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Siebel Business Analytics Server Administration Guide > Query Caching in the Analytics Server > Cache Event Processing with an Event Polling Table > Setting Up Event Polling Tables on the Physical DatabasesThis section describes how to set up the Analytics Server event polling tables on physical databases. Polling Table StructureYou can set up a physical event polling table on each physical database to monitor changes in the database. You can also set up the event table in its own database. The event table should be updated every time a table in the database changes. The event table needs to have the structure shown in Table 35; some columns can contain null values depending on where the event table resides. The column names for the event table are suggested; you can use any names you want. However, the order of the columns has to be the same as shown in Table 35. Sample CREATE TABLE statements to create an event polling table are shown in Sample Event Polling Table CREATE TABLE Statements. The Analytics Server needs to have read and write permission on the event polling table. The server reads the event table at specified intervals to look for changed data. Applications add rows to the event table when database tables are modified (for example, during a load operation). When there are rows in the event table, there is changed data in the underlying databases. The server then invalidates any cache entries corresponding to the changed physical tables and periodically deletes obsolete rows from the event table. The next time it checks the event table, the process repeats. NOTE: A single event polling table cannot be shared by multiple Analytics Servers. When you set up multiple Analytics Servers, you need to create an event polling table for each one. To allow Analytics Server to have write access to the event polling table but not to any other tables in a database, perform the following tasks:
The Analytics Server will have write access to the event polling table, but not to any tables that are used to answer user queries. Sample Event Polling Table CREATE TABLE StatementsThe following are sample CREATE TABLE statements for SQL Server 7.0 and Oracle 8i. These CREATE TABLE statements create the structure required for a Analytics Server event polling table. In these statements, the table created is named UET. It resides in the same database as the physical tables that are being updated. NOTE: The column lengths need to be large enough to represent the object names in your repository. The following is the CREATE TABLE statement for SQL Server 7.0: // SQL Server 7.0 Syntax The following is the CREATE TABLE statement for Oracle 8i: // Oracle 8i syntax You might need to modify these CREATE TABLE statements slightly for different versions of SQL Server and Oracle, or for other databases. Additionally, if you want to specify any explicit storage clauses, you need to add the appropriate clauses to the statements. |
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