The am_open purpose function
The database server calls am_open to initialize input or output prior to processing an SQL statement.
Syntax
mi_integer am_open(MI_AM_TABLE_DESC *tableDesc)- tableDesc
- Points to the index descriptor.
Usage
As part of the initialization, am_open might:
- Determine the reason or mode for the open, as described in The mi_tab_mode() accessor function.
- Allocate PER_STATEMENT memory for a user-data structure as described in Persistent user data.
- Open a database connection with the DataBlade
API mi_open() function.
To enable subsequent purpose functions to use the database, am_open can copy the connection handle that mi_open() returns into the user-data structure.
- Register callback functions to handle exceptions, as described in Handle the unexpected.
- Call the appropriate DataBlade API functions to obtain a file handle for an extspace or an LO handle for a smart large object.
Return values
- MI_OK
- Indicates success.
- MI_ERROR
- Indicates failure.
Related topics
See the description of:
- Memory allocation, callback functions, and the functions to open files or smart large objects in the HCL Informix® DataBlade API Programmer's Guide