Need clarification on FullText information

[bnownlater]

I am using SHOW INDEX on one of my tables that I have a FULLTEXT index on.

Table: article
non_unique: 1
key_name: THEARTICLE
seq_in_index: 1
column_name: THEARTICLE
collation: A
Cardinality: NULL
sub_part: 1
packed: NULL
comment: FULLTEXT

I read that sub_part means:
"The prefix length in bytes, if only a prefix of the column is indexed. This is NULL if the entire column is indexed."


So is this telling me that my FULLTEXT index is only looking at the first byte of information. I thought that when you use FULLTEXt indexing it indexes the entire thing. Somebody please explain! Thanks.

 

[hos2]

why is it necessary that you need an index on a fulltext field anyway ????????

indexes should be used carefully and are mostly used on keys only. when you get performance problems you could try to create some indexes on the most frequently used keys