The concepts in this guide apply for the DB2 version of the rating engine.

Data Fromat

product_code_call,description,cost,call_type

Data Upload

For the MySQL back-end, use phpMyAdmin to upload the data:

Log in to phpMyAdmin
Select the rate table
Click the import tab
Select the file that has the comma delimited values (CSV)
Set the number of lines to skip to 1
Select CSV radio button
Set the delimiter to “,”
Check the replace data with file box
Click Go

Upon successful import, a message diplaying the number of values imported, for example:
Import has been successfully finished, 1578 queries executed.

CREATE TABLE temp AS SELECT DISTINCT ON (email) * FROM table_to_deduplicate;
DROP TABLE table_to_deduplicate;
ALTER TABLE temp RENAME TO table_to_deduplicate;

Be mindful of the fact that this process will not preserve the constraints on the original table. So if you have indexes, NOT NULL attributes, primary keys, foreign keys, you’ll have to recreate them.

CREATE TABLE temp AS SELECT DISTINCT * FROM table_to_deduplicate;
DROP TABLE table_to_deduplicate;
ALTER TABLE temp RENAME TO table_to_deduplicate;

Be mindful of the fact that this process will not preserve the constraints on the original table. So if you have indexes, NOT NULL attributes, primary keys, foreign keys, you’ll have to recreate them.

• MyISAM: fastest disk based, least space requirement, non-transactional, slow crash recovery
• InnoDB: slowest engine, transactional, fastest crash recovery
• HEAP:fastest overall engine, limited by live memory, limited attribute types, no crash recovery

References:

• Which Storage Engine (table handler) to use?

When inserting into regular database systems, like Oracle, DB2, and even PostgreSQL, the omitted attributes from an INSERT are automatically set to default. Not so with MyISAM tables on MySQL. The syntax required by MySQL for an implicit default when multiple attributes are inserted is DEFAULT. For example:

INSERT INTO my_table VALUES (?,?,DEFAULT,?,DEFAULT)

will set the third and fifth parameters to default values.

Note that this has been only tested with the JDBC driver, and other database drivers might behave differently.

References:

• MySQL 5.0 Reference Manual

ALTER TABLE tbl_name MAX_ROWS=1000000000 AVG_ROW_LENGTH=nnn;

You have to specify AVG_ROW_LENGTH only for tables with BLOB or TEXT columns; in this case, MySQL can’t optimize the space required based only on the number of rows.

If you want to make the default larger, then you can set the mysqld engine parameter myisam_data_pointer_size = 7 in /etc/my.cnf (or whereever your MySQL server config file is). The setting of 7 will allow 256TB table size.

References:

1. Vbulletin Community Forum
2. MySQL 5.0 Reference Manual
3. Overcoming MySQL’s 4GB Limit

SELECT a,b INTO OUTFILE '/tmp/result.csv'  FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'  LINES TERMINATED BY 'n'  FROM test_table;

Reference: MySQL 5.0 Reference Manual

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.