
The vt_create_text_index procedure adds a text index to an existing table.
There can at most be one text index per table, including super tables and
subtables.
  
The table argument is a string naming the table. The column is the name of the column
to index. The id_col should be the name of a unique integer row identifier column.  If null,
the system will either add such a column or use an existing integer primary key if one
is available.  The is_xml argument, if non-0, specifies that the values of the indexed column
should be checked for XML well formedness and that the XML structure should be taken into account in indexing the
values.
  
Use the CREATE TEXT INDEX statement as an alternative to the vt_create_text_index function.
  
In order for a table to be referenced in a text index it must have
a uniquely identifying integer key.  If the table in question has such a 
key this can be used as the id column.  If there is no such column this 
procedure makes one.  Using a previously existing identifier column saves 
space and if that is the primary key of the table this also saves in 
retrieval time.
	
If the table being indexed has a single part integer primary key 
vt_create_text_index will automatically use this as the identifier.  Note 
that the zero and negative numbers may not be used as identifier values.
	
Creating the index will read through the table@s contents and generate 
the index.  When the table is changed the index can either be updated after 
each change or periodically, depending on the application needs.  The rationale 
for background maintenance of the text index is that it is up to several times
more efficient to maintain a text index in batches of several changed documents 
than after each single document change.  The default maintenance mode is 
synchronous, meaning that each insert, delete or update of the indexed column 
will be immediately reflected in the index.  This mode can be set using 
the vt_batch_update() procedure.
The mode should be set to batch if there are 
any massive operations on the table.
	
It will create two additional tables:
	
 and
	
 and two procedures:
	
 and
	
The table <datatable>_<datafield>_WORDS contains the full text index data.

The table VTLOG_<datatable>_<datafield> is an update tracking table, similar to the snapshot log table but using the key column instead of the primary key.
in the transaction semantics section that there is the sync mode for the purpose of creating a text index.