FAQ (English)

General Question

Can I use Senna for business?

Yes, you can use it by following the LGPL 2.1 license. We're welcome you to use Powerd by Senna banner . Brazil is doing consulting and supports for profit. Please contact us for detail information from contact form

I made an application for Senna.

Not only patches for Senna, we also much appliciate developing applications related to Senna. If you correspond with us about your work, we will introduce it.

Question about Senna uses

Can I use Senna without MySQL?

You can use Senna without binding to MySQL. Senna can work in C code, and various types of languages are able to use for binding. We also produce binding with PostgresSql named ludia.

Search doesn't work well.

It might be occurred by following cases

Character sets specified in /var/senna/senna.conf or c:\senna\senna.conf, for MeCab's dictionary, and for a target index are different.
Using MeCab dictionary which is made with wrong character sets.
Senna reads old format index, when Senna loses compatibility of indexes by version up.

If you encouter these kind of phenomenon, you should check those encodings are matched or not. And operate below.

If you're using Senna alone

Delete index files, and restructuring them.

If you're using MySQL + Senna

Drop full text index, and then do rcreate it.
Stop MySQL server. Restructuring index by myisamchk -r

Is there a system that can search internal contents of a server like Namazu?

No, not yet. However Perl might be able to achieve by using File-Extract module and Tie-Senna. In this case, MySQL is not required.

Can I use huge document sets?

Senna is designed to be able to handling huge document sets. We recommend to set below:

For MySQL binding, patch the 2ind-patch, if you need to do searching refinement, getting numbers of item by count(*), and sorting by any items except score order.If you use mysql with 2ind-patch, you have to check key_buffer_size parameter is properlly chooned.
Set INITIAL_N_SEGMENTS suitable size. That can find in senna.conf
Use Linux 2.6 or above, to enable user level cache (currently it's not stable).
Breakup contents.

About MySQL Binding

I get a error during MySQL compile

MySQL + Senna is possibly shows up error like this

myisamchk.o: In function `main':
myisamchk.c:(.text+0x72): undefined reference to `sen_init'
libmyisam.a(mi_open.o): In function `mi_open':
mi_open.c:(.text+0x14e7): undefined reference to `sen_log'
...

What the reasons are:

You didn't run autotools (automake or autoconf), before you run configure.
Linker cannot find libraries.

Second one probably avoids by these provision.

Do "ls /usr/local/lib", and confirm existence of libsenna.a
Add "/usr/local/lib" line in /etc/ld.so.conf as root. If there is no file, create as new file.
run "ldconfig -m /usr/local/lib" as root

How can I use AND Search, OR Search, or NOT Search?

There is two ways:

Expand WHERE clause as WHERE MATCH(a) AGAINST('text') AND NOT MATCH(a) AGAINST('text') OR MATCH ...
Use IN BOOLEAN MODE (Refer query syntax for detail grammar)