Inquiry and error functions

Inquiry and error functions

 

Useful List of Ab Initio Inquiry and Error Functions. 

all_defined	force_error	is_failure	size_of
all_null	invocation_number	is_null	write_to_log
fail_if_error	is_blank	is_valid
first_defined	is_bzero	last_error
first_without_error	is_defined	length_of
force_abort	is_error	null_if_error

 

SQL Commands Classification

 

DDL

Data Definition Language (DDL) statements are used to define the database structure or schema. Some examples:

• CREATE - to create objects in the database
• ALTER - alters the structure of the database
• DROP - delete objects from the database
• TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed
• COMMENT - add comments to the data dictionary
• RENAME - rename an object

DML

Data Manipulation Language (DML) statements are used for managing data within schema objects. Some examples:

• SELECT - retrieve data from the a database
• INSERT - insert data into a table
• UPDATE - updates existing data within a table
• DELETE - deletes all records from a table, the space for the records remain
• MERGE - UPSERT operation (insert or update)
• CALL - call a PL/SQL or Java subprogram
• EXPLAIN PLAN - explain access path to data
• LOCK TABLE - control concurrency

DCL

Data Control Language (DCL) statements. Some examples:

• GRANT - gives user's access privileges to database
• REVOKE - withdraw access privileges given with the GRANT command

TCL

Transaction Control (TCL) statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions.

• COMMIT - save work done
• SAVEPOINT - identify a point in a transaction to which you can later roll back
• ROLLBACK - restore database to original since the last COMMIT
• SET TRANSACTION - Change transaction options like isolation level and what rollback segment to use

How to create and use a lookup catalog

How to create and use a lookup catalog

Lookups defined in a graph are always available to the graph. A shared catalog is used when one graph creates and publishes lookups that other graphs can use.

m_catalog commands help to manage catalog file. 

Lookup Catalog files gives performance improvement in data processing. It separates reference data refresh from day-to-day data processing. 

Separating reference data refresh from main processing helps to avoid concurrency, dead locks with database.