Sybase ETL 4.8 supports using multiple writers for loading data into an IQ database. IQ Multiple Writer allows parallel loading of Sybase IQ tables and is faster than sequential loading.
The following IQ ETL components have been enhanced to support loading data using multiple writers:
IQ Loader File via Load Table
IQ Loader DB via Insert Location
DB Bulk Load - Sybase IQ
To use the multiple writer functionality, you must have create table and execute sp_iqstatistics stored procedure privilege in the target IQ database. This is because ETL creates two tables (ETL_MULTIPLEX_STATE and ETL_MULTIPLEX_VERSION) in the IQ database. Each row in the ETL_MULTIPLEX_STATE table displays information about the IQ writer selected by the ETL gridnode that is removed automatically after each execution. In case, gridnode crashes due to unexpected error, you must clean the state data in the table, manually.
Use Sybase Central to set the create table and execute sp_iqstatistics permission for selected users:
Connect to the Sybase IQ 15.0 server.
Expand Users & Groups and then select the user for whom you want to set the create table permission.
Right-click the user and select Properties.
Select Authorities tab and check Resource option to give the permission to the user to create database objects in the IQ database.
Next, select Permissions tab and then select Procedures & Functions to see a list of all the available permissions.
Select sp_iqstatistics and click Execute to give the permission to the user to execute the stored procedure in the IQ database.
Click OK to save the settings.
For details on multiplex execution configuration, see “Configuring IQ multiple writers for loading data” in Chapter 5, “Components” of the Sybase ETL 4.8 Users Guide.
For optimum performance, use multiple writers when you must load multiple tables in IQ, such as in the following scenarios:
If you have selected more than one table from the source database and you are migrating to more than one table in the target IQ database.
If you have created a job with a multiproject component involving multiple tables, or if you have selected multiple projects that are linked to parallel execution topology, for job execution.
