vB search or MySQL Fulltext search?

[Sonnie]

Which of these is better and what are the differences?

I see the explanation here:

Search Type
Fulltext searching uses a search index that is constructed by MySQL itself, whereas vBulletin's own search feature uses its own index.

Delete Indices
When switching a forum to the fulltext search mode, you will want to consider emptying the indices that the default search engine built. These indices are not used by the fulltext search and consume a large portion of your database. You should be certain that you are going to permanently use the fulltext search before removing these indices since, generally, it takes a lot of time and server load to rebuild these indices. Another consideration is during any time that the fulltext option is enabled, these indices will not be updated by any new posts. Using fulltext search for an extended period of time will leave these indices stale and you may still wish to rebuild them.

You can also empty these indices in the Update Counters section of Maintenance.

You may want to optimize the postindex and word tables afterwards by going to the Repair / Optimize Tables section of Maintenance.

Ole dumb hillbilly me... this doesn't tell me a whole lot.

Thanks!

[Peggy]

ha, doesn't tell me much either.


hey NOPPID!?!

[Noppid]

I didn't do the research, I'm not in a position to give any feed back unfortunatly.

[Coder1]

"Fulltext" search refers to the indexes MySql builds against the database. Vbulletin can use that, if you like. The "Default Search Engine" is vBulletin code that it uses to search. In other words, for whatever reason, vBulletin coded their own search tool and the database indexes to support it. My guess is that they did this because MySql is just one of the databases they support, and not every database provides a fulltext search function.

So, IF you want to use the MySql built-in search, you should delete the default Vbulletin indexes, as described, because they are just taking up space and not doing anything.

So, should you use the MySql search? I don't know, since I haven't performance tested this.

My suggestion is to leave things exactly as they are unless you are experiencing a performace problem that you think is tied to the search mechanism.

[Hell³]

I did changed the default vb search to the fulltext one. DB backups decreased substantially in size since I dropped the table indeces. Performance wise, there was a small but noticeable improvement. Don't really know how much impact does it have on performance on bigger forums.

[Sonnie]

Is there any meaning behing the name "fulltext"? Is vBulletin a part text search?

[Hell³]

I believe it's called that way since when you define a field as a fulltext index the whole contents become searchable.

[Coder1]

No, no meaning other than... well, yes, there is a meaning, but it isn't in contrast to vBulletin. MySql is a database. With most databases, to get information you have to do a specific query. MySql ALSO has the ability to do a "full text search". They added that as a general feature, it has nothing to do with vBulletin per se. They called this feature "fulltext".

vBulletin coded a search feature in PHP, just as a general feature of the forum software. It is a full-text search in that it will search the entire forum. This is a general feature of the software, regardless of which database you use, because not every database offers such a feature.

So, you have two complete searching mecanisms, and can choose which one to use.

I'll repeat my advice: if you're unclear on any of this, don't mess with it.

[Peggy]

I'll repeat my advice: if you're unclear on any of this, don't mess with it.

NO problem!

[Sonnie]

It appears there are better wild card features for "fulltext" search than for vB, although I don't know all the codes for either. I do know that some of the codes I use on some vB sites will not work on our site.

I've asked vB for a full list of the codes... they have responded that they are gathering them up. Seems like they would publish these in a pop-up on the search page. It seems to have been available this way in the older versions as far back as 3.0.

[Sonnie]

In case anyone might get to wondering what wild card operators will work with the fulltext boolean search in vB...

• + A leading plus sign indicates that this word must be present in each row that is returned.
• - A leading minus sign indicates that this word must not be present in any of the rows that are returned.
• (no wild card) By default (when neither + nor - is specified) the word is optional, but the rows that contain it are rated higher. This mimics the behavior of MATCH() ... AGAINST() without the IN BOOLEAN MODE modifier.
• > < These two operators are used to change a word's contribution to the relevance value that is assigned to a row. The > operator increases the contribution and the < operator decreases it. See the example below.
• ( ) Parentheses are used to group words into subexpressions. Parenthesized groups can be nested.
• ~ A leading tilde acts as a negation operator, causing the word's contribution to the row's relevance to be negative. This is useful for marking “noise” words. A row containing such a word is rated lower than others, but is not excluded altogether, as it would be with the - operator.
• * The asterisk serves as the truncation operator. Unlike the other operators, it should be appended to the word to be affected.
• " A phrase that is enclosed within double quote (‘"’) characters matches only rows that contain the phrase literally, as it was typed. The full-text engine splits the phrase into words, performs a search in the FULLTEXT index for the words. The engine then performs a substring search for the phrase in the records that are found, so the match must include non-word characters in the phrase. For example, "test phrase" does not match "test, phrase".

• If the phrase contains no words that are in the index, the result is empty. For example, if all words are either stopwords or shorter than the minimum length of indexed words, the result is empty.

• 'apple banana' Find rows that contain at least one of the two words.
• '+apple +juice' Find rows that contain both words.
• '+apple macintosh' Find rows that contain the word “apple”, but rank rows higher if they also contain “macintosh”.
• '+apple -macintosh' Find rows that contain the word “apple” but not “macintosh”.
• '+apple +(>turnover Find rows that contain the words “apple” and “turnover”, or “apple” and “strudel” (in any order), but rank “apple turnover” higher than “apple strudel”.
• 'apple*' Find rows that contain words such as “apple”, “apples”, “applesauce”, or “applet”.
• '"some words"' Find rows that contain the exact phrase “some words” (for example, rows that contain “some words of wisdom” but not “some noise words”). Note that the ‘"’ characters that surround the phrase are operator characters that delimit the phrase. They are not the quotes that surround the search string itself.

• Some words are ignored in full-text searches:

• Any word that is too short is ignored. The default minimum length of words that are found by full-text searches is four characters.
• Words in the stopword list are ignored. A stopword is a word such as “the” or “some” that is so common that it is considered to have zero semantic value. There is a built-in stopword list, but it can be overwritten by a user-defined list.