Purpose
Initializes a handler for table scanning.
Synopsis
virtual int rnd_init
( |
scan); |
|
Description
This is the rnd_init method.
rnd_init() is called when the system wants the storage engine to
do a table scan.
Unlike index_init(), rnd_init() can be called two times without
rnd_end() in between (it only makes sense if scan=1). then the
second call should prepare for the new table scan (e.g if
rnd_init allocates the cursor, second call should position it to
the start of the table, no need to deallocate and allocate it
again
Called from filesort.cc, records.cc, sql_handler.cc,
sql_select.cc, sql_table.cc, and sql_update.cc.
Parameters
Return Values
There are no return values.
Usage
This example is from the CSV storage engine:
int ha_tina::rnd_init(bool scan)
{
DBUG_ENTER("ha_tina::rnd_init");
current_position= next_position= 0;
records= 0;
chain_ptr= chain;
DBUG_RETURN(0);
}
