The plug-in that is being used must support delayed batch creation of plug-in index. This facility cannot be used if it is not supported by the plug-in.

At the time this manual was issued, only the following plug-in supports this facility:

• HiRDB Text Search Plug-in

Because data addition processing for the plug-in index can be skipped, the UAP execution time for adding or updating a large amount of row data (table data creation time) is reduced.

This facility can be applied only to row addition or update processing. In other words, it is applicable to the following SQL statements:

• INSERT statement
• UPDATE statement

This facility is not applicable to row deletion processing (DELETE statement).

• This facility is applied to batch processing that involves addition or updating of a large amount of data in a table for which an eligible plug-in index is defined.
• When the HiRDB Text Search Plug-in is used, this facility is effective for batch processing that involves addition or updating of a large amount of data in a table for which the plug-in index defined. However, if the plug-in index is to be updated and then the contents are to be referenced during online processing, the differential index facility that is provided by HiRDB Text Search Plug-in is effective.

The following limitations apply to delayed batch creation of plug-in index.

(a) The plug-in index is not usable for retrieving an added or updated row until batch creation of the plug-in index is completed

Once the UAP has executed, conformity between the table's data and the plug-in index's data is lost until batch creation of plug-in index has been completed.^#

If the plug-in index is used to retrieve an added or updated row during this period of nonconformity, an invalid result will probably be returned. For this reason, it is important that the plug-in index not be used to retrieve added or updated rows until batch creation of plug-in index is completed.

Valid processing results can be obtained as long as the plug-in index is not used. Also, the plug-in index can still be used to retrieve a row that was not added or updated by the UAP.

#: When data is added, the plug-in index's data remains in the same status it was in before the UAP executed. When data is updated, the plug-in index's data is placed in deleted status until it is updated.

Thus, for an added or updated row, there is a loss of conformity between its table data and its plug-in index data.

(b) An ordinary UAP cannot update the plug-in index until batch creation of the plug-in index is completed

The plug-in index cannot be updated by an ordinary UAP (UAP for which delayed batch creation of plug-in index is not specified) until batch creation of plug-in index is completed. However, the PURGE TABLE statement can be executed.

(c) UAPs cannot be executed concurrently on the same table

The index information files are placed in the lock mode (EX). Therefore, UAPs that use this facility cannot be executed concurrently on the same table.

(d) No more data loading can be executed until batch creation of the plug-in index is completed

Data loading cannot be performed until batch creation of the plug-in index is completed. However, if the table is row-partitioned, you can use the delayed batch creation facility to perform UAP-based processing and to load additional data into RDAREAs in which no data is stored.

(e) Plug-in index names must not be changed until batch plug-in index creation is executed

If a plug-in index name is changed using ALTER INDEX before batch plug-in index creation is executed, batch plug-in index creation cannot be executed for the index information file that is output when a UAP was executed. If a plug-in index name was changed before batch creation, return the plug-in index name to the original name, execute batch plug-in index creation, and then change the plug-in index name again.

(f) The name of the RDAREA storing plug-in indexes must not be changed until batch plug-in index creation is executed

If the database structure modification utility (pdmod command) is used to change the name of the RDAREA storing plug-in indexes before batch plug-in index creation is executed, batch plug-in index creation cannot be executed. If the RDAREA name was changed before batch creation, return the RDAREA name to the original name, execute batch plug-in index creation, and then change the RDAREA name again.