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Oct
18
comment dynamic table can't be accessed by the users
Which DBMS are you using? Postgres? Oracle?
Oct
17
comment PostgreSQL how to change to Repeatable read
If in doubt, read the manual: postgresql.org/docs/current/static/…
Oct
17
comment Why is MySQL Server software so huge?
You only think it's huge until you download Oracle: that's approx. 4.5 GB
Oct
17
comment Join 3 tables and return only distinct values for max datetime
@DeLL It seems you are using a DB2 version that does not support window function. I though all DB2 versions - including the host based ones - support this (it is definitely valid for DB2 LUW)
Oct
17
comment Join 3 tables and return only distinct values for max datetime
@ypercube: the condition WHERE A.TRANNO=(SELECT MAX(TRANNO) FROM tableA A where A.CASENO=B.CASENO) implies partition by a.caseno to me.
Oct
17
comment How to handle big table?
"it would take one day" - how did you com to this conclusion? Please read this: wiki.postgresql.org/wiki/SlowQueryQuestions and add the missing information (namely: the execution plans)
Oct
17
comment Join 3 tables and return only distinct values for max datetime
"where a.date between 140124 and 140331" - are you really storing dates as integers like that? And why do you split the date and the time into two different (integer) columns? It will be much better to use a proper timestamp column instead.
Oct
16
comment PostgreSQL return second 'Group' as an array
@DaveB: you are right. I forgot that.
Oct
16
comment Postgres top-k with ties
@Alexandros: sorry, I have no idea what you mean. Can you add more sample data to your question?
Oct
16
comment Rows are not getting deleted from MySQL Table
Does the "federated" storage engine support transactions? Maybe you are simply missing a commit?
Oct
16
comment PostgreSQL return second 'Group' as an array
@ClaesMogren: good point, fixed.
Oct
16
comment Where does mysql store data?
@Konrad: that's actually pretty common. Oracle and SQL Server also store everything in a single file (although you can configure them differently)
Oct
16
comment Self Join? Or am I wrong?
I think this is because MINUS was introduced in Oracle long before this was defined in the SQL standard.
Oct
16
comment Self Join? Or am I wrong?
minus is Oracle specific. The SQL standard defines except
Oct
16
comment Postgres top-k with ties
@Alexandros: see my edit. By doing this in two "steps", this *could*(!) be faster. But you will have to check the execution plan with your real life data.
Oct
16
comment Creating a rule increases load disproportionally
How do the involved tables look like? How does the rule look like? What are the statements that fire the rule? How big (=number of rows) are the tables? Which indexes are defined on the tables?
Oct
16
comment Find the sid of suppliers who supply every red part
Which DBMS are you using? Postgres? Oracle?
Oct
16
comment Oracle Concurrent Insertion
Session2 will not hang. Why don't you just try for yourself? This is really easy to test
Oct
15
comment postgresql replace table without losing dependancies
I have never seen a create or replace table in any other DBMS (Oracle, SQL Server, DB2, Firebird, HSQLDB, ....)
Oct
15
comment postgresql replace table without losing dependancies
What's wrong with using ALTER TABLE?