[[TracNav(TOC)]]

= Rasdaman FAQ =

Here you can find answers to some of the most frequently asked questions about `rasdaman`. If you have a question not answered on this page, you can ask it on the MailingLists. You may want to consult these sources of information in addition:
   * [wiki:Install Installation guide]
   * [wiki:RequiredPackages Further packages required]
   * [wiki:FormatsSupported Data formats supported]

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== Installation ==

=== Using automake I get an error message "directory should not contain /" === 

 * Probably you have an outdated automake version installed, we have seen such problems with 1.7.9. Upgrade to at least 1.10.1.

=== ''./configure'' complains that some further packages are required during installation === 

 * These are summarized on the [wiki:RequiredPackages] page.

=== ''./configure'' complains about missing ''curses'' ===
... although ''ncurses'' is there.

 * You have run into a [http://bugs.gentoo.org/67481 bug in the ncurses package]; in /usr/lib, manually create symlinks ''libcurses.a -> libncurses.a'' and ''libcurses.so -> libncurses.so''.

=== ''configure'' complains that some required files, like install-sh, cannot be found ===  

 * retry ''./configure'' after running
{{{
$ automake --add-missing
}}}

=== make complains about missing Makefiles ===
...such as in the time/ directory, and issues error messages like "No rule to make target `../time/libtime.a', needed by `rasserver'.  Stop.".

 * retry ''./configure'' after running
{{{
$ autoreconf
$ automake
}}}

=== I get C++ compilation errors. === 

 * Make sure you use the proper compiler version (see [wiki:RequiredPackages]). GNU folks have a relaxed view on backwards compatibility even with minor release changes, and we have experienced problems related to this in the past.

=== On a 64bit architecture I get linkage errors (e.g., when linking GDAL with the rasdaman driver) like "relocation R_X86_64_32 against `.bss' can not be used" === 

 * Make sure you use the proper compiler version (see [wiki:RequiredPackages]). GNU folks have a relaxed view on backwards compatibility even with minor release changes, and we have experienced problems related to this in the past.
 * retry ''./configure'' with these extra flags:
{{{
$ ./configure CFLAGS=-fPIC CXXFLAGS=-fPIC LDFLAGS=-fPIC ...other options...
$ make install
}}}


== PostgreSQL ==

=== I get a link error, function ECPGget_connection cannot be found === 

 * What appears to have happened is that in PostgreSQL 8.3.0 they removed ECPGget_connection and they have reintroduced it by 8.3.7. So PostgreSQL versions 8.3.0 up to (but excluding) 8.3.7 cannot be used.

=== I want to use a different version of PostgreSQL. Is that possible? === 

 * You need to include a different JDBC postgresql driver (as a JAR) in the libraries folder and update the Makefile as needed. Then you can try out another PostgreSQL version, it may or may not work. Let us know your experiences to update this information!

=== When running the script "create_db.sh", I get !''AdminIf'' related error === 
...more specifically, ''Creating base RASBASE...Warning/error in AdminIf Connect: SQLSTATE: 08001 SQLCODE: -402''

 * There are several possible reasons:
  1. '''Execution permissions.''' Run the script as the user owning the postgresql processes. Use '''only''' that user for further work with rasdaman (see Installation Guide). If you use Ubuntu and installed postgres with apt-get, then logging in as user '''postgres''' is an option; I personally like to have a separate user ''rasdaman'' for this purpose where I also can set paths etc. to the executables once and for all. (The postgres db does not allow full access to rasdaman tools, because they do not run under the administrative user that launched the db server process.)
  2. '''Blocked incoming connections.''' Another cause of the problem might be that postgres does not allow incoming connections. If you have Postgres v8 or more recent, modify file "postgresl.conf" and set (uncomment) the option 
{{{
listen_addresses = 'localhost'
}}}
  3. '''TCP-IP connection.''' If you have Postgres v7, set (uncomment) the following option:
{{{
tcpip_socket = true
}}}

=== I get "wrong connect string" error when first running ''rasdl'' === 
When I first try to run rasdl (or the rasdaman server, for that matter) against PostgreSQL after installation, the log says "server ok" but "wrong connect string"

 * There are several possible reasons:
  1. '''Port:''' Running a database cluster on a separate port requires proper setting of environment variable PGPORT to allow for communication between rasdaman and PostgreSQL. (thanks to Mario Uhlig!)
  2. '''Socket directory:''' using '/var/lock/postgresql' as socket directory makes rasdl fail for a reason still to be found. Switching back to the default socket dir '/var/run/postgresql' resolves the issue. (thanks to Alexander Herzig!)


