aug
16
answered Relations, dependencies and normal form
May
13
awarded  Caucus
Apr
20
awarded  Yearling
Apr
10
answered Column partially determining accepted values of another column, should be somehow normalized?
Apr
3
comment Handling expiration in a course registration or ticketing system
And in addition, create views such as REGISTRATION_EXPIRED_WITHOUT_PAYMENT and REGISTRATION_UNPAID_UNEXPIRED.
Apr
3
answered What happens to a Trigger if a table is dropped and rename and recreated with same name
Mar
28
awarded  Quorum