We can also use the SQL-99 “WITH clause” instead of temporary tables. The Oracle SQL “WITH clause” will compute the aggregation once, give it a name, and allow us to reference it (maybe multiple times), later in the query. The SQL-99 “WITH clause” is very confusing at first b...
Alocation_idvalue that appears multiple times in either or both queries (such as '1700') is returned only once by theUNIONoperator, but multiple times by theUNIONALLoperator. INTERSECT Example The following statement combines the results with theINTERSECToperator, which returns only those rows retu...
TheBULK COLLECT INTO clause can improve the performance of queries that reference collections. You can use BULK COLLECT INTO with tables of scalar values, or tables of %TYPE values. The PL/SQL block inExample 6-10queries multiple values into PL/SQL tables, with and without bulk binds. Withou...
It is still possible for SQL operations, such as hash aggregation, sort, hash join, creation of cursor-duration temporary tables for theWITHclause, and star transformation to spill over to disk (specifically to the global temporary tablespace on shared disks). Management of the local temporary ta...
If you use a version of Oracle Database 10g Release 2 before 10.2.0.3, then you might encounter an issue with a Full Outer Join that causes severe database performance issues and appears to hang the database when the BI Server sends to the database SQL queries that include WITH clauses....
The BULK COLLECT INTO clause can improve the performance of queries that reference collections. You can use BULK COLLECT INTO with tables of scalar values, or tables of %TYPE values. The PL/SQL block in Example 6-10 queries multiple values into PL/SQL tables, with and without...
--delete clause : Set the DELETE clause to apply to the Oracle query to be applied before importing data. Can be used multiple time. --oracle_fdw_prefetch: Set the oracle_fdw prefetch value. Larger values generally result in faster data transfer at the cost of greater memory utilisation at...
The challenge here is there could be any size gap between rows. It’s possible to solve this using recursive queries or themodelclause. But I prefer to useSQL pattern matching. This looks like: Copy code snippet Copied to Clipboard
To simplify access to data stored in multiple tables. To implement specific security for the data in a table (e.g., by creating a view that includes a WHERE clause that limits the data you can access through the view). Starting with Oracle9i, you can use fine-grained access control to ...
SOFTWARE ARCHITECTURE There are multiple components to eDoc. The web presentation layer, which provides Title Starter Search capabilities is developed utilizing J2EE framework for IBM Websphere clustered JVM to communicate with the database via Oracle JDBC Thin 10.2 drivers. eDoc also has another ...