Dr. Aasman point out: “NoSQL databases like Hadoop and Cassandra fail on joins. Big Enterprise, big web companies and big government intelligence organizations are all looking into big data to work with massive amounts of semi-unstructured data. They are finding that NoSQL databases are wonderful if one needs access to a single object in an ocean of billions of objects, however, they also find that the current NoSQL databases fall short if you need to run graph database operations that require many complicated joins. A typical example would be performing a social network analysis query on a large telecom call detail record database.”

The example code below assumes you have a “customer_cus” table and a “customer_archive_cua” table with at least two fields. It is a good idea to add a timestamp field to the archive table with DEFAULT now(), so that the date of deletion is captured.

CREATE FUNCTION archive_customer() RETURNS TRIGGER AS '
BEGIN
INSERT INTO customer_archive_cua (name_cua, address_cua)
VALUES (OLD.name_cus,OLD.address_cus);
RETURN NULL;
END;
' LANGUAGE 'plpgsql';
CREATE TRIGGER customer_archive_on_delete AFTER DELETE ON customer_cus
FOR EACH ROW EXECUTE PROCEDURE archive_customer();


References

• PostgreSQL (2nd Edition) (Developer’s Library)

INSERT INTO new_table
SELECT col1,col2 FROM source_table
WHERE col1='something';

and if you need to populate query variable, you need to use SELECT INTO, like in this example:

SELECT * INTO :var1, :var2, :var3FROM table_name
WHERE col1= 'something'; 

Source: DB2 Documentation

It goes as follows:

1) create table T1 like T;This creates an empty table T1 with indexes ndx1,ndx2,ndx3 and ndx4.2) alter table T1 drop index ndx3;This drops index ndx3 on the empty T1, which should be instantaneous.3) insert into T1 select * from T;This will populate table T and load all three(3) indexes for T1 in one pass.4) drop table table T;5) alter table T1 rename to T;

An alternative ugly hack is to start the drop index, kill the database server.  That will crash the table on which the drop index was.  The crashed table can be recovered by running mysiamchk.

reliability is key to gain customers' loyalty

becomes

reliability is key to gain customers'' loyalty