== Rasql queries ==

=== My query which uses ''log'' doesn't work === 
{{{
for c in (rgb) return encode(log(c.0), "jpeg")
}}}

 * The '''log''' function needs positive numbers as arguments, and will return -Infinity if the argument is 0. You need to make sure that the input does not contain any zeros. You can check that using the query
{{{
for c in (rgb) return count(c.0 = 0)
}}}
 '''''Solution''''' : Add 1 to the input:
{{{
for c in (rgb) return encode(log(c.0+1), "jpeg")
}}}

=== When using division "/" as an induced operation I get integer results instead of floats. === 

 * Division of two integers yields an integer. If you want to have a float result then you need to cast the operands (that is: at least one of them) to float or double.

=== My insert query produces error 821 (cell type mismatch) === 
... although I provide a TIFF file with correct pixel type:
{{{
insert into FloatCollection values inv_tiff( $1 )
}}}

 * You need to provide an explicit cast (see section 9.8 in the Rasql Guide); a correct phrasing of this query is:
{{{
insert into FloatCollection values (float) inv_tiff( $1 )
}}}

=== How does the Storage Layout Language work? === 

 * See [http://kahlua.eecs.jacobs-university.de/trac/rasdaman/attachment/wiki/FAQ/sstdm2010.pdf this description] while the manual is not yet updated.


== Rasj and Java ==

=== Overflow when unsigned bytes are retrieved with rasj === 
If I send the query ''select max_cells(c.0) from rgb as c'' via command line (rasql utility), then the result is 255 as expected; if I send this query via RasJ, then the result is -1.

 * Java does not have an 8-bit unsigned data type. Byte is a signed 8 bit and hence 255 is represented as -1. What you can do is to transform bytes to char by adding 2^8 if the 2^7 bit is set. Tested, works.

=== I get class version incompatibility error messages === 
I get weird error messages from the Java runtime system which seems to hint at class version incompatibilities, such as "Class version error" or "Class not found".

 * There might be a conflict with the locally provided libraries, to be found at directory $PETASCOPE/lib. Check them, and if you find a mismatch then remove them and use the resp. libraries of your local installation instead. Alternatively, consider upgrading your Java SDK to version 1.6.


== Data formats ==

=== HDF4 is said to be supported, but rasdaman reports an error ===
...when trying to use ''hdf()'' or ''inv_hdf()'' - what can I do?

 * HDF4 needs to be compiled in explicitly. Re-generate rasdaman saying 
{{{
$ make clean
$ autoreconf
$ ./configure --with-hdf4 ...other options...
$ make
$ make install
}}}


=== NetCDF is said to be supported, but rasdaman reports an error ===
...when trying to use ''netcdf()'' or ''inv_netcdf()'' - what can I do?

 * NetCDF needs to be compiled in explicitly. Re-generate rasdaman saying 
{{{
$ make clean
$ autoreconf
$ ./configure --with-netcdf ...other options...
$ make
$ make install
}}}
   Supported NetCDF library version is 4.0+. It provides netcdf4 (including HDF, classic, and 64) and netcdf3 (as the API is backwards compatible).
   Limitations: only atomic cell types, but no struct types are supported at this moment; and metadata are not preserved (they have to be stored separately in PostgreSQL tables)


== Submitting Patches ==

=== I want to submit a patch, how do I do this? ===

 1. Set your credentials (ie, your name, YOUR_FULL_NAME, and email address, EMAIL):
{{{
$ git config user.name "YOUR_FULL_NAME"
$ git config user.email EMAIL
}}}
 2. When you commit your changes to your local copy put a meaningful message:
{{{
$ git commit -a -m "commit message"
}}}
 3. Then you can make the patch, e.g:
{{{
$ git-format-patch HEAD~1 
}}}
 4. Finally you can submit the generated patch to the [http://kahlua.eecs.jacobs-university.de/trac/rasdaman/patchmanager/ rasdaman patchmanager]
 
 '''Important:''' avoid submitting generated files like ''configure, Makefile.in'', etc. in your patch, unless the corresponding source has been really modified.