March 14, 1997

Using Table Partitioning Features in XPS to Solve Old Data Problem

Question: Do the table partitioning features (fragmenting) in XPS solve the problem of unloading old data in a data warehouse?Specifically, I need to delete up to 400MB of old data from one table and insert 400MB of new data. Can I avoid locking and logging overhead by dropping a fragment

Updating a Table with Multiple Values

Question: Oracle 7.3, Microsoft Access 2.0 and up, and Microsoft SQL Server 6.5 all provide methods by which a single SQL command can update a table using multiple values looked up in another table (i.e. via a join). Oracle provides update-able join VIEWs. Access offers INNER JOIN on the UPDATE

Informix non-logged databases

Question: In a data warehouse, loading/transforming data is a significant process. Do Informix non-logged databases provide significant performance gains in loading and transforming data? Answer: YES! Though your needs may vary, most databases in data warehouses are not logged. There is very little change within the database that needs to

Set explain on fails

Question: Set explain on fails (sqlcode: 586 (I think) ISAM: 1) (Could not open sqexplain.out). We have plenty of disk space and file permissions. It even failed as “root” in /tmp with permissions of rwxrwxrwx. However, as user “informix” in the /tmp directory, but not directories with rwxrwxr-x, it succeeded.

Two questions on extend function/how Informix handles dates

Question: Both of the following questions deal with the extend function; more specifically, how Informix handles dates:1. I’ve used “extend(var, day to day)” in a program since December ’96 with no problems. But this week, it’s been crashing, with this message:1263: A field in a datetime or interval value is

Importance of DataBlades

Question: Why are DataBlades so important, as opposed to building application logic separate from the database? Answer: Though at first glance it appears that DataBlades and application logic operate similarly, DataBlades are not “application logic.”When I speak of “application logic” I mean statements such as“select a from b where conditionsif