Category: Oracle

  • Monitoring error logs in Oracle and Sql Server

    In Oracle, there are 3 places that I know of that are important for monitoring: the bdump, where background process error is stored; udump, where user trace error is dumped; and cdump, the core dump, where Oracle internal error is dumped. cdump is in the binary format, you can use “strings -a” to look at […]

  • Assign SELECT results into variables

    I mentioned here that SELECT INTO in Sql Server is functionally similar to CREATE TABLE AS in Oracle. Oracle also has SELECT INTO, but it is used for assigning query results to a variable. Here is a PL/SQL code snippet: declare MyVariable varchar2(20); Begin select ColumnName into MyVariable from MyTable where MyID = SomeInteger; dbms_output.put_line(‘Hello […]

  • CTAS and Select Into

    In both Oracle and MySQL, you can do: create table T1 as select * from T1 This CREATE TABLE AS statement basically clones table T1 with its structure and data in T2. This can be pretty handy at times. The equivalent of that in Sql Server is SELECT INTO. For example, you can do: select […]

  • Delete permission implementation differences

    I mentioned when grant statements take into effect in Sql Server, MySql, and Oracle here. I found out recently that there are some implementation differences when you grant only delete permission on a table to a user. MySql and Sql Server do this the same way, whereas Oracle is different. Suppose you have: 1. Table […]

  • When does grant statement take into effect

    In both Sql Server and Oracle, permission changes to a user take into effect right away, even when said user is connected at the time you made the change. In MySql, it is a little different, depending on how the permissions are given. If you use the GRANT statement, then it takes into effect right […]