If you want to test fragmented indexes, use the SQL syntax in Supporting Fragmentation. You can provide support in the access method for CREATE INDEX statement keywords that effect transaction processing. If a CREATE INDEX statement specifies the LOCK MODE clause, the access method must impose and manage locks during data retrieval and update. To determine the state of an index during transaction processing, the access method calls VII functions to determine the lock mode, data-entry constraints, referential constraints, and other state information.
A user sets the isolation level with commands such as SET ISOLATION and SET TRANSACTION or with configuration settings in the ONCONFIG file. It is recommended that you document the isolation levels that the access method supports, as mi_scan_isolevel() describes. For information about setting isolation levels, refer to the IBM Informix: Guide to SQL Syntax and the IBM Informix: Guide to SQL Tutorial.
A database server administrator can use the ONCONFIG file to set defaults for such things as isolation level, locking, logging, and sbspace name. For information about defaults that you can set for the test-environment ONCONFIG file, refer to the IBM Informix: Administrator's Guide.
For information about SQL statements and keywords that your access method can support, refer to the IBM Informix: Guide to SQL Syntax. For information about the VII functions that determine which statements and keywords the user specifies, refer to Descriptor Function Reference.
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