Have you ever needed to know how often a stored procedure is called, or whether it is used at all? This is easy to find out within the database, but of course an unknown number of outside applications may check in from time to time and they may be have been written by end users. […]
An ETL batch should not fail because of minor source data errors. In data warehousing it is assumed that there will be data quality issues. These should be dealt with. If they are not handled properly the batch may break on flaws which have no importance in reporting terms. Oracle’s DML Error Logging feature has […]
Christmas is not too far away now, and I would like to dedicate this haiku to any of my Oracle developer and DBA friends working the holiday period, and who may be from their beds “untimely ripped” to fix something or other:
The requirement here is to concatenate multiple rows into a single string, not simply to do a concatenation of columns within a row, which is easy with the the “+” operator or T-Sql’s CONCAT function. Concatenation of rows is now very straightforward – I believe the change came in with Sql 2012.
In a data warehouse you may have to drop columns on very large tables (try to avoid it if you can), and the size of the table may cause complications. The most obvious is the time it may take to do a straightforward ALTER TABLE DROP COLUMN statement. You probably don’t want to wait for […